Method and system for reactive distillation of biological crude oil

文档序号：914096 发布日期：2021-02-26 浏览：25次中文

阅读说明：本技术 用于生物粗油的反应性蒸馏的方法和系统 (Method and system for reactive distillation of biological crude oil ) 是由李春柱 R·古纳万 Z·王 S·王 L·张 M·M·海森 H·王于 2019-05-14 设计创作，主要内容包括：本公开提供了用于反应性蒸馏通过热处理包括生物质的含碳进料形成的生物粗油的方法和系统。首先,将生物粗油在升高的压力下加热。接着,使源自生物粗油的化学反应的物质的分压降低,以使得生物粗油蒸馏,以形成不同的馏分。反应性蒸馏可与生物粗油的进一步升级和利用整合。对于生物粗油的反应性蒸馏与生物粗油的氢化处理或重整的整合,给出了两个示例。(The present disclosure provides methods and systems for reactive distillation of biological crude oil formed by thermally treating carbonaceous feed including biomass. First, the raw bio-oil is heated under elevated pressure. The partial pressure of the substances originating from the chemical reaction of the raw bio-oil is then reduced so that the raw bio-oil is distilled to form different fractions. Reactive distillation can be integrated with further upgrading and utilization of the bio-crude. Two examples are given for the integration of reactive distillation of the bio-crude with hydrotreating or reforming of the bio-crude.)

1. A method of reactive distillation of a biocrude oil, the method comprising:

providing a biocrude formed by heat treating a carbonaceous feed comprising biomass;

heating the raw bio-oil at an elevated pressure; and

reducing the partial pressure of a substance originally present in the raw bio-oil and formed from the reaction of the raw bio-oil such that the substance distills to form a different fraction.

2. A method of reactive distillation of a biocrude oil, the method comprising:

providing a biocrude formed by heat treating a carbonaceous feed comprising biomass;

providing an additive capable of reacting with, catalyzing and/or inhibiting a reaction involving the biological crude oil and/or solubilizing the biological crude oil and/or a reaction product thereof;

mixing the bio-crude oil and the additive to form a feed mixture;

heating the feed mixture at elevated pressure; and

reducing the partial pressure of a substance originally present in the raw bio-oil and formed from the reaction of the raw bio-oil such that the substance distills to form a different fraction.

3. The process according to claim 1 or 2, wherein the raw bio-oil is heated under elevated pressure generated by the vapour of the raw bio-oil itself.

4. The method of claim 1 or 2, wherein the raw bio-oil is heated under elevated pressure generated by a pressurized fluid surrounding the raw bio-oil.

5. The method of claim 1 or 2, wherein the raw bio-oil is heated at an elevated pressure created by a combination of a pressurized fluid and a confined space that delays volatilization of components from the raw bio-oil.

6. The method according to any of the preceding claims 1-5, wherein the total system pressure is lowered such that the partial pressure of all substances originally present in and/or derived from the raw bio-oil is reduced.

7. The process according to any one of the preceding claims 1-5, wherein a further fluid is mixed with the hot raw bio-oil and its reaction products, so as to reduce the partial pressure of all substances originally present in and/or derived from the raw bio-oil.

8. The method of claim 7, wherein the fluid reacts with the biocrude oil.

9. The process according to any one of the preceding claims, wherein one or more heavier fractions are further thermally treated to produce additional lighter products.

10. The process of any one of the preceding claims, wherein the process further comprises hydrotreating one or more of the fractions formed by distillation with a hydrogenation agent to produce a hydrotreated product.

11. The process of claim 10, wherein the hydrogenation reagent is hydrogen.

12. The method of claim 10 or 11, wherein hydrogen is used as a pressurized fluid around the biomeal to produce an elevated pressure.

13. The process according to any one of claims 10 to 12, wherein hydrogen is mixed with the hot raw bio-oil and its reaction products so as to reduce the partial pressure of all substances originally present in and/or derived from the raw bio-oil.

14. The process according to any one of claims 10 to 13, wherein the bio-crude vapor fraction to be hydrotreated is rapidly heated to a hydrotreating reaction temperature in the presence of a hydrotreating catalyst.

15. The process according to any one of claims 10 to 14, wherein the lighter fraction and the heavier fraction are separated in a respective hydrotreating reactor hydrotreating at least one separated fraction, wherein the initial section of the hydrotreating reactor is subjected to a separation function.

16. The process of any one of claims 1 to 8, wherein the process further comprises reforming one or more of the fractions formed by distillation to produce a reformed product.

17. The method of claim 16, wherein the fraction is reformed with any one of steam, air, oxygen, carbon dioxide, hydrogen, or a mixture containing any two or more thereof.

18. The method of any one of the preceding claims, wherein the bio-crude oil is bio-oil from pyrolysis of a carbonaceous feed comprising biomass.

19. The method of any one of the preceding claims 1 to 17, wherein the biological crude oil is a product from hydrothermal liquefaction of a carbonaceous feed comprising biomass.

20. A system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of a component in the product mixture such that volatile materials in the product mixture evaporate to form one or more condensed and vapor phases.

21. A system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a mixture comprising a biomeal oil formed by heat treatment of a carbonaceous feed comprising biomass and an additive into a distillation reactor that can be pressurized;

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of a component in the product mixture such that volatile materials in the product mixture evaporate to form one or more condensed and vapor phases.

22. A system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

at least one further inlet for feeding an additive into the distillation reactor;

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of a component in the product mixture such that volatile materials in the product mixture evaporate to form one or more condensed and vapor phases.

23. The system of any one of claims 20 to 22, wherein the distillation reactor is a coil or series of coils.

24. The system of any one of claims 20 to 23, wherein the distillation reactor is immersed in a heating medium.

25. The system of claim 24, wherein the heating medium is a fluid in which the distillation reactor is immersed.

26. The system of claim 24, wherein the heating medium is a bath of fluidized sand in which the distillation reactor is immersed.

27. The system of any one of claims 20 to 26, wherein the partial pressure of a component in the product mixture is reduced using a pressure let down valve or an orifice through which the product stream flows in a controllable manner.

28. The system of any one of claims 20 to 26, wherein an additional fluid is introduced that mixes with and dilutes the product mixture to reduce the partial pressure of components in the product mixture.

29. The system of claim 28, wherein the additional fluid is a gas.

30. The system of any one of claims 20 to 29, wherein the evaporation vessel is a coil or series of coils.

31. The system of any one of claims 20 to 26 or 28 to 30, wherein the distillation reactor and the vaporization vessel are the same vessel.

32. The system of any one of claims 20 to 31, wherein the system further comprises means for cooling and condensing the volatile phase into more than one fraction.

33. The system of any one of claims 21 to 32, wherein the additive is capable of reacting with, catalyzing and/or inhibiting a reaction involving the biological crude oil and/or solubilizing the biological crude oil and/or a reaction product thereof.

34. The system of any one of claims 20 to 33, wherein the system further comprises one or more reactors into which one or more heavier fractions are fed for thermal treatment to produce additional lighter products.

35. The system of any one of claims 20 to 34, wherein the bio-crude is a bio-oil from pyrolysis of a carbonaceous feed comprising biomass.

36. The system of any one of claims 20 to 34, wherein the bio-crude is a product from hydrothermal liquefaction of a carbonaceous feed comprising biomass.

37. A system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to a hydrotreating reactor containing a hydrotreating catalyst for hydrotreating therein to form a hydrotreated product, and

the hydrotreating reactor has means for receiving at least one hydrotreating agent and at least one outlet for discharging the hydrotreated product and unconverted hydrotreating reactant.

38. A system for reactive distillation of a biocrude oil, the system comprising:

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to a hydrotreating reactor containing a hydrotreating catalyst for hydrotreating therein to form a hydrotreated product, and

the hydrotreating reactor has means for receiving at least one hydrotreating agent and at least one outlet for discharging the hydrotreated product and unconverted hydrotreating reactant.

39. A system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

at least one further inlet for feeding an additive into the distillation reactor;

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to a hydrotreating reactor containing a hydrotreating catalyst for hydrotreating therein to form a hydrotreated product, and

the hydrotreating reactor has means for receiving at least one hydrotreating agent and at least one outlet for discharging the hydrotreated product and unconverted hydrotreating reactant.

40. The system of any one of claims 37 to 39, wherein the system further comprises at least one means to heat the fraction in the hydrotreating reactor only when the fraction contacts a hydrotreating catalyst that has been heated to a hydrotreating reaction temperature at which the catalyst is capable of providing activated hydrogen for a hydrotreating reaction to occur.

41. The system of claim 40, wherein the fraction to be hydrotreated is heated by mixing the fraction with a hot stream of the hydrogenating reagent.

42. The system of any one of claims 37 to 41, wherein the means for receiving the hydrogenation reagent into the hydrotreating reactor is the same inlet for the fraction to be hydrotreated, wherein the fraction and the hydrogenation reagent are rapidly mixed.

43. The system of any one of claims 37 to 41, wherein the means for receiving the hydrogenation reagent into the hydrotreating reactor is different from an inlet for the fraction to be hydrotreated.

44. A system according to any one of claims 38 to 43, wherein the additive, being a single compound or mixture, performs any or all of the following functions: reacting with the raw bio-oil, catalyzing and/or suppressing a reaction of the raw bio-oil, dissolving the raw bio-oil and/or reaction products thereof during distillation or participating in the hydrotreating reaction during the hydrotreating.

45. The system of any one of claims 37 to 44, wherein reducing the partial pressure of a component in the product mixture is achieved with any one or combination of a pressure let down valve and introduction of additional fluid.

46. The system of claim 45, wherein the additional fluid is the hydrogenation reagent.

47. The system of any one of claims 37 to 46, wherein the system further comprises one or more reactors in which one or more heavier fractions are further thermally treated to produce additional lighter products.

48. The system of any one of claims 37 to 47, further comprising one or more hydrotreating reactors for hydrotreating other fractions formed during distillation or thermal treatment.

49. The system of any one of claims 37 to 48, wherein the hydrogenation reagent comprises one or more H donating compounds capable of providing activated hydrogen in the hydrotreating reactor.

50. The system of any one of claims 37 to 49, wherein the hydrogenation reagent comprises one or more compounds capable of generating free radicals to stabilize broken bonds in the hydrotreating reactor.

51. The system of any one of claims 37 to 50, wherein the hydrogenation reagent comprises the hydrotreated product.

52. The system of any one of claims 37 to 51, wherein the hydrogenation reagent comprises hydrogen gas.

53. The system according to any one of claims 37 to 52, wherein the lighter fraction and the heavier fraction are separated in respective hydrotreating reactors hydrotreating at least one separated fraction, wherein an initial section of the hydrotreating reactors performs the separation function.

54. The system of any one of claims 37 to 53, wherein there is more than one hydrotreating reactor in series.

55. The system of any one of claims 37 to 54, wherein each hydrotreating reactor has a biological crude oil fraction feed resulting from reactive distillation of the biological crude oil.

56. The system of any one of claims 37 to 55, wherein the hydrogenation reagent for the second or any downstream hydrotreating reactor comprises a product stream from a preceding hydrotreating reactor.

57. The system of any one of claims 37-53, wherein the bio-crude is a bio-oil from pyrolysis of a carbonaceous feed comprising biomass.

58. The system of any one of claims 37 to 53, wherein the biological crude oil is a product from hydrothermal liquefaction of a carbonaceous feed comprising biomass.

59. A system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to be reformed into a reforming reactor for reforming therein to form a reformed product gas; and

a reforming reactor having at least one inlet for receiving at least one reforming agent and at least one outlet for discharging reformate and unconverted reforming reactant.

60. A system for reactive distillation of a biocrude oil, the system comprising:

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to be reformed into a reforming reactor for reforming therein to form a reformed product gas; and

a reforming reactor having at least one inlet for receiving at least one reforming agent and at least one outlet for discharging reformate and unconverted reforming reactant.

61. A system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

at least one further inlet for feeding an additive into the distillation reactor;

a heat source and means for heating the biocrude oil at elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter an evaporation vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to be reformed into a reforming reactor for reforming therein to form a reformed product gas; and

a reforming reactor having at least one inlet for receiving at least one reforming agent and at least one outlet for discharging reformate and unconverted reforming reactant.

62. The system of any one of claims 60 or 61, wherein the additive, being a single compound or a mixture, performs any or all of the following functions: reacting with the biological crude oil, catalyzing and/or suppressing a reaction of the biological crude oil, dissolving the biological crude oil and/or reaction products thereof during distillation or participating in a reforming reaction during the reforming.

63. The system of any one of claims 59 to 62, wherein reducing the partial pressure of a component in the product mixture is achieved with any one or combination of a pressure let down valve and introduction of additional fluid.

64. The system of claim 63, wherein the additional fluid is the reforming agent.

65. The system of any one of claims 59 to 64, wherein the additional fluid is steam.

66. The system of any one of claims 59 to 65, wherein the reforming agent is H₂O (steam), CO₂Air, oxygen or H₂One or more of (a).

67. The system of any one of claims 59 to 66, wherein the system further comprises one or more reforming reactors for reforming other fractions formed during distillation.

68. The system of any one of claims 59 to 67, wherein one or more of the reforming reactors operate as a combustion reactor.

69. The system of any one of claims 59 to 68, wherein reformate from any or all reforming or combustion reactors is further subjected to cleaning using coke or coke-loaded catalyst.

70. The system of claim 69, wherein the reformate is cleaned in a two-stage process in which a first stage containing coke or coke-laden catalyst reforms a tarry material, destroying impurities such as NH₃HCN and H₂S and removing any large particles and a second stage containing a porous medium cools the reformate, recovers heat energy and rejects the remaining organic impuritiesThe impurities condense on the porous media.

71. The system of claim 70, wherein the porous media comprises coke or a coke-containing adsorbent.

Technical Field

The present invention relates to a method and system for reactive distillation of bio-crude oil, in particular bio-oil at elevated pressure. The invention also relates to the integration of reactive distillation of the raw bio-oil with further upgrading/utilization of the raw bio-oil.

Background

Biomass is the only carbon-containing renewable resource that can be directly used to produce liquid fuels, chemicals, and carbon materials. Among the various pathways for biomass conversion, thermochemical conversion offers many advantages from the standpoint of process yield and efficiency. Pyrolysis and hydrothermal liquefaction of biomass have attracted considerable global attention, particularly for the production of liquid fuels and chemicals.

Pyrolysis of biomass will produce three major classes of products, including liquid products known as bio-oil, solid products known as biochar, and gaseous products including various flammable and non-flammable gases. There are many different pyrolysis technologies and one such technology is the mill pyrolysis of biomass disclosed in PCT/AU 2011/000741. Bio-oils are a class of bio-crude oils and can be biorefined/upgraded into various liquid fuels and chemicals (e.g., using the techniques disclosed in PCT/AU 2013/000825) and solid carbon materials (e.g., using the techniques disclosed in PCT/AU 2016/000133).

When biomass is heated to elevated temperatures, bio-oil has very complex physical and chemical structural characteristics as a product from (partial) fragmentation of biopolymers and other substances in the biomass. For example, the substances in bio-oil can have a very wide range of molecular mass distributions, ranging from small molecules, such as water, to partially degraded biopolymers of cellulose, hemicellulose, and lignin. The materials in the bio-oil can have a variety of chemical structures including, but not limited to, aliphatic, cycloaliphatic, hydroaromatic, heteroaromatic and aromatic structures having abundant functional groups such as carboxylic acid groups, carbonyl groups and phenolic groups. Although oxygen-containing structures (e.g., furan-type structures) and functional groups are very abundant in bio-oils, various organic structures containing nitrogen and/or sulfur may also be present in bio-oils. Therefore, bio-oils are very reactive. Various inorganic substances, such as potassium, sodium, magnesium, calcium and various trace elements, which are macro-and micro-inorganic nutrients for the growth of biomass, may also partially volatilize during pyrolysis and become part of the bio-oil.

Although bio-oils are commonly referred to as liquids, bio-oils may also have colloidal structures and properties.

Biochar fines and other particulates (e.g., soil from biomass feed for pyrolysis) may also be present in the bio-oil.

Biological crude oil from hydrothermal liquefaction of biomass or other means of thermochemical conversion of biomass all have many of the characteristics of biological oil described above.

In developing new technologies for upgrading or directly utilizing bio-crude oil, the complex properties and structural features of bio-crude oil must be fully considered. For example, when bio-oils are hydrotreated to produce liquid fuels and chemicals, the lighter materials in bio-oils may have very different behavior than the corresponding heavier materials. Ideally, they should be hydrotreated under very different conditions.

Similarly, the lighter fraction and the heavier fraction are significantly different during reforming and have different optimal reforming conditions.

In addition, heavier materials may also have different beneficial uses than lighter materials. For example, heavier materials may be more suitable as a feed for producing solid carbon materials than lighter materials.

Still further, the inorganics or particulates in the bio-oil may adversely affect the optimum performance of the bio-oil upgrading or utilization process and should be separated from the bio-oil prior to upgrading or utilization of the bio-oil.

Therefore, there is a need to separate bio-oil into various fractions, for example based on their volatility or boiling point (more practical boiling point range), simultaneously with the removal of inorganic matter and particulates. Distillation seems to be a suitable way to perform such separation. However, due to the high reactivity of bio-oil, excessive coke formation is a major problem when bio-oil is distilled at ambient or reduced (vacuum distillation) pressure using prior art techniques. New techniques for separating biological crude oil, for example by distillation, into fractions and minimizing coke formation are necessary.

Disclosure of Invention

According to a first aspect of the present invention there is provided a process for the reactive distillation of a biocrude oil, the process comprising:

providing a biocrude formed by heat treating a carbonaceous feed comprising biomass;

heating the raw bio-oil at an elevated pressure; and

the partial pressure of the species initially present in the biocrude and formed from the reaction of the biocrude is reduced so that the species distills to form different fractions.

As used herein, the term "biomass" refers to any material derived from a living or recently living organism, including materials excreted from or by the organism. Examples include, but are not limited to, lignocellulosic materials derived from plants and manure from animals.

As used herein, the term "carbonaceous feed" is intended to include a variety of carbonaceous renewable and non-renewable feeds, including, but not limited to, coal (its full coalification grade spectrum), biomass, solid waste, or mixtures thereof. The solid waste may include, but is not limited to, agricultural waste, forestry waste, industrial waste, domestic/municipal waste, or residues from the processing of carbonaceous feedstocks. These wastes may also be mixed into a carbonaceous feed. In fact, in a broad sense, many solid wastes are considered biomass. Alternatively, biomass is at least an important component of many solid wastes.

As used herein, the term "heat treatment" is intended to include within its scope any process at elevated temperatures in the presence or absence of additional substances. For example, pyrolysis of biomass in an inert, oxidizing, or reducing atmosphere is a thermal treatment process. Hydrothermal treatment of biomass in water (in subcritical or supercritical state or at critical point) is another type of heat treatment process.

As used herein, the term "biological crude oil" is intended to include any liquid or pasty/slurry product from the thermal treatment of biomass or other carbonaceous feedstock. Bio-oil from the pyrolysis of biomass is a typical bio-crude oil. The bio-crude may include various impurities including, but not limited to, dissolved minerals and particulates. The particulates may contain organic carbon (e.g., biochar fines) or may be common organics (e.g., soil in the feed including biomass that is ultimately in bio-crude).

In an embodiment, the bio-crude oil is bio-oil from pyrolysis of a carbonaceous feed comprising biomass. In a further particular embodiment, the bio-crude oil is a bio-oil from pyrolysis of biomass. In another embodiment, the biological crude oil is a product from hydrothermal liquefaction of a carbonaceous feed comprising biomass or a product from hydrothermal liquefaction of biomass.

The term "elevated pressure" refers to a pressure level that is higher than ambient pressure. Similarly, the term "elevated temperature" refers to a temperature level that is higher than ambient temperature.

As used herein, the term "distillation" is intended to include within its scope any process in which components (or species) in a feed for distillation are separated into various fractions having different boiling point ranges or other properties. The boiling point ranges for the various fractions may overlap with one another. After separation, these fractions may be in the form of vapor (gas), supercritical fluid, liquid, solid, or mixtures thereof, such as pastes, slurries, and composites. As used herein, the term "reactive distillation" is intended to include any distillation process in which at least one type of chemical reaction occurs.

Distillation of the biocrude oil typically involves chemical reactions due to the high reactivity of the biocrude oil. Therefore, distillation of the biocrude oil is typically a reactive distillation process. Indeed, even if stored under ambient conditions, bio-oils, although slow, can undergo complex chemical reactions. In particular, heating the raw bio-oil to an elevated temperature may cause a network of chemical reactions to occur in the raw bio-oil, forming lighter and heavier materials. For example, distillation of bio-oil to temperatures above 150 ℃ at pressures near atmospheric can result in the formation of smoke and solid residues as a result of the reactions taking place.

Embodiments of the present invention have significant advantages. In particular, heating the raw bio-oil (e.g., bio-oil) under pressure greatly reduces the formation of coke or heavy matter as compared to heating the same raw bio-oil to the same temperature at a lower pressure, such as at atmospheric pressure or reduced pressure (under vacuum).

Without being bound by any particular theory, various benefits may be realized by heating the biomeal oil at elevated pressures. For example, many chemicals in bio-oils are polar, primarily due to the presence of various oxygen-containing structures in bio-oils. Water, which often occupies 15 to 35 wt% of the bio-oil, plays an important role in dissolving various substances in the bio-oil, helping to keep the bio-oil as a liquid or liquid-like material. Interactions between water and other bio-oil components include not only van der waals forces but also other interactions such as H-bonds. These forces are also at least partially responsible for the 3-D structural configuration of macromolecules in the bio-oil. Other light materials in the bio-oil also contribute to the dissolution of heavy materials in the same bio-oil. When the bio-oil is heated at low pressure, e.g., near atmospheric pressure or under a certain degree of vacuum, water and some light materials in the bio-oil will readily evaporate, leaving behind a viscous liquid or solid. However, when the bio-oil is heated at elevated pressure, evaporation of water and light materials will be greatly impeded or inhibited. The presence of water and light materials will also dilute the heavy materials, helping to slow down the recombination reactions responsible for the formation of additional heavier materials. Many other reactions can also be carried out at elevated pressures. For example, acids in the bio-oil (e.g., formic acid and acetic acid) may catalyze hydrolysis reactions that will help reduce the formation of heavies. In contrast, during distillation at low pressure, evaporation of water and light acids will make these reactions, such as hydrolysis, very difficult or impossible.

The saturated vapor pressure of a material (including mixtures) is a function of temperature. With embodiments of the present invention, it is difficult to set a fixed pressure value for reactive distillation of the biomeal oil. The higher the pressure, the less amount of the biocrude component will be vaporized. The distillation pressure to which the biomeal oil is heated may advantageously be maintained at a level higher than the saturated vapor of biomeal oil at any temperature to which the biomeal oil is heated.

The step of heating the raw bio-oil under elevated pressure may be performed in various ways. In one embodiment, the raw bio-oil is heated under elevated pressure generated by the vapors of the raw bio-oil itself. For example, the raw bio-oil may be heated at elevated pressure by limiting the space available for volatilization and escape of vapors from the heated raw bio-oil in a closed vessel (autoclave).

In another embodiment, the biomeal oil is heated at an elevated pressure generated by a pressurized fluid surrounding the biomeal oil but having low solubility in the biomeal oil liquid. The fluid may be an inert gas or other gas, including mixtures thereof.

In further embodiments, the biomeal oil is heated at an elevated pressure created by a combination of a pressurized fluid and a confined space that delays the volatilization of components from the biomeal oil.

When the reactive distillation of the raw bio-oil is integrated with other means of upgrading/utilizing the raw bio-oil, it is contemplated to set the distillation pressure at a higher or close level than the upgrading/utilizing process. For example, when the reactive distillation is integrated with hydrotreating of a biological crude oil (see below for more details), the distillation may be performed at a pressure higher or close to the pressure of hydrotreating.

The peak temperature of the biological crude oil being distilled is an important factor in affecting the degree of separation that will be achieved from the reactive distillation. This can be selected and set according to the desired product to be obtained from the distillation. In a particular embodiment, in order to achieve a good yield of light substances from the bio-oil, the peak temperature for distillation of the bio-oil is set at a level preferably between 100 ℃ and 300 ℃, more preferably between 150 ℃ and 270 ℃, even more preferably between 150 ℃ and 230 ℃ and most preferably between 150 ℃ and 210 ℃ when the operating pressure is about 7 MPa.

The choice of peak temperature is based on the volatility of the substances present in the biological crude oil to be distilled and on the extent of the reaction to be achieved. In one embodiment, the peak temperature is set low (<150 ℃) in order to minimize chemical reactions. Only very light materials will be distilled from the bio-crude. In another embodiment, the peak temperature is set at a moderate level (e.g., <230 ℃) for some very reactive species to be reacted. In yet another embodiment, the peak temperature is set high (e.g., up to 450 °) so that the biomeal crude oil undergoes strong reactions, including but not limited to cracking and polymerization reactions, so that a strong solid residue is formed and the remaining portion of biomeal crude oil is distilled out.

Once the bio-crude reaches the desired peak temperature, the partial pressure of the species originally present in and/or derived from the bio-crude can be reduced to allow distillation to proceed. This can be achieved in many ways. In one embodiment, the overall system pressure is reduced such that the partial pressure of all species originally present in and/or derived from the biocrude oil is reduced. This is usually accompanied by a reduction in temperature, which may require a device to supply the thermal energy required for the evaporation (latent heat) of the volatile substance.

In another embodiment, the further fluid is mixed with the hot raw bio-oil and its reaction products in such a way that the partial pressure of all substances originally present in and/or derived from the raw bio-oil is reduced. The exact choice of fluid will depend on the purpose of the reactive distillation. In one aspect, the fluid is preferably a gas and more preferably an inert gas. On the other hand, the reactive fluid preferably undergoes some beneficial reaction with the biocrude component. Furthermore, evaporation of volatile substances may cause the system temperature to drop, and thus a means of supplying heat to satisfy the heat of evaporation may be required.

The volatilized materials may condense into various fractions having different boiling point ranges, but the boiling point ranges of these fractions may overlap with each other. In one embodiment, the condensation may be carried out in multiple steps/stages, as in conventional distillation columns known to those skilled in the art. In an alternative embodiment, the condensable volatiles may be condensed into a distillate. The product fraction may be gaseous (vapor), liquid, solid or mixtures/composites thereof, such as slurries and pastes. For example, due to reactions occurring during distillation, lighter materials may be formed and thus some products, as part of the distillation, may be containing such materials as CO₂And CH₄In gaseous (vapor) form.

According to a second aspect of the present invention there is provided a process for the reactive distillation of a biocrude oil, the process comprising:

providing a biocrude formed by heat treating a carbonaceous feed comprising biomass;

providing an additive capable of reacting with the raw bio-oil, catalyzing and/or inhibiting a reaction involving the raw bio-oil and/or solubilizing the raw bio-oil and/or its reaction products;

mixing the bio-crude oil and the additive to form a feed mixture;

heating the feed mixture at elevated pressure; and

the partial pressure of the species initially present in the biocrude and formed from the reaction of the biocrude is reduced so that the species distills to form different fractions.

Although "catalysis" generally means the action of accelerating a reaction, it also broadly includes the action of slowing the reaction, i.e., "inhibiting" the reaction. In the same reaction mixture, the same catalyst may catalyze some reactions and suppress others.

One purpose of introducing the additive in the second aspect of the invention compared to the first aspect of the invention is to allow the raw bio-oil to react with the additive when the feed mixture is heated, either by catalysing/initiating a new reaction between the raw bio-oils or by catalysing/suppressing an inherent reaction involving the raw bio-oil components at elevated temperatures. The additive may also perform the function of catalyzing/initiating new reactions and catalyzing/suppressing intrinsic reactions involving the biological crude oil component.

In one embodiment, the additive is methanol for reactive distillation of bio-oil from pyrolysis of biomass. Methanol can be in the form of a liquid (subcritical state), a vapor, a supercritical fluid, or at its critical point. Methanol can initiate many reactions with bio-oil components. For example, methanol can react with carboxylic acid groups in the bio-oil to form esters, with carbonyl groups (e.g., aldehydes) in the bio-oil to form acetals, and with sugars (or oligomers) in the bio-oil to form products such as levulinic acid. Transesterification with methanol may also occur. Many other reactions may also occur, such as methanolysis of olefins. Methanol may also at least partially inhibit reactions associated with bio-oil that would form heavy materials or coke. These reactions between methanol and bio-oil components will help stabilize the bio-oil and reduce coke formation when the bio-oil is heated. Many of the reactions associated with methanol and bio-oil can be catalyzed by acidic components in the bio-oil or externally added acidic species.

In another embodiment, higher alcohols (e.g., ethanol, propanol, and butanol, or any mixture thereof) are used as additives.

The additives may also be mixtures. In a further embodiment, a mixture of alcohols including methanol and/or higher alcohols is used as an additive.

In a particular embodiment, the additive mixture is a mixture of an alcohol (or alcohol mixture) and an acid, wherein the acid will act as a catalyst for the reaction between the alcohol and the bio-oil. In an alternative particular embodiment, the additive mixture is a mixture of an alcohol (or alcohol mixture) and a base, wherein the base will catalyze the reaction between the alcohol and the bio-oil.

Those skilled in the art will recognize that many different types of additives, catalysts, or mixtures thereof may be used to initiate/catalyze new reactions in the raw bio-oil and/or inhibit inherent reactions of the raw bio-oil at elevated temperatures and pressures without departing from the inventive nature of the present invention.

Another purpose of introducing the additive is for the additive to act as a solvent or as part of a solvent mixture. In particular, the additive is primarily used to dissolve heavy matter in the biological crude oil and/or heavy matter formed from the biological crude oil when heated. This is particularly useful for preventing the distillation system from becoming clogged or reducing the extent and/or frequency of clogging. In a particular embodiment, the additive is acetone. During heating of the feed mixture, the acetone may be in the form of a liquid or supercritical fluid or at its critical point, depending on the conditions of the reactive distillation. One skilled in the art will recognize that many types of solvents may be used for this purpose by taking into account the thermal stability, solubility of the heavies, and other factors such as economics. Solubility herein refers to under the conditions of distillation (temperature and pressure) and not necessarily under ambient conditions. Recovery of the solvent after distillation and, therefore, reuse of the solvent are also contemplated.

In an embodiment of the first or second aspect of the invention, one or more heavier fractions are further heat treated to produce additional lighter products.

In another embodiment of the first or second aspect of the present invention, one or more heavier fractions are used as fuel. In a further embodiment, these heavier fractions are blended with additional substances to modify their properties, such as viscosity.

There is also a need to integrate such bio-oil separation processes into an overall bio-oil upgrading or utilization process for optimal performance and efficiency. For example and without limiting the scope of the invention, for biological crude oil to be hydrotreated, the biological crude oil must be heated to an elevated temperature at which the hydrotreating reaction takes place, which requires a large amount of energy. The presence of water in the bio-crude (e.g., water in the bio-oil) means that in many hydrotreating processes, in addition to evaporating the bio-crude material, a large amount of energy may be required to evaporate the water. It may be very advantageous to separate and remove very heavy materials, inorganics and particulates from the bio-crude prior to hydrotreating. Therefore, there is a need for innovations to distill the biocrude with minimized coke formation and integrate the distillation into the overall biocrude upgrading or utilization process. The integration of the distillation of the biomeal oil with the hydrotreating of the biomeal oil is one such example. Integration of bio-crude distillation with bio-crude reforming is another such example.

According to a third aspect of the present invention there is provided a process for the reactive distillation of a biocrude oil, the process comprising:

providing a biocrude formed by heat treating a carbonaceous feed comprising biomass;

heating the raw bio-oil at an elevated pressure;

reducing the partial pressure of species initially present in the biocrude and formed from the reaction of the biocrude such that the species distills to form different fractions; and

hydrotreating one or more of the fractions with a hydrogenation agent to produce a hydrotreated product.

The term "hydrotreating" or variations such as "hydrotreating" and "hydrotreating" as used herein refers to any reaction between a biological crude oil and a hydrogenating agent, including but not limited to hydrogenation, hydrocracking, hydrodeoxygenation, hydrodesulfurization, and hydrodenitrogenation. These reactions may be catalytic or non-catalytic.

According to a fourth aspect of the present invention there is provided a process for the reactive distillation of a biocrude oil, the process comprising:

providing a biocrude formed by heat treating a carbonaceous feed comprising biomass;

providing an additive capable of reacting with the bio-crude;

mixing the bio-crude oil and the additive to form a feed mixture;

heating the feed mixture at elevated pressure; and

reducing the partial pressure of species initially present in the biocrude and formed from the reaction of the biocrude such that the species distills to form different fractions; and

hydrotreating the one or more fractions to produce a hydrotreated product.

In one embodiment of both the third and fourth aspects of the invention, the hydrogenation reagent is hydrogen.

In contrast to the first and second aspects of the invention, respectively, the third and fourth aspects of the invention introduce a further step of hydrotreating one or more fractions from the reactive distillation of a biological crude oil. Embodiments of the present invention provide an advantageous integration of reactive distillation with upgrading of biological crude oil, with hydrotreating being an example of an upgrading process. This may have significant advantages over direct upgrading (hydrotreating) of the bio-crude, which will be explained below using bio-oil as an example of bio-crude:

(a) in a preferred embodiment, hydrogen for hydrotreating may be used as a fluid to reduce the partial pressure of species originally present in and/or derived from the bio-crude oil to effect distillation.

(b) Bio-oils may contain inorganic substances (e.g. K, Mg and Ca salts or carboxylates) and particulates (including bio-carbon fines). These minerals and particulates can adversely affect the hydrotreating process, for example by plugging or poisoning the catalyst bed. These minerals and particulates have very limited volatility and can be effectively separated from the bio-oil during reactive distillation of the bio-oil. In a preferred embodiment, the hydrotreating of the organic components of the bio-oil is carried out without the side effects of these organics and particulates.

(c) Heavy and light materials of the bio-oil can be distilled into different fractions and hydrotreated under their optimal hydrotreating conditions, respectively. In one embodiment, the bio-oil is distilled into two fractions: the heavier fraction includes very heavy organics, inorganics and particulates, and the lighter fraction contains the lighter material of the bio-oil. The lighter fraction may be hydrotreated under conditions very different from those used for the heavy fraction. In an alternative embodiment, only the lighter fraction is hydrotreated, the heavier fraction being recovered for other purposes.

(d) In a preferred embodiment, the fraction to be hydrotreated is fed directly, in its vapour form, to the hydrotreating reactor without condensation. This means that the heat required to heat the bio-oil and to vaporize the water and organics can be supplied during reactive distillation, reducing the heat requirement at the inlet of the hydrotreating reactor, allowing the flash heating of the bio-crude oil vapour fraction to be hydrotreated according to the hydrotreating technique disclosed in PCT/AU2013/000825 to the hydrotreating reaction temperature in the presence of a hydrotreating catalyst, minimizing coke formation.

(e) In embodiments, an alcohol (e.g., methanol) is added to the bio-oil during distillation. The alcohol reacts efficiently with many reactive functional groups in the bio-oil to stabilize the bio-oil. Stabilization of the bio-oil helps to reduce coke formation during hydrotreating.

(f) In a further embodiment, the reactive distillation may be further integrated with the hydrotreating. As an example, the lighter fraction and the heavier fraction are separated in a respective hydrotreating reactor hydrotreating at least one of the separated fractions, wherein the initial section of the hydrotreating reactor performs the separation function.

In an embodiment of the third or fourth aspect of the invention, the system further comprises one or more reactors wherein the one or more heavier fractions are further thermally treated to produce additional lighter products which are further hydrotreated.

According to a fifth aspect of the present invention there is provided a process for the reactive distillation of a biomeal oil, the process comprising:

providing a biocrude formed by heat treating a carbonaceous feed comprising biomass;

heating the raw bio-oil at an elevated pressure;

reducing the partial pressure of species initially present in the biocrude and formed from the reaction of the biocrude such that the species distills to form different fractions; and

reforming one or more fractions to produce a reformed product.

As used herein, the term "reforming" refers to the conversion of biological crude oil or fractions thereof, by reaction thereof with a reforming agent, into lighter products, typically gasesReaction of the substances. Mainly comprising CO and H₂The synthesis gas of (a) is typically the target product. The reforming agent can be steam, air, oxygen, carbon dioxide, hydrogen, or a mixture containing any two or more thereof.

According to a sixth aspect of the present invention there is provided a method of reactive distillation of a biocrude oil, the method comprising:

providing a biocrude formed by heat treating a carbonaceous feed comprising biomass;

providing an additive capable of reacting with the bio-crude;

mixing the bio-crude oil and the additive to form a feed mixture;

heating the feed mixture at elevated pressure; and

reducing the partial pressure of species initially present in the biocrude and formed from the reaction of the biocrude such that the species distills to form different fractions; and

reforming one or more fractions to produce a reformed product.

By removing inorganic, particulate and very heavy materials via reactive distillation of the bio-crude, a number of beneficial results can be achieved during reforming, including reduced coke formation, reduced poisoning of the catalyst (if used in a catalytic reforming process) and reduced plugging of the catalyst bed, as well as increased product quality.

The third to sixth aspects of the invention serve merely as examples of integration of reactive distillation with further upgrading or utilization of the bio-crude. In addition to the hydrotreatment and reforming exemplified in the third to sixth aspects of the invention, the reactive distillation of the invention can be integrated with many other ways of bio-crude upgrading and utilization, which will be within the scope of the invention.

According to a seventh aspect of the present invention there is provided a system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture such that volatile materials in the product mixture evaporate to form one or more condensed and vapor phases.

The distillation reactor may take various shapes. In one embodiment, the distillation reactor is a coil or series of coils. The coil or series of coils is advantageous from the standpoint of providing a large amount of heat transfer area to heat the biocrude oil at elevated pressure inside the distillation reactor.

Heat may be provided to the distillation reactor in various ways. In one embodiment, the coil or series of coils is immersed in a heating medium. In one embodiment, the heating medium may be a fluid in which a distillation reactor (e.g., a coil or series of coils) is immersed, such as in a heat exchanger. In another embodiment, the heating medium is a bed (bath) of fluidized sand in which a distillation reactor (e.g., a coil or series of coils) is immersed.

In one embodiment, the partial pressure of the components in the product mixture is reduced using a pressure let down valve or orifice through which the product flows in a controlled manner. The degree of pressure reduction is controlled by the amount the bleed valve is opened or the size of the orifice. In a particular embodiment, a pressure let down valve or orifice is installed between the distillation reactor and the vaporization vessel.

In another embodiment, additional fluid is introduced, the additional fluid mixes with the product mixture and dilutes the product mixture to reduce the partial pressure of the components in the product mixture. In this case, the system further comprises a further inlet and/or a mixer. In a particular embodiment, the further fluid is a gas.

Upon reducing the partial pressure of the components in the product mixture, the volatile compounds will evaporate in the evaporation vessel. Evaporation is typically an endothermic process. It is advantageous to supply heat to the evaporation vessel. The vaporization container may take various shapes. In one embodiment, the vaporization vessel is a coil or series of coils. The coil or series of coils advantageously provides a large heat transfer surface area to supply heat to the vaporization vessel. The amount of heat to be supplied will depend on the degree of separation to be achieved. Higher vaporization vessel temperatures will tend to vaporize more of the component than lower vaporization vessel temperatures.

In a further embodiment, the distillation reactor and the evaporation vessel are the same vessel. In this case, the distillation reactor may not have a separate physical outlet. In a particular embodiment in which the distillation reactor is a coil, additional fluid is introduced into the coil at a point downstream of the inlet to the coil. The introduction of the additional fluid divides the coil into two parts: the first portion of the coil serves as a distillation reactor and the second portion serves as an evaporation vessel. There may be more than one such point to introduce additional fluid.

In some applications, it may be sufficient to distill the biomeal oil into a condensed phase and a vapor phase in the vaporization vessel. Of course, the system may further comprise means for cooling and condensing the volatile phase. In other applications, it may be necessary to produce a fraction having a narrower boiling point range (when condensed) than the volatile phase initially produced in the evaporation vessel. For this reason, the system further comprises means for cooling and condensing the volatile phase into more than one fraction. In a particular embodiment, the volatile phase initially formed undergoes a gradual cooling and condensation for collecting the condensate into different fractions having different boiling point ranges. Those skilled in the art of distillation will recognize that various means, such as distillation columns, and corresponding cooling means, may be used for this purpose. These also include corresponding means to achieve a backflow to improve the separation efficiency.

According to an eighth aspect of the present invention there is provided a system for reactive distillation of a biocrude oil, the system comprising:

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture such that volatile materials in the product mixture evaporate to form one or more condensed and vapor phases.

According to a ninth aspect of the present invention there is provided a system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

at least one further inlet for feeding an additive into the distillation reactor;

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture such that volatile materials in the product mixture evaporate to form one or more condensed and vapor phases.

The eighth and ninth aspects of the present invention differ from the seventh aspect primarily in that the additive is fed to the distillation reactor. The additive may perform any or all of the following functions:

(a) initiating and participating in a new reaction of components in the raw bio-oil when the raw bio-oil is heated in the distillation reactor at an elevated pressure,

(b) catalyzing and/or suppressing an intrinsic reaction associated with the bio-crude oil when the bio-crude oil is heated at an elevated pressure in the distillation reactor, and/or

(c) Dissolving (acting as a solvent) heavy matter present in and/or formed from components in the bio-crude in the distillation reactor.

In various embodiments, the additive is a mixture of more than one chemical compound.

The ninth aspect of the invention differs from the eighth aspect in that the additive is not mixed with the biomeal oil before the additive and biomeal oil are fed into the distillation reactor, and in that the inlet for the additive may be further downstream of the inlet for biomeal oil, or vice versa.

The description relating to the seventh aspect and the related embodiments relating to the seventh aspect are also applicable to the eighth and ninth aspects of the present invention.

In an embodiment of any of the seventh to ninth aspects of the invention, the system further comprises a reactor in which one or more heavier fractions are fed for thermal treatment to produce additional lighter products.

According to a tenth aspect of the present invention there is provided a system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to a hydrotreating reactor containing a hydrotreating catalyst for hydrotreating therein to form a hydrotreated product, and

the hydrotreating reactor has means for receiving at least one hydrotreating agent and at least one outlet for discharging hydrotreated product and unconverted hydrotreating reactant.

According to an eleventh aspect of the present invention there is provided a system for reactive distillation of a biocrude oil, the system comprising:

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to a hydrotreating reactor containing a hydrotreating catalyst for hydrotreating therein to form a hydrotreated product, and

the hydrotreating reactor has means for receiving at least one hydrotreating agent and at least one outlet for discharging hydrotreated product and unconverted hydrotreating reactant.

According to a twelfth aspect of the present invention there is provided a system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

at least one further inlet for feeding an additive into the distillation reactor;

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to a hydrotreating reactor containing a hydrotreating catalyst for hydrotreating therein to form a hydrotreated product, and

the hydrotreating reactor has means for receiving at least one hydrotreating agent and at least one outlet for discharging hydrotreated product and unconverted hydrotreating reactant.

In a preferred embodiment of any of the tenth to twelfth aspects of the invention, the system further comprises at least one means to heat the fraction in the hydrotreating reactor only when the fraction is in contact with a hydrotreating catalyst that has been heated to a hydrotreating reaction temperature at which the catalyst is capable of providing activated hydrogen for the hydrotreating reaction to occur. In a further preferred embodiment, the fraction to be hydrotreated is heated by mixing the fraction with a hot stream of a hydrogenating agent, which may be hydrogen.

In an embodiment of any of the tenth to twelfth aspects of the invention, the means for receiving a hydrogenation reagent into the hydrotreating reactor is the same inlet for the fraction to be hydrotreated, wherein the fraction and hydrogenation reagent are rapidly mixed. In an alternative embodiment, the means for receiving a hydrogenation reagent into the hydrotreating reactor is different from the inlet for the fraction to be hydrotreated.

In embodiments of any of the eleventh and twelfth aspects of the invention, the additive, which may be a single compound or a mixture, performs any or all of the functions of reacting with the biocrude oil, catalyzing/inhibiting the reaction of the biocrude oil, or solubilizing the biocrude oil and/or its reaction products during distillation. In a further embodiment, the additive participates in the hydrotreating reaction during hydrotreating.

In an embodiment of any of the tenth to twelfth aspects of the invention, reducing the partial pressure of the components in the product mixture is achieved with any one or combination of a pressure let down valve and the introduction of a further fluid. Importantly, in a preferred embodiment, the additional fluid is a hydrogenation reagent. The hydrogenation agent may be hydrogen.

In embodiments of any of the tenth to twelfth aspects of the invention, each system may further comprise one or more hydrotreating reactors for hydrotreating of other fractions formed during distillation.

In a further embodiment of any of the tenth to twelfth aspects of the invention, each system may further comprise means for cooling and condensing the volatile phase into more than one fraction and means for moving each fraction into a different hydrotreating reactor in which hydrotreating is to be carried out.

In a still further embodiment of any of the tenth to twelfth aspects of the invention, the hydrogenation reagent comprises one or more H-donating compounds that can provide activated hydrogen in the hydrotreating reactor. In a further particular embodiment, the hydrogenation reagent comprises one or more compounds capable of generating free radicals to stabilize broken bonds in the hydrotreating reactor. In particular embodiments, the hydrogenation reagent comprises a recovered hydrotreated product. In a further particular embodiment, the hydrogenation reagent comprises hydrogen.

In yet a further embodiment of any of the tenth to twelfth aspects of the present invention, the lighter fraction and the heavier fraction are separated in a respective hydrotreating reactor hydrotreating at least one separated fraction, wherein an initial section of the hydrotreating reactor performs the separation function.

In an even further embodiment of any of the tenth to twelfth aspects of the invention, the system further comprises a reactor in which one or more heavier fractions are fed for thermal treatment to produce additional lighter products that are further hydrotreated.

In an embodiment of any of the tenth to twelfth aspects of the invention, the bio-crude oil is a bio-oil from pyrolysis of a carbonaceous feed comprising biomass. In a further particular embodiment, the bio-crude oil is a bio-oil from pyrolysis of biomass. In another embodiment, the biological crude oil is a product from hydrothermal liquefaction of a carbonaceous feed comprising biomass or a product from hydrothermal liquefaction of biomass.

According to a thirteenth aspect of the present invention, there is provided a system for reactive distillation of a biocrude oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to be reformed into a reforming reactor for reforming therein to form a reformed product gas; and

a reforming reactor having at least one inlet for receiving at least one reforming agent and at least one outlet for discharging reformate and unconverted reforming reactant.

According to a fourteenth aspect of the present invention, there is provided a system for reactive distillation of a biocrude oil, the system comprising:

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to be reformed into a reforming reactor for reforming therein to form a reformed product gas; and

a reforming reactor having at least one inlet for receiving at least one reforming agent and at least one outlet for discharging reformate and unconverted reforming reactant.

According to a fifteenth aspect of the present invention, there is provided a system for reactive distillation of a biomeal oil, the system comprising:

at least one inlet for feeding a biomeal crude oil formed by heat treatment of a carbonaceous feed comprising biomass into a distillation reactor that can be pressurized;

at least one further inlet for feeding an additive into the distillation reactor;

a heat source and means for heating the biomeal oil at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for the product mixture to exit the distillation reactor to enter the vaporization vessel;

means for reducing the partial pressure of the components in the product mixture so that the volatile substances in the product mixture evaporate to form different fractions;

means for passing at least one of said fractions to be reformed into a reforming reactor for reforming therein to form a reformed product gas; and

a reforming reactor having at least one inlet for receiving at least one reforming agent and at least one outlet for discharging reformate and unconverted reforming reactant.

In embodiments of any of the fourteenth and fifteenth aspects of the invention, the additive, which may be a single compound or a mixture, performs any or all of the functions of reacting with the biological crude oil, catalyzing/inhibiting the reaction of the biological crude oil, solubilizing the biological crude oil and/or its reaction products during distillation, or participating in the reforming reaction during reforming.

In embodiments of any of the thirteenth to fifteenth aspects of the invention, reducing the partial pressure of the components in the product mixture may be achieved with any one or combination of a pressure let down valve and the introduction of additional fluids. Importantly, in a preferred embodiment, the additional fluid is part of a reforming agent that may include steam.

In an embodiment of any of the thirteenth to fifteenth aspects of the invention, the bio-crude is a bio-oil from pyrolysis of a carbonaceous feed comprising biomass. In a further particular embodiment, the bio-crude oil is a bio-oil from pyrolysis of biomass. In another embodiment, the biological crude oil is a product from hydrothermal liquefaction of a carbonaceous feed comprising biomass or a product from hydrothermal liquefaction of biomass.

In an embodiment of any of the thirteenth to fifteenth aspects of the invention, the reforming agent is H₂O (steam), CO₂Air, oxygen or H₂One or more of (a).

In a further embodiment of any of the thirteenth to fifteenth aspects of the present invention, the system further comprises one or more reforming reactors for reforming other fractions formed during the distillation. This allows different distillation fractions to be reformed under different conditions.

Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a flow diagram of a process and system for reactive distillation of a bio-crude according to an embodiment of the present invention;

FIG. 2 is a flow diagram of a process and system for reactive distillation of a bio-crude according to another embodiment of the present invention;

FIG. 3 is a flow diagram of a process and system for reactive distillation of a bio-crude according to a further embodiment of the present invention; and

fig. 4 is a flow diagram of a process and system for reactive distillation of a bio-crude according to still further embodiments of the present invention.

Detailed Description

Embodiments of the present invention relate to methods and systems for reactive distillation of biological crude oil. It should be emphasized that the present invention can be practiced in either batch or continuous operation. Some exemplary embodiments of the invention will be explained below, with particular attention to continuous operation. However, the present invention is not limited to these embodiments.

Fig. 1 shows a process and system 100 for reactive distillation of a bio-crude oil to produce a lighter fraction and a heavier fraction. Bio-oil from pyrolysis of biomass is used as bio-crude oil to illustrate specific embodiments.

Many pyrolysis technologies can be used to produce bio-oil from the pyrolysis of various biomass resources. In this embodiment, bio-oil is produced from the mill pyrolysis of eucalyptus dwarf biomass according to the technique disclosed in PCT/AU 2011/000741.

The bio-oil 101 to be distilled is stored in a refillable tank 105. High pressure pump 110 is used to feed bio-oil 101 into distillation reactor 125. The distillation reactor 125 can be pressurized. In one embodiment, it is pressurised to 7MPa when in use. The operating pressure can be within a wide range. Therefore, it is preferable to construct distillation reactor 125 using steel. In embodiments, distillation reactor 125 is made of a coil or series of coils. This is a significant advantage because the coiled tube structure provides a large heat transfer surface area while it can maintain high pressures. In an alternative embodiment, a bank of tubes similar to the arrangement in a shell-and-tube exchanger is used.

Distillation reactor 125 is heated by immersion in a bath/bed 130 of fluidized sand. The fluidized sand bath 130 has the excellent ability to provide a relatively uniform temperature distribution inside the bed. As the bio-oil flows through distillation reactor 125, it will be indirectly heated by the sand. In an alternative embodiment, a bank of tubes is used as the distillation reactor and heated using a hot fluid in a similar arrangement to that in a shell and tube heat exchanger.

As will be explained later, a back pressure regulator 198 is used to maintain system pressure. As the bio-oil 101 is heated at elevated pressure in the distillation reactor 125, a reaction associated with the bio-oil will occur to form a product mixture comprising reaction products and unreacted components. The product mixture then exits distillation reactor 125 as stream 126.

In an embodiment, the additional fluid 135 is used to reduce the partial pressure of the components in the product mixture. Fluid 135 is supplied from a high pressure source and then its pressure is regulated to a desired pressure level with pressure regulator 140 before its flow rate is measured with flow metering device 145. The fluid 135 then enters a heater 150, which is a coil or series of coils 150, to be heated. In alternative embodiments, heater 150 may be an array of tubes or any other suitable device. The coil 150 is heated by immersion in a fluidized sand bath (130) that also houses and heats the distillation reactor 125. In an alternative embodiment, a separate tool (e.g., another fluidized sand bed or shell and tube heat exchanger) is used to heat fluid 135. In one embodiment, the fluid is a gas. In a preferred embodiment, the fluid is hydrogen.

The heated fluid 135 exiting the coil 150 mixes with the hot product mixture 126 exiting the distillation reactor 125 to form a new stream 151 that then enters the vaporization vessel 155. Upon mixing, the fluid 135 dilutes the product mixture 126 such that the partial pressures of the components therein are reduced, so that upon mixing some limited degree of evaporation can occur. However, by carefully controlling the conditions (especially for short mixing times), evaporation occurs primarily in the evaporation vessel 155. Evaporation is an endothermic process. In one embodiment, the vaporization vessel is shaped as a coil or series of coils 155 that are heated by immersion in the fluidized sand bath 130. The fluidized sand bath for the vaporization vessel 155, the fluidized sand bath for the distillation reactor 125, and the fluidized sand bath for the heater 150 may be the same or different. The arrangement is effective to provide heat for the evaporation to maintain the evaporation operating temperature. In an alternative embodiment, the evaporation vessel is in the form of a bank of tubes arranged in a similar arrangement to a shell and tube heat exchanger. The vaporization vessel can be any suitable device.

After evaporation in the evaporation vessel 155, the stream 156 exiting the vessel 155 may include multiple phases, which then enter the separator 160. The condensed phase 164 from separator 160 is discharged as stream 166 from valve 165 and the vapor phase exits separator 160 as stream 167. The temperature of the separator 160 needs to be well controlled. In one embodiment, the separator 160 is maintained at the same temperature as the vaporization vessel 155. In a particular embodiment, distillation reactor 125, heater 150, vaporization vessel 155, and separator 160 are all immersed in the same fluidized sand bath 130. In another embodiment, the separator is maintained at a different temperature (e.g., a lower temperature) than the temperature of distillation vessel 155 using another fluidized sand bath or other means.

In one embodiment, stream 167 is condensed together as a distillate (with the exception of some minor amounts of uncondensed gaseous products and uncondensed components in stream 135). In another embodiment, stream 167 can undergo gradual cooling and condensation in separator 170, separator 180, and separator 190 to produce condensed products and discharged as streams 176, 186, and 196, respectively, through valve 175, valve 185, and valve 195. Many cooling means known to those skilled in the art may be used (details not shown in fig. 1). Streams 177 and 187 are intermediate volatile streams. Stream 197 will contain uncondensed gaseous products and uncondensed components from stream 135. After passing through the back pressure regulator 198, the uncondensed material will be discharged from the system 100 as stream 199. There may be any reasonable number of separation stages, suitable separators (e.g., 160, 170, 180, and 190) and interstage cooling (not shown) to produce product fractions (e.g., 166, 167, 176, 177, 186, 187, 196, and 197).

In a further embodiment, the separator and interstage cooling may be replaced by conventional distillation columns known to those skilled in the art. When pressure let-down devices (e.g., valves) are used, the distillation column can be operated at various pressures.

Now back to the distillation reactor 125. The use of a back pressure regulator 198 maintains the distillation reactor at elevated pressure. Evaporation of lighter materials is greatly hindered inside the distillation reactor 125 (after heating in heater 150 before product stream 126 is mixed with fluid 135), allowing the desired reaction to occur between lighter and heavier materials.

In an embodiment, system 100 further comprises one or more reactors (not shown in fig. 1) into which one or more heavier fractions are fed for thermal treatment to produce additional lighter products. Lighter products can be collected separately or combined with any of streams 167, 177, 187 and 197.

In some applications, the heavier fractions (any of streams 166, 176, 186, and 196) may be used as fuel. Additional substances (e.g., methanol or other solvents) may be blended with the heavier fractions to alter fuel properties such as viscosity and ignition characteristics.

The system 100 also includes means for introducing an additive 114. In one embodiment, additive 114 is pumped (120) from its refillable storage tank 115 to mix with bio-oil 101 to form feed mixture 123. The feed mixture 123 then enters the distillation reactor 125.

The additive 114 may perform any or all of the following functions: as a reactant with the bio-oil, as a catalyst/inhibitor to catalyze/inhibit the intrinsic reactions of the bio-oil under elevated temperature and pressure conditions in the distillation reactor, or as a solvent to dissolve heavier materials present in the distillation reactor.

The additive 114 may be a mixture of various materials that perform the above-mentioned functions.

In a further embodiment (not shown in fig. 1), the additive 114 is introduced into the distillation reactor at a point downstream of the inlet of the distillation reactor.

In still further embodiments (not shown in fig. 1), the additive 114 is introduced after the distillation reactor, for example, mixed with the product mixture 126.

In yet a further embodiment (not shown in fig. 1), the additive 114 is introduced in any or all of the ways mentioned above: before distillation reactor 125, at a point downstream of the inlet of distillation reactor 125, and/or after the outlet of distillation reactor 125.

In a particular embodiment, the additive 114 is methanol. In another particular embodiment, the additive 114 is acetone. In a further embodiment, the additive is a mixture of acetone and methanol.

Fig. 2 shows a process and system 200 for reactive distillation of a bio-crude integrated with hydrotreating of a fraction to produce a lighter fraction and a heavier fraction. Bio-oil from pyrolysis of biomass is used as bio-crude oil to illustrate specific embodiments.

Many of the numbers in fig. 2 (method and system 200) are the same as those in fig. 1 (method and system 100) and have the same roles as those in system 100.

Lighter fraction 167 resulting from reactive distillation of bio-oil 101 is fed directly into hydrotreating reactor 210 containing catalyst 230 to produce hydrotreated product stream 215. Catalyst 230 may be a mixture of catalysts. The hydrotreating reactor may contain different catalysts at different locations, for example in different sections of the reactor along the direction of the material flow. In an embodiment, the hydrogenation reagent stream 220 is also fed to the hydrotreating reactor. In a particular embodiment, the hydrogenation reagent is hydrogen. In a further particular embodiment, stream 167 and stream 220 are rapidly mixed at the beginning of the cone forming the inlet section of the hydrotreating reactor 210. Many different hydrotreating techniques may be suitable, but a particularly suitable hydrotreating technique is that disclosed in PCT/AU 2013/000825.

Consistent with the teachings of PCT/AU2013/000825, the lighter fraction 167 should be heated rapidly in the presence of a catalyst 230, which catalyst 230 has been at an elevated temperature and is effective to provide activated hydrogen. The elevated temperature referred to herein may be in the range of the hydrotreating temperature. To achieve rapid heating of stream 167, stream 220 is superheated, i.e., above the hydrotreating temperature, so that its thermal energy can be transferred to the material in stream 167 as they are mixed in the presence of catalyst 230.

In another embodiment, stream 220 may be a mixture including, for example, hydrogen and other components. In a particular embodiment, the stream contains a hydrogen donating agent. In a further embodiment, the hydrogen donating agent is a hydrotreated product. For example, a portion of hydrotreated product stream 215 or a portion of stream 257 or stream 267 can be recovered (not shown in fig. 2) and become a portion of stream 220. For example, a reagent containing hydrogenated aromatic and/or cycloaliphatic hydrogen donor may react with some of the components in stream 167 to supply activated hydrogen for the components in stream 167. For example, when mixed with stream 220, chemical bonds in the components in stream 167 can break as the stream is heated, and/or in hydrotreating reactor 210. The hydrogen donating agent in stream 220 can then supply activated hydrogen to stabilize the bond breaking (which can be part of the hydrotreating reaction), while the hydrogen donating agent is dehydrogenated. The dehydrogenated hydrogen donating agent can then be rehydrogenated on the surface of the catalyst to continue the hydrogen donating process. In this way, the hydrogen donating agent can act as a "hydrogen shuttle" to transfer hydrogen in the hydrogenating agent, via catalyst 230, to the component in stream 167 to be hydrotreated. The hydrogen shuttling process may be particularly useful for heavy molecules in the stream 167 that have difficulty contacting active sites on/in the catalyst due to their size, especially active sites in the micropores of the catalyst. Therefore, the hydrogen shuttling process can greatly help reduce coke formation, particularly in hydrotreating reactor 210, due to heavy components in the bio-oil that have remained in stream 167.

Stream 220 may also contain materials that can react to produce other types of activated species, such as methyl radicals. These free radicals may also stabilize broken bonds in the components of stream 167.

The additive 114 may be selected to be capable of supplying hydrogen or generating other activating species as described above.

The hydrotreating reaction is strongly exothermic, which can lead to "runaway" conditions where the temperature in the hydrotreating reactor becomes very high and dangerous. The heat of reaction must be removed to maintain the reaction temperature within the desired range. In one embodiment, heat exchange means 235 is installed inside the hydrotreating reactor. In a particular embodiment, the heat exchange means is a coil or series of coils 235 in the hydrotreating reactor. Heat exchange medium 240 flows through coil 235, carrying heat away. The heat exchange medium may enter from an upper inlet or a lower inlet. Heat exchange coil 235 also plays an important role in providing heat to the inlet section of the hydrotreating reactor to heat the incoming material in stream 167. In other words, heat exchange coil 235 serves a dual purpose in providing heat in the initial stage of the hydrotreating reactor and removing heat in the later (downstream) stage of the hydrotreating reactor.

The hydrotreating reactor 210 may be positioned vertically upward (fig. 2) or in any other orientation relative to the ground. For example, the hydrotreating reactor 210 may be placed vertically upside down with the inlet in a lower position.

Hydrotreated product stream 215 is subjected to stepwise cooling and condensation (250 and 260) to produce different product fractions 256 and 266 which are discharged through valve 255 and valve 265. Stream 257 is an intermediate between the steps. The cooling and condensation can be performed in any number of steps (two steps are shown in fig. 2 as an example). A back pressure regulator 278 is used to maintain system pressure. While some of stream 267 (in FIG. 2) is vented (stream 279), the remainder can be recovered (not shown in FIG. 2) via stream 220 to the hydrotreating reactor. Recirculation may also operate from any or all of streams 215, 257, or 267.

The heavier fraction 166 from the reactive distillation may also be hydrotreated in another hydrotreating reactor. Similarly, reactive distillation may have multiple steps of cooling and condensing (160, 170, 180, and 190 in fig. 1 as examples) to produce different fractions (166, 176, 186, and 196). All of these different fractions may be hydrotreated together or separately in different hydrotreating reactors. The invention provides means for producing these fractions and means for hydrotreating these fractions in different hydrotreating reactors under conditions suitable for hydrotreating each fraction. In some particular embodiments, any heavier fractions 166, 176, 186, and 196 may be thermally treated at higher temperatures in another reactor or reactors to produce additional lighter products. The light products may then be hydrotreated.

Fig. 3 shows a process and system 201 for reactive distillation of a bio-crude integrated with hydrotreating of a fraction to produce a lighter fraction and a heavier fraction. Similar to system 200, bio-oil from pyrolysis of biomass is used as bio-crude oil to illustrate specific embodiments. The numbers in fig. 3 are the same as those in fig. 2 (method and system 200) and fig. 1 (method and system 100) and have the same uses as those in system 200 and system 100.

The main difference between system 201 and system 200 is that the lower section of the hydrotreating reactor 210 also performs the function of a separator. In other words, the separator 160 in fig. 2 is integrated with the hydrotreating reactor 210 such that the separator 160 in fig. 2 becomes the lower section of the hydrotreating reactor 210 in fig. 3. Stream 220 enters the hydrotreating reactor 210 from the bottom. In fig. 3, the reaction fluid flows upward in hydrotreating reactor 210. The stream 156 exiting the vessel 155 enters the bottom section of the reactor 210. Stream 156 is mixed with stream 220, which may further vaporize or condense some of the material in stream 156. After mixing, stream 164 exiting reactor 210 contains most of the heavier material in stream 156, which is discharged as stream 166 from valve 165, while the lighter material contained in stream 156 flows upward in the hydrotreating reactor for hydrotreating therein. Product stream 215 exits hydrotreating reactor 210 from the top thereof and enters unit 250. The functions of all downstream units (250, 256, 260, 266, and 278) and streams (256, 257, 266, 267, and 279) are the same as those of system 200 in fig. 2.

There may be more than one hydrotreating reactor in series for system 200 and system 201. In one embodiment, each hydrotreating reactor may have a raw bio-oil fraction feed (e.g., stream 167 in fig. 2 or stream 156 in fig. 3) from its own reactive distillation system produced using raw bio-oil (bio-oil 101) that is the same as defined by the numbers of 101 to 167 (fig. 2) or 101 to 156 (fig. 3). For the second hydrotreating reactor or each further downstream hydrotreating reactor, the hydrogenation reagent stream (e.g., 220) may comprise fresh hydrogenation reagent and a product stream (e.g., 215) from a preceding hydrotreating reactor.

Fig. 4 shows a process and system 300 for reactive distillation of a bio-crude to produce a lighter fraction and a heavier fraction, integrated with reforming of the fraction to produce a synthesis gas product. Synthesis gas may also be used to produce hydrogen. Bio-oil from pyrolysis of biomass is used as bio-crude oil to illustrate specific embodiments.

Many of the numbers in fig. 4 (method and system 300) are the same as those in fig. 1 (method and system 100) and have the same uses as those in method and system 100.

The lighter fraction 167 produced by the reactive distillation of bio-oil 101 is passed through a pressure regulating device 310 to change its pressure to a level close to the desired operating pressure for reformer 320 (to become stream 305). In one embodiment, the reformer 320 operates at a pressure near atmospheric (ambient) pressure.

Stream 305 is mixed with a stream 330 containing a reforming agent. In one embodiment, the reforming agent is a mixture of air and steam to achieve autothermal reforming operation. In a further embodiment, oxygen or oxygen-enriched air is substituted for air to produce a synthesis gas that contains little nitrogen. In another embodiment, if a separate heat source is available to supply heat to the reformer 320 (not shown in fig. 4), the reforming agent is steam. In all cases, CO₂And H₂Or may be part of the reforming agent mixture. The mixing of streams 305 and 330 can be done just before they enter the reformer 320, at the inlet of the reformer 320, or inside the reformer 320.

The reforming reaction in the reformer 320 is selected to convert as much of the organic components in streams 305(167) to synthesis gas (primarily CO, H)₂And CO₂). If the synthesis gas is subsequently used to generate electricity, light hydrocarbons such as CH in the synthesis gas are increased₄、C₂H₆And C₃H₈The concentration of (b) will be beneficial.

The reformer 320 may contain various catalysts.

Reformate stream 335 may contain various undesirable components such as tarry material, inorganic vapors (e.g., K volatilized from biomass and present in bio-oil 101 during pyrolysis), and NO_x/SO_xAnd their precursors. An important advantage of the present invention is that inorganic vapors in stream 167 are minimized. It is often necessary or beneficial to remove these organic and inorganic impurities from reformate gas 335. Many different hot gas cleaning techniques can be used for this purpose, but the technique disclosed in PCT/AU2014/001135 is particularly advantageous for this purpose. In one embodiment, the hot gas cleaning is performed in two stages. In the first stage (340), the product gas stream 335 is passed through a bed of coke or a bed of coke-supported catalyst, with the product gas flowing in a direction perpendicular to the flow direction of the coke catalyst (not shown). The key function of the first stage is to reform the tarry material to destroy impuritiesSubstances, e.g. NH₃HCN and H₂S and removes any large particles, if any. Stream 345 exiting the first stage enters a second stage (350) containing a porous medium. The key function of the second stage is to cool the product stream 345 to recover heat energy and condense the remaining organic and inorganic impurities on the porous media. The porous media may comprise coke or an adsorbent comprising coke. In heat exchangers also housing porous media, cooling is performed using heat exchange media (see PCT/AU 2014/001135). Clean product gas is produced as stream 355.

The method and system 300 of the present invention also provides the option of reforming or combusting the heavier fraction 164 from the reactive distillation of the bio-crude. Stream 164 is passed through a pressure regulating device/valve 165 to form stream 166 at a pressure level near the desired operating pressure for reformer 360. Stream 166 is mixed with the mixture of reforming agent 365 before entering reformer 360, at the inlet of reformer 360, or after inside reformer 360. Stream 365 may contain high concentrations of oxygen and other reforming agents, such as steam and CO₂. In particular embodiments, stream 365 is primarily air or oxygen, with heavier fraction 164(166) being combusted therein. The reformate gas 367 exiting the reformer 360 may enter the reformer 320 or enter a hot gas cleaning system (340). The ash 366 is discharged.

An important advantage of reactive distillation is that the raw bio-oil 101 is separated into a lighter fraction 167 and a heavier fraction 164, which have very different reforming activities and can be reformed under very different conditions. In a particular embodiment, the heavier fraction 164 is simply combusted with a high concentration of oxygen in the reformer 360. The thermal energy embedded in the product gas 367 is used to meet the heat requirements of the endothermic reaction in the reformer 320. The lighter and more reactive fraction 167 can thus be reformed with less oxygen at the reformer 320 and thus with greater efficiency. Burning the heavier and intractable fraction (164) represents the fastest and most efficient way to reform the bio-oil 101.

Another important advantage is that the lighter fraction 167, which has a reduced propensity to coking, can be catalytically reformed in a reformer 320 having a longer catalyst life, while the heavier fraction, which has a better propensity to form coke, can be burned or reformed without catalyst.

In an embodiment, one or more reforming reactors operate as a combustion reactor. In a further embodiment, the reformate from any or all of the reforming or combustion reactors is further subjected to cleaning using coke or coke-loaded catalyst, for example using the two-stage hot clean gas cleaning process (340 and 350) mentioned above.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention, as the word "comprises" or variations such as "comprises" or "comprising" is used in an inclusive sense.

It will be understood that, if any prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in australia or in any other country.

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Method and system for reactive distillation of biological crude oil

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