阅读说明：本技术 生物质催化热裂解流出物中有价值成分的有效回收 (Efficient recovery of valuable components from biomass catalytic pyrolysis effluents ) 是由 R·迪尼 C·鲁伊斯马丁尼兹 A·B·帕格特 M·F·P·雅克顿 F·J-M·弗尤格奈特 于 2017-07-27 设计创作，主要内容包括：一种方法,包括从生物质催化热解工艺的流出物中分离出富萘油相、酚类油和含有废气、水和BTX的蒸汽相,由此可将所述蒸汽相冷凝将液体水和液态烃与气相废气和BTX分离。(A method comprising separating a naphthalene rich oil phase, phenolic oils, and a vapor phase containing offgas, water, and BTX from the effluent of a catalytic biomass pyrolysis process whereby the vapor phase can be condensed to separate liquid water and liquid hydrocarbons from the vapor phase offgas and BTX.)

A method for separating components in a biomass catalytic pyrolysis process effluent, comprising the steps of:

a1) optionally cooling the biomass catalytic pyrolysis effluent,

a2) optionally quenching the biomass catalytic pyrolysis effluent or the effluent of step a1), if step a1) is performed,

a3) optionally separating tar from the biomass catalytic pyrolysis effluent or from the effluent of step a1) or from the effluent of step a2), if step a1) and/or step a2) are performed,

a) fractionating the biomass catalytic pyrolysis effluent or the effluent from step a1) or a2) or a3), if step a1) and/or step a2) and/or step a3) to produce a naphthalene oil-rich effluent, a phenolic oil effluent and a gas effluent comprising off-gas, water and gas BTX;

b) separating and partially condensing the gaseous effluent comprising off-gas, water and gaseous BTX from step a) to produce a gaseous effluent comprising off-gas and gaseous BTX, a liquid effluent comprising hydrocarbons including hydrocarbons selected from the group consisting of benzene, toluene, xylene, and combinations thereof, and a liquid effluent comprising water and less than 1000ppmw of phenolic compounds; and is

c) Optionally recovering BTX from the liquid effluent comprising hydrocarbons and/or the gaseous effluent of step b).

2. The process of claim 1 wherein the quenching step a2) comprises contacting with a naphthalene rich oil.

3. The process of claim 1, wherein the cooling in step a1) comprises heat exchange in a heat exchanger at a temperature to avoid condensation, and wherein the quenching step a2) comprises contacting with a naphthalene rich oil.

4. The process of claim 1 wherein the quenching step a2) comprises direct contact with naphthalene-rich oil at least partially from the bottoms stream of the fractionation column of step a).

5. The process according to claim 1, wherein the partial condensation in step b) is carried out by quenching the gaseous effluent from step a) by contact with water.

6. The process according to claim 1, wherein the partial condensation in step b) is carried out by heat exchange in a heat exchanger.

7. The process of claim 1, wherein optional step c) of recovering BTX comprises an absorption step c1) of the gaseous effluent from step b), followed by a distillation or fractionation step c2) of separating a product comprising BTX and lean oil.

8. The process of claim 7 wherein absorption step c1) comprises contacting the gaseous effluent from step b) with a lean oil in an absorption column to produce an oil rich phase and fractionating the feed comprising the oil rich phase of step c1) in step c2) to recover at least BTX and lean oil.

9. The process of claim 8, wherein the feed to fractionation step c2) comprises the oil-rich phase from step c1), a phenolic oil effluent from step a), and/or the hydrocarbon-containing liquid effluent from step b).

10. The process of claim 9, wherein the lean oil used for absorption in step c1) comprises oil produced from biomass Bio-TCat, the oil comprising compounds present in the Bio-TCat reactor effluent.

11. The process of claim 9, wherein the lean oil used for absorption in step c1) comprises oil not produced by biomass Bio-TCat.

12. The process of claim 11 wherein the lean oil used for absorption in step c1) comprises a diesel fraction.

13. The process of claim 11 wherein the lean oil used for absorption in step c1) comprises an external stream of aromatic hydrocarbons.

14. The process of claim 1, wherein the liquid effluent comprising water of step b) comprises less than 500ppmw of phenolic compounds.

15. The process of claim 1, wherein the liquid effluent comprising water of step b) comprises less than 300ppmw of phenolic compounds.

16. The process of claim 1, wherein the liquid effluent comprising water of step b) comprises 50 or less ppmw of phenolic compounds.

17, methods comprising separating a naphthalene rich oil phase, a phenolic oil and a hydrocarbon containing waste gas, H, from the effluent of a biomass catalytic pyrolysis process₂A vapor phase of O and BTX, whereby said vapor phase can be condensed to separate a liquid effluent from the gas phase off-gas and BTX comprising water and less than 1000ppmw of phenolic compounds and liquid hydrocarbons.

18, A method for separating components in a biomass catalytic pyrolysis process effluent, comprising the steps of:

a) fractionating the biomass catalytic pyrolysis process effluent to produce a naphthalene oil-rich effluent, a phenolics oil effluent, and a gas effluent comprising off-gas, water, and gaseous BTX, and

b) separating and partially condensing said gaseous effluent comprising off-gas, water and gaseous BTX from step a) to produce a gaseous effluent comprising off-gas and gaseous BTX, a liquid effluent comprising hydrocarbons selected from the group consisting of benzene, toluene, xylene and combinations thereof, and a liquid effluent comprising water and less than 1,000ppmw of phenolic compounds.

19. The process of claim 18, wherein the liquid effluent comprising water of step b) comprises less than 500ppmw of phenolic compounds.

20. The process of claim 18, wherein the liquid effluent of step b) comprising water comprises less than 300ppmw phenolic compounds.

21. The process of claim 18, wherein the liquid effluent comprising water of step b) comprises 50 or less ppmw of phenolic compounds.

22, A method for separating components in a biomass catalytic pyrolysis process effluent, comprising the steps of:

a1) cooling the biomass catalytic pyrolysis effluent,

a2) quenching the effluent produced in said step a1),

a3) separating tar from the effluent resulting from said step a2),

a) fractionating the effluent resulting from said step a3) to produce a naphthalene oil-rich effluent, a phenolic oil effluent and a gas effluent comprising off-gas, water and gaseous BTX;

b) separating and partially condensing the gaseous effluent comprising off-gas, water and gaseous BTX from step a) to produce a gaseous effluent comprising off-gas and gaseous BTX, a liquid effluent comprising hydrocarbons selected from the group consisting of benzene, toluene, xylene, and combinations thereof, and a liquid effluent comprising water and less than 300ppmw of phenolic compounds; and is

c) Optionally recovering BTX from the liquid hydrocarbon-containing effluent and/or the gaseous effluent of step b).

23. The process of claim 22, wherein the liquid effluent comprising water of step b) comprises 50 or less ppmw of phenolic compounds.

24. The process of claim 22, wherein the liquid effluent comprising water of step b) comprises from 10 to 50ppmw of phenolic compounds.

Technical Field

The present invention provides efficient fractionation methods for the recovery of benzene, toluene, and xylenes (collectively BTX) and by-products (off-gas, water, phenolic oils, and naphthalene-rich oils) present in a Bio-TCat effluent stream.

Background

The Bio-TCat process involves converting biomass in a catalytic fluidized bed reactor to produce a mixture of aromatics, olefins, and a variety of other materials. It is related to catalytic fast pyrolysis ("CFP") technology, but the conversion occurs with a contact time between the catalyst and the biomass that is greater than typical CFP treatment processes. Aromatic hydrocarbons produced by Bio-TCat include benzene, toluene, xylene, and naphthalene, among others. The olefins include ethylene, propylene and lesser amounts of higher molecular weight olefins. Providing high yields of BTX is a general goal of Bio-TCat technology as they are generally the most valuable products.

The raw effluent from the Bio-TCat process is a complex mixture comprising aromatics, olefins, oxygenates, paraffins, H₂、CO、CO₂Water, char, ash, coke, catalyst fines, and many other compounds, but generally little bio-oil. The manufacture, separation and recovery of various components, especially those found to be more valuable, from such complex mixtures is becoming increasingly important.

In us 8,277,643, us 8,864,984; U.S. patent publication 2012/0203042 a 1; U.S. patent publication 2013/0060070 a1, U.S. patent publication 2014/0027265 a 1; and U.S. patent publication 2014/0303414 a1, each of which is incorporated herein by reference in its entirety, describe apparatus and process conditions suitable for catalytic fast pyrolysis.

WO2012/092075a1 describes methods of separating products from a biomass pyrolysis system to produce cellulosic biomass oil, wherein the treated effluent is very different from the Bio-TCat process and therefore presents problems, for example, the Bio-TCat effluent has a low carbon content because it is filtered in the cyclone of the reaction section, while the biomass pyrolysis effluent contains a large amount of carbon and should be treated quickly.

WO2016/004248a2 describes a process for the recovery of aromatic chemicals from the product stream of a catalytic pyrolysis process comprising quenching the product with process stream water, separating the vapor phase of , recovering aromatics from the vapor phase of , and recovering oxygenates from the liquid phase product of by this arrangement water is condensed with heavy hydrocarbons, of which are oxidized, their affinity for water will cause high water pollution.

In accordance with current commercial practices and disclosures in the art, there is a need for simple and economical methods for fractionating and recovering benzene, toluene, and xylenes (BTX) and by-products (off-gas, water, phenolic oils, and naphthalene-rich oils) from a Bio-TCat effluent stream.

Summary of The Invention

The invention provides a method of separating a biomass catalytic pyrolysis process effluent, the method comprising at least the steps of:

a) fractionating the effluent to produce a naphthalene oil-rich effluent, a phenolic oil effluent, and a gas effluent comprising off-gas, water, and gaseous BTX, and

b) separating and partially condensing said gaseous effluent comprising off-gas, water and gaseous BTX of step a) to produce a gaseous effluent comprising off-gas and gaseous BTX, a liquid effluent comprising hydrocarbons selected from the group consisting of benzene, toluene, xylene and combinations thereof (e.g. predominantly BTX), and a liquid effluent comprising water and less than 1,000ppmw, or less than 500ppmw, or less than 300ppmw, such as 50ppmw or less, such as from 10 to 50ppmw, of phenolic compounds.

The method includes an efficient, improved fractionation scheme for separating various products of an effluent from a biomass catalytic pyrolysis reaction system. The process provides a process for efficiently separating and recovering the desired aromatic products (benzene, toluene and xylene) and by-products (off-gas, water, phenolic oils and naphthalene-rich oils). The effluent from the reaction portion of the biomass catalytic pyrolysis process has optionally passed through a cyclone to separate the catalyst, char, and gases. The effluent from the reaction section preferably contains only solid particles smaller than 10 μm.

In embodiments of the invention, the fractionation scheme used to separate the different products of the effluent from the biomass Bio-TCat reaction system includes cooling and heat recovery.

The combination of steps a) and b), aspects of the invention, allows separation of naphthalene-rich oil, phenolic oil, liquid hydrocarbon effluent (mainly BTX) and liquid water from effluent and vapour streams (still containing valuable gaseous BTX), and absorption of BTX in said gaseous effluent from step b) in a lean oil and regeneration of said lean oil used as absorbent liquid.

Further , an embodiment of the present invention includes the steps of:

a1) optionally cooling the biomass catalytic pyrolysis effluent, for example in a heat exchanger at a temperature to avoid condensation,

a2) optionally quenching the biomass catalytic pyrolysis effluent or the effluent of step a1), if step a1) is performed, for example by contacting with a naphthalene-rich oil;

a3) optionally separating tar from the biomass catalytic pyrolysis effluent or the effluent of step a1) or the effluent of step a2), if step a1) and/or step a2) are performed,

a) fractionating the biomass catalytic pyrolysis effluent or the effluent from step a1) and/or step a2), and/or step a3) to produce a naphthalene oil-rich effluent, a phenolics oil effluent, and a gas effluent comprising off-gas, water, and gaseous BTX;

b) separating and partially condensing said gaseous effluent from step a) comprising waste gas, water and gaseous BTX to produce a gaseous effluent comprising waste gas and gaseous BTX, a liquid effluent comprising hydrocarbons selected from the group consisting of benzene, toluene, xylene and combinations thereof, and a liquid effluent comprising water and less than 1,000ppmw, or less than 500ppmw, or less than 300ppmw, such as 50ppmw or less, such as from 10 to 50ppmw, of phenolic compounds; and is

c) Optionally recovering BTX from the liquid and/or gaseous effluent comprising hydrocarbons of step b).

Furthermore, the optional step c) of recovering BTX may comprise an absorption step c1) of the gaseous effluent from step b), followed by a distillation or fractionation step c2) to separate a product comprising BTX and lean oil. The absorption step c1) may comprise contacting the gaseous effluent of step b) with a lean oil in an absorption column to produce an oil rich phase, and the feed comprising the oil rich phase of step c1) may be fractionated in step c2) to recover at least BTX and the lean oil. The feed to the fractionation step c2) may comprise an oil-rich phase from step c1), a phenolic oil effluent from step a) and/or a liquid effluent comprising hydrocarbons from step b).

The present invention can be used to provide three benefits for fractionation of biomass catalytic pyrolysis process effluent, such as biomass Bio-TCat effluent, previously found in the art, namely: (i) since the tar is first condensed and then hydrocarbons boiling above 150 ℃ are condensed before the water, scaling and water emulsification problems are limited; (ii) the content of oxygen-containing compounds, particularly phenolic compounds and cresol compounds in the wastewater is limited, so that the treatability of the wastewater is improved; (iii) a BTX stream low in oxygenates is recovered. In particular with respect to phenolic compounds in wastewater intended for wastewater treatment, it is known that high concentrations (e.g., greater than 1,000ppmw) of phenolic compounds are toxic to wastewater treatment bacteria. Although such bacteria can easily tolerate 50ppmw or less of such compounds in the water to be treated, they can adapt over time to higher levels up to 1,000ppmw, but it is most desirable that the phenolic compound content in the effluent treated as wastewater is as low as possible, e.g. the liquid effluent comprising water of step b) is used as wastewater.

Accordingly, advantages of the present invention include a method of separating a Bio-TCat process effluent, which comprises separating a phenolics oil effluent, in particular phenolics and cresols, from the Bio-TCat effluent. This limits the problems of plugging of the column and formation of the final water/hydrocarbon emulsion and also limits the phenol content in water and the content of hydrocarbons in water with boiling points greater than 150 ℃.

Brief description of the drawings

FIG. 1 is a schematic representation of the separation process of the present invention.

Fig. 2 is a more detailed schematic of a preferred embodiment of the invention, including a downstream portion that improves BTX recovery.

FIG. 3 is a detailed process diagram of a preferred embodiment of the present invention.

Detailed Description

As used herein, the term "aromatic hydrocarbon" or "aromatic compound" refers to hydrocarbon compounds containing or more aromatic groups such as, for example, mono aromatic ring systems (e.g., benzyl, phenyl, etc.) and fused polycyclic aromatic ring systems (e.g., naphthyl, 1,2,3, 4-tetrahydronaphthyl, etc.), examples of aromatic compounds include, but are not limited to, benzene, toluene, indane, indene, 2-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, trimethylbenzene (e.g., 1,3, 5-trimethylbenzene, 1,2, 4-trimethylbenzene, 1,2, 3-trimethylbenzene, etc.), ethylbenzene, styrene, cumene, xylenes (e.g., p-xylene, m-xylene, o-xylene), naphthalene, methylnaphthalene (e.g., 1-methylnaphthalene), anthracene, 9, 10-dimethylanthracene, pyrene, phenanthrene, dimethylnaphthalene (e.g., 1, 5-dimethylnaphthalene, 1, 6-dimethylnaphthalene, 2, 5-dimethylindane, 2, 5-dimethylnaphthalene, etc.), naphthalene (e, methyl naphthalene, e, methyl indane, pyrene, phenanthrene, methyl indane, , and/or substituted polycyclic aromatic hydrocarbons, i.g., monocyclic and monocyclic benzine, i.g., aromatic hydrocarbons, monocyclic indane, and monocyclic aromatic compounds may also include monocyclic aromatic hydrocarbons.

As used herein, the term "biomass" is given its conventional meaning in the art and is used to refer to any organic source of renewable energy or chemicals. The main components of the composition can be: (1) trees (wood) and all other plants; (2) agricultural products and waste (grains, fruits, garbage silage, etc.); (3) algae and other marine plants; (4) metabolic wastes (manure, sewage) and (5) cellulosic municipal wastes. Examples of Biomass materials are described, for example, in Huber, G.W. et al, "Synthesis of transport Fuels from Biomass: Chemistry, catalysis, and engineering", chem.Rev.106, (2006), pages 4044-.

Biomass is generally defined as a living or recently dead biological material that can be converted for use as a fuel or for industrial production, the standard for biomass is that the material should recently participate in the carbon cycle so that the release of carbon during combustion results in on average no net increase over a reasonably short period of time (for this reason fossil fuels such as peat, lignite and coal are not considered biomass as defined by this because they contain carbon that has not participated in the carbon cycle for a long time so that its combustion results in a net increase in atmospheric carbon dioxide.) biomass most commonly refers to plant material grown for use as biofuels, but it also includes plant or animal material used to produce fiber, chemicals or heat.

As used herein, the term "oxygenate" includes any organic compound containing at least oxygen atoms in its structure, such as alcohols (methanol, ethanol, etc.), acids (e.g., acetic acid, propionic acid, etc.), aldehydes (e.g., formaldehyde, acetaldehyde, etc.), esters (e.g., methyl acetate, ethyl acetate, etc.), ethers (e.g., dimethyl ether, diethyl ether, etc.), substituted-group-containing oxygenated aromatic compounds (e.g., phenol, m-cresol, o-cresol, p-cresol, xylenol, naphthol, benzoic acid, etc.), cyclic ethers, acids, aldehydes and esters (e.g., furan, furfural, etc.), etc.

As used herein, the terms "phenolic oil" and "oxygenate oil" include aromatic compounds having oxygen-containing substituents (e.g., phenol, m-cresol, o-cresol, p-cresol, xylenol, etc.) and other compounds from the reactor effluent of Bio-TCat, typically boiling between 80 and 220 ℃ (e.g., benzene, toluene, p-xylene, m-xylene, o-xylene, indane, indene, 2-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, 1,3, 5-trimethylbenzene, 1,2, 4-trimethylbenzene, 1,2, 3-trimethylbenzene, ethylbenzene, styrene, cumene, propylbenzene, naphthalene, etc.). Phenolic oils and oxygenate oils are streams that typically boil in the temperature range of 80 to 220 ℃. The oxygenate oil has a lower xylene content than the phenolic oil.

As used herein, the term "naphthalene-rich oil" includes naphthalene, methylnaphthalenes (e.g., 1-methylnaphthalene, 2-methylnaphthalene, etc.), dimethylnaphthalenes (e.g., 1, 5-dimethylnaphthalene, 1, 6-dimethylnaphthalene, 2, 5-dimethylnaphthalene, etc.), ethylnaphthalenes, other polyaromatic compounds (e.g., anthracene, 9, 10-dimethylanthracene, pyrene, phenanthrene, etc.), and aromatic and polyaromatic compounds containing heteroatoms (e.g., oxygen, sulfur, nitrogen, etc.). Naphthalene-rich oils are streams that typically boil in the temperature range of about 200 to about 575 deg.c.

As used herein, the term "exhaust gas" includes H₂、CO、CO₂、COS、N₂And hydrocarbons containing 1 to 6 carbon atoms (e.g., methane, ethane, ethylene, propane, propylene, n-butane, isobutane, isobutylene, 1-butene, 2-butene, pentane, pentene, hexaneHexene, etc.).

The term "tar" as used herein is a stream that typically boils in the temperature range of about 250 to about 575 ℃, which stream is typically dark brown or black asphaltic and viscous.

As used herein, the term "lean oil" is the oil used to absorb BTX in an absorption column. The term "lean" means that the oil is "lean" in terms of BTX. "lean oil" typically boils at a temperature above 145 ℃. Lean oil is the liquid entering the absorption column.

As used herein, the term "rich oil" is an oil that exits the absorber that is rich in absorbed BTX. Rich oil is the liquid leaving the absorber.

The present invention relates to fractionation of biomass catalytic fast pyrolysis (Bio-TCat) process reactor effluent.

The temperature of the Bio-TCat reactor effluent is typically in the range of from 300 to 620 ℃, such as from 400 to 575 ℃, for example from 500 to 550 ℃, and the pressure is in the range of from 100 to 1500kPa, for example from 200 to 1000kPa, for example from 300 to 700kPa (pressure expressed as absolute pressure).

The Bio-TCat reactor effluent typically comprises aromatics, olefins, oxygenates, paraffins, H₂、CO、CO₂Water, char, ash, coke, catalyst fines, and many other components. On an anhydrous and solids-free basis, the reactor effluent may comprise 20 to 60%, such as 25 to 55%, such as 30 to 50%, CO; 10 to 50%, e.g. 15 to 40%, e.g. 20 to 35% CO₂(ii) a 0.1 to 10%, e.g. 0.2 to 5%, e.g. 0.3 to 1% H₂(ii) a2 to 15%, e.g. 3 to 10%, e.g. 4 to 8% CH₄(ii) a2 to 40%, such as 3 to 35%, for example 4 to 30% BTX; 0.1 to 10%, such as 0.2 to 5%, for example 0.3 to 3% of an oxygenate; and 1 to 15%, such as 2 to 10%, such as 3 to 6% C₂-C₄An olefin.

The reactor effluent may comprise a steam mixture, with CO and CO, on an anhydrous and solids-free basis₂The sum of (a) is from 30 to 90%, for example from 40 to 85%, for example from 50 to 80%.

The present invention provides processes for recovering BTX (benzene, toluene, xylene) and by-products (off-gas, water, phenolic oils, and naphthalene-rich oils) from a reactor effluent.

In embodiments, the Bio-TCat effluent can be rapidly cooled to prevent the polycondensation reaction from producing significant amounts of by-products.accordingly, the biomass effluent is first cooled in a heat exchanger the recovered heat can be used both to generate steam and to heat the internal process stream.

In general, the invention includes the separation of at least the Bio-TCat effluent to produce a naphthalene oil rich effluent, a phenolic oil effluent, a liquid comprising water, a liquid comprising hydrocarbons (primarily BTX), and a gas effluent comprising off-gas and gaseous BTX. The object of the present invention (steps a) and b)) is the separation of naphthalene-rich oil, phenolic oil and water in the Bio-TCat effluent. The separation may be performed in a single separation device or in different separation devices. The basic fractionation scheme of the present invention is shown in FIG. 1.

More particularly with reference to fig. 1, the effluent of a biomass catalytic pyrolysis process is provided to fractionation system "a" via stream 1. Removing the naphthalene-rich oil from system "a" via stream 2; removing the phenolic oil via stream 3; a gas effluent comprising off-gas, BTX and water is removed via stream 4. Passing the gaseous effluent of stream 4 to separation system "b" from which is removed via stream 5a liquid effluent comprising water and limited phenolic compounds, for example less than 1,000ppmw, or less than 500ppmw, or less than 100ppmw, for example 50ppmw or less, for example from 10 to 50ppmw of phenolic compounds; a liquid effluent comprising hydrocarbons, including hydrocarbons selected from the group consisting of benzene, toluene, xylene, and combinations thereof, is removed via stream 6. A gas effluent comprising off-gas and gaseous BTX is removed via stream 7. The fraction of stream 6 is sent as reflux to system "a" via stream 8 and the remainder of stream 6 is withdrawn via stream 9.

More specifically, the present invention provides a method of separating a biomass catalytic pyrolysis process effluent, the method comprising at least the steps of:

a) fractionating the catalytic pyrolysis process effluent to produce a naphthalene oil-rich effluent, a phenolic oil effluent, and a gas effluent comprising off-gas, water, and gaseous BTX, and

b) separating and partially condensing the gaseous effluent comprising waste gas, water and gaseous BTX of step a) to produce a gaseous effluent comprising waste gas and gaseous BTX, a liquid effluent comprising hydrocarbons (predominantly BTX), and a liquid effluent comprising water and less than 1,000ppmw, or less than 500ppmw, or less than 300ppmw, such as 50ppmw or less, for example from 10 to 50ppmw, of phenolic compounds.

Step a) may be carried out in a fractionation column.

In the preferred embodiments of the invention shown in FIG. 2, step a) and step b) may comprise the sequence cooling the Bio-TCat effluent, quenching the Bio-TCat effluent with the naphthalene-rich oil from step a), removing tars in a knock-out drum, separating the naphthalene-rich oil and the phenolic oil in a fractionation column, and condensing water and hydrocarbons the optional cooling in step a1) may be performed by heat exchange in a heat exchanger at a temperature that avoids condensation, followed by optional quenching by contact with the naphthalene-rich oil in step a 2).

Referring more specifically to fig. 2, the effluent of a catalytic pyrolysis process of biomass is provided via stream 1 to an optional cooling system "a 1", e.g., a heat exchanger, then the cooled pyrolysis process effluent enters an optional quench system "a 2" via stream 10. then the gaseous effluent from the quench system passes via stream 11 and the liquid effluent from the quench system passes via stream 12 into a separation system "a 3". Tar is removed from the separation system via stream 13 and the cooled process effluent passes from the separation drum via stream 14 after Tar removal, then stream 14 is fed to a fractionation system "a". naphthalene-rich oil is removed from system "a" via stream 15, phenolic oil is removed via stream 3, the gaseous effluent comprising offgas, BTX and water is removed via stream 4. naphthalene-rich oil fraction is removed from stream 15 via stream 16 and recycled to quench system "a 2". naphthalene-rich oil 15 remaining in stream 15 is removed via stream 2. stream 4 is fed to separation system "b", wherein the separated effluent comprising stream 5 is passed via a liquid hydrocarbon-containing effluent, and optionally a hydrocarbon-containing hydrocarbon compounds is recovered from the liquid effluent comprising stream 7, and optional hydrocarbon-containing effluent by a xylene recovery system "5396" and optional hydrocarbon-containing effluent, and a hydrocarbon-containing effluent, and a hydrocarbon-containing effluent, a hydrocarbon-containing effluent, which is returned to a hydrocarbon-containing stream 6, and a hydrocarbon-containing effluent, and a hydrocarbon-containing effluent, and a hydrocarbon-containing effluent.

In embodiments, the Bio-TCat effluent stream may be quenched in step a2) by direct contact with naphthalene-rich oil from the fractionation column bottoms stream of step a) which consists essentially of Hydrocarbons (HC) the direct contact with HC fluid is chosen because it allows the HC to condense without the need for water the stability of the naphthalene-rich oil may be problems the temperature of the quench is preferably between 150 and 250℃, typically between 180 and 220℃, to avoid degradation of the naphthalene-rich oil and to prevent deposition and condensation of tars, the pressure of the quench is 100 to 1500kPa, such as 200 to 1000kPa, such as 300 to 700kPa (pressure expressed as absolute pressure).

The separation and removal of tar (the heaviest component of the Bio-TCat effluent) may be carried out in step a3) by means of a knock-out drum, preferably placed before the fractionation column and preferably after the Bio-TCat effluent quench.

After optional cooling, quenching and tar removal, the Bio-TCat effluent is sent to step a) and is carried out on boiling point basis in a fractionation column. The column separates the naphthalene-rich oil and the phenolic oil and includes a reflux stream, a bottoms stream, a sidedraw, and an overhead stream.

An external reflux system can be used to control the function of the column and increase the hydrocarbon partial pressure to prevent water condensation. The reflux stream is composed of a liquid comprising hydrocarbons (mainly BTX) obtained by condensing the vapor flowing overhead.

The bottoms stream consists of at least portions of naphthalene-rich oil that can be used to optionally quench the Bio-TCat effluent.

The purpose of the side cut is to avoid condensation of oxygenates, particularly phenol and water . it is well known that the presence of phenol in waste water streams can negatively impact its treatment, particularly if sent directly to biological waste water treatment.

The vapor phase overhead stream, which is free of components boiling above 200 ℃, is a vapor comprising off-gas, water, and vapor phase BTX. The oxygenate fractions are controlled so that they leave the column as a side draw. Thus, the gas phase stream consists of aromatic compounds (BTX), water and off-gases.

The column was operated to control reflux and pumping (temperature and rate) with the goal of:

the effluent washing (removal of all small solid particles) is carried out at the bottom of the column.

Condensation and separation of the two fractions:

omicron phenolic oil fractions with controlled naphthalene content.

O naphthalene-rich oils with limited valuable product losses.

No water condensation in the column (controlled by partial pressure and temperature at the top of the column).

The pressure of the fractionation column is between 100 and 1500kPa, such as 200 to 1000kPa, for example 300 to 700kPa (pressure expressed as absolute pressure). The temperature of the fractionation column is from 70 to 250 deg.c, for example from 100 to 220 deg.c.

The invention then further step comprises a step b) of at least separating and partially condensing the gaseous effluent from step a) to produce a gaseous effluent comprising waste gas and gaseous BTX, a liquid comprising hydrocarbons (predominantly BTX) and a liquid effluent comprising water, the gaseous effluent from step a) comprising waste gas, water and gaseous BTX.

The gaseous effluent from the top of the fractionation column of step a) is cooled to partially condense water and a BTX-rich HC liquid stream (partially used as reflux for the fractionation column), the two liquid products and the gaseous stream are separated, this step comprises an exchanger or water wash column or similar cooling system and a phase separator device (e.g. a knock-out drum), part of the hydrocarbon (BTX) -containing liquid is returned to the fractionation column of step a) as reflux.

The pressure of the water condensation section is typically in the range 100 to 1500kPa, such as 200 to 1000kPa, for example 300 to 700kPa (pressure expressed as absolute pressure). The temperature of the water condensation section is typically between 5 and 100 c, for example 20 to 50 c.

The gas stream comprising offgas and gaseous BTX exiting step b) may therefore comprise significant amounts of aromatic compounds, in particular benzene, and embodiments may be lean oil absorption the top of the absorber column is fed with a selected lean oil to absorb aromatic compounds (BTX) in the gas stream comprising the upflowing offgas from step b) and gaseous BTX, the gas stream comprising offgas and gaseous BTX from the part of step b) may be compressed prior to entering the absorber column to increase the absorption pressure and increase the absorption efficiency, the pressure of the absorber column is between 100 and 2000kPa, such as between 200 and 1500kPa, such as between 300 and 1000kPa (pressure expressed as absolute pressure), the temperature of the absorber column is between 0 and 100 ℃, such as between 20 and 80 ℃, such as between 30 and 70 ℃.

The rich oil stream comprising the lean oil and absorbed BTX and exiting the bottom of the absorption column may then be sent to a distillation section to separate the products and regenerate the lean oil, which is then recycled to the absorption column. The distillation section may comprise a single or multiple distillation columns depending on the lean oil boiling temperature. The feed to the distillation section comprises rich oil, but may also comprise liquid containing hydrocarbon (BTX) and phenolic oils from the purification section (streams from the fractionation column and water condensation). The pressure in the distillation section is typically between 100 and 1000kPa, such as 100 to 700kPa, for example 100 to 500kPa (pressure is expressed as absolute pressure). The temperature of the distillation section is from 20 to 300 deg.C, for example from 20 to 250 deg.C.

The lean oil may be internal, i.e. composed of compounds produced by the organism Bio-TCat and present in the Bio-TCat reactor effluent, or external, i.e. input from an external source (meaning inventory and make-up for losses). The boiling temperature of the lean oil (internal or external) should be higher than the boiling temperature of the hydrocarbons intended to be absorbed in the absorber. Because of the intended absorption of BTX, the boiling temperature of the lean oil must be above 145 ℃.

When considered for use as an external fluid for lean oil, replenishment may be required because part of the lean oil will enter the exhaust and cannot be recycled to the absorber column, and therefore a lean oil inventory must be maintained.

Examples of internal lean oils may be fractions boiling in the range of 145 to 220 c, including phenol, cresols, hydrocarbons having 8 to 10 carbon atoms (e.g., indane, indene, trimethylbenzene, ethyltoluene, naphthalene, etc.). when the internal stream is selected as the absorptive lean oil, the lean oil composition should be controlled to limit the content of species (naphthalene, cresols, etc.) having freezing points near or above the absorber temperature.

Specifically, a preferred embodiment comprises:

A method for separating the components of a biomass catalytic pyrolysis process effluent, comprising the steps of:

a1) optionally cooling the biomass catalytic pyrolysis effluent,

a2) optionally quenching the biomass catalytic pyrolysis effluent or the effluent of step a1), if step a1) is performed,

a3) optionally separating tar from the biomass catalytic pyrolysis effluent or the effluent from step a1) or the effluent from step a2), if step a1) and/or step a2) are performed,

a) fractionating the biomass catalytic pyrolysis effluent or the effluent from step a1) or a2) or a3), if step a1) and/or step a2) and/or step a3) to produce a naphthalene oil-rich effluent, a phenolic oil effluent and a gas comprising off-gas, water and BTX, i.e. a vapor phase effluent;

b) separating and partially condensing the gaseous effluent comprising off-gas, water and gaseous BTX from step a) to produce a gaseous effluent comprising off-gas and gaseous BTX, a liquid effluent comprising hydrocarbons selected from the group consisting of benzene, toluene, xylene and combinations thereof, and a liquid effluent comprising water and 50ppmw or less, for example, from 10 to 50ppmw, of phenolic compounds; and is

c) Optionally recovering BTX from the liquid and/or gaseous effluent comprising hydrocarbons of step b).

Fractionating step a) may comprise separating the respective streams of naphthalene-rich oil, phenolic oil and vapor phase comprising off-gas, water and BTX. The optional step c) for recovering BTX may comprise an absorption step c1) of the gas stream from step b), followed by a distillation or fractionation step c2) to separate the product and the lean oil.

More specifically, the optional step c) of recovering BTX may comprise a step c1) of absorbing the gas stream from step b) to recover aromatic compounds. The absorption step c1) may comprise contacting the gas stream from step b) with a lean oil in an absorption column and, after absorption, fractionating the obtained oil-rich phase in step c2) to recover at least BTX and the lean oil may be recycled to the absorption step c 1).

The fractionation step c2) may comprise or several distillation columns.

The feed to the fractionation step c2) comprises the oil-rich phase from step c1) and may also comprise the phenolic oil from step a) and/or the hydrocarbon (BTX) -containing liquid phase from step b).

The lean oil used in absorption step c1) may be an oil produced from biomass Bio-TCat comprising the compounds present in the Bio-TCat reactor effluent. The lean oil used in absorption step c1) may be an oil not produced by the biomass Bio-TCat, such as a diesel fraction and/or an external stream of aromatics.

The optional cooling in step a1) may be performed by heat exchange in a heat exchanger at a temperature avoiding condensation and then optionally quenched in step a2) by contact with a naphthalene rich oil. The naphthalene-rich oil may be recycled from the fractionation of step a).

The partial condensation in step b) may be carried out by quenching the gaseous effluent in step a) by contacting it with water. Furthermore, the partial condensation in step b) can be carried out by heat exchange in a heat exchanger.

Thus, the present invention may also be directed to an separation method comprising separating a naphthalene rich oil phase, phenolic oils, and a gas stream containing waste gas, water, and gaseous BTX from the effluent of a biomass catalytic pyrolysis process, optionally tar removed, wherein the gas stream may be partially condensed to separate liquid water and liquid hydrocarbons from gaseous waste gas and BTX.

Further, embodiments of the invention may be directed to a method for separating components in a biomass catalytic pyrolysis process effluent, the method comprising the steps of:

a3) separating tar from the biomass catalytic pyrolysis effluent,

a) fractionating the effluent from step a3) to produce a naphthalene oil-rich effluent, a phenolic oil effluent and a gas effluent stream comprising offgas, water and BTX, and

b) separating and partially condensing the gaseous effluent stream from step a) to separate liquid water and liquid hydrocarbons from the gaseous off-gas and BTX.

It is not necessary to to describe further, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent.

In the examples of embodiments of the present invention provided above and below, all temperatures are corrected in degrees celsius and all parts and percentages are by weight unless otherwise indicated.

Example (see FIG. 3)

1)Bio-Tcat effluent composition

Table 1 shows the composition of the Bio-TCat effluent considered in this example. Table 2 shows the detailed composition of the Bio-TCat effluent considered in this example. In the table, the stream concentrations are in weight percent and the flow rates are in kg/hour. The logistics labels are shown in figure 3.

TABLE 1

Water H₂O.

Uncondensed product H₂、CO、CO₂COS, methane, ethane, ethylene, propane, propylene, n-butane, isobutane, 1-butene, cis-2-butene, trans-2-butene.

BTX is benzene, toluene, o-xylene, m-xylene and p-xylene.

Other monoaromatic hydrocarbons include ethylbenzene, styrene, 3-ethyltoluene, 4-ethyltoluene, n-propylbenzene, isopropylbenzene, 1,2, 3-trimethylbenzene, indane and indene.

The diarylhydrocarbon is naphthalene, 2-methylnaphthalene, 2-ethylnaphthalene, 2, 7-dimethylnaphthalene.

The oxygen-containing compounds comprise 2-propanol, acetone, methyl vinyl ketone, phenol, m-cresol and o-cresol.

Other compounds acetonitrile, dimethyl sulfide, dimethyl disulfide, thiophene, 2-methylthiophene, 3-methylthiophene, n-pentane, isopentane, 1-pentene, n-hexane, 1-hexene, n-heptane, 1-heptene, n-octane, 1-octene, n-nonane, 1-nonene.

TABLE 2

2)Fractionation system (referring more specifically to fig. 3, similar stream and system designations as defined above in fig. 1 and 2 Ji)

Cooling and Heat recovery (step a1)

The Bio-TCat effluent was passed through heat exchanger 101 of step a1) at 568 ℃ (stream 1 of FIG. 3) to recover part of the heat by generating steam, the exit temperature was 400 ℃.

Quenching (step a2)

In step a2), the stream is further quenched to a temperature of 202 ℃, and after cooling the effluent from the bottom of the fractionation column 104 of step a) in heat exchanger 105, the effluent stream is contacted with a cold naphthalene-rich oil quench fluid of 200 ℃ obtained via line 16 in a device similar to annular ring 102.

Tar separation drum (step a3)

After quenching to 202 ℃, the effluent enters the knock-out drum 103 of step a3) to remove the heaviest hydrocarbon molecules (tars) that have condensed. The purpose of the tar knock-out drum is to prevent upstream fouling during fractionation. It also avoids problems caused by the presence of small amounts of hydrocarbon molecules in the water. The velocity and temperature of the quench oil is controlled to regulate tar condensation. Tar is removed via line 13.

Fractionating tower (step a)

The vapor from the tar knock-out drum is passed via line 14 to the fractionation column 104 of step a), which operates at 4.2 bar at the top. The temperature is maintained above the temperature at which most of the water condenses. In this example, the top temperature was 120 ℃ and the separation was carried out using 20 theoretical plates.

The tower serves several purposes:

the main reason for condensing oxygenates, especially phenol, in this column is to avoid their condensation with water in the system at step the advantage is that process water with a phenol content of less than 50ppm is obtained so that it can be subjected to conventional biological waste water treatment.

Condensation of naphthalene-rich oil, which was used in part for direct quenching of the Bio-TCat system. The stream 15 is also used to scrub the vapor and pass through the bottom of the surrounding pump cooling tower via line 20. The stream fraction not used for quenching, consisting of slurry with catalyst fines and char, is purged via line 2.

Continue quenching/separating the Bio-TCat effluent. The vapor stream at the top of the column reached a temperature of 120 ℃. The dew point of water is bounded by about 20 c depending on the partial pressure of water.

Water condensation-water quench tower

once the naphthalene-rich and phenolic oils have been removed from the system, water condenses, hi this example, the water quench tower 106 of step b) serves to limit fouling problems, the water quench tower uses 7 theoretical stages and operates at a pressure of 4bar, the vapor stream is recovered at the top of the water quench tower, and the bottoms stream passes through line 24 to a knock-out drum 107, where liquid water and liquid HC are separated parts of the water are cooled to 33 ℃ in heat exchanger 108 and passed through line 21 to the top of the water quench tower 106 to control the temperature of the vapor product (in this example 3 ℃ thermal process is used), the BTX-rich part of the HC in line 8 is used as reflux for the fractionation tower 104, cooled at 40 ℃ in heat exchanger 109, which reflux serves to control the overhead temperature and water partial pressure to avoid water condensation, in the case shown reflux rate is 170 t/h.

Absorption tower (step c1)

The vapor stream contained 84% of the total BTX. The absorption column 110 of step c1) is used for recovering these valuable products. The absorption column uses the lean oil obtained as bottom product 22 of distillation column 111 of step c2) and consists mainly of cresols and indanes. The absorption column had 8 theoretical plates and a working pressure of 3.7 bar. 98% by weight of the BTX entering the absorber is recovered as lean oil, from which a rich stream 23 enters distillation column 111 to separate the products and regenerate the lean oil.

Distillation column (step c2)

The distillation column 111 processes the phenolic oil fraction, the liquid hydrocarbon (BTX) fraction obtained in the water quench column 106 and a BTX-containing rich oil as absorption liquid. It contains 35 theoretical plates. Four fractions were taken from the column: a BTX fraction passing through line 18 via line 25 at reflux drum 112; water, through line 26 at the reflux drum; lean oil, via line 22 to the absorber; and an oxygenate oil stream, at the bottom of column 111 via line 19.

An important advantage of the present invention over the prior art is that the phenol content in the resulting water is 15ppm, whereas in a different but known version of the prior art (see WO2016/004248a2, table 1) the phenol content is 300ppm wt, well above the biological treatment limit of the wastewater (e.g., less than 300ppmw, preferably 50ppmw or less).

The foregoing examples may be repeated with similar success by substituting of the present invention with the reactants and/or operating conditions as used in the foregoing examples.

From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.