阅读说明：本技术 一种利用生物质制备c6~c18动力燃料的方法 (Preparation of C from biomass6~C18Method for powering fuel ) 是由 邵珊珊 项贤亮 刘成跃 李小华 于 2020-04-20 设计创作，主要内容包括：本发明涉及一种利用生物质制备C<Sub>6</Sub>～C<Sub>18</Sub>动力燃料的方法,主要包括以下步骤：1)在两段式热解反应器中,生物质在金属氧化物催化剂作用下催化热解制备含氧小分子化合物；2)在固定床连续式反应器中,含氧小分子化合物实现一步C-C偶联加氢,形成C<Sub>6</Sub>-C<Sub>18</Sub>范围内的烷烃和芳香烃；3)在回流冷凝器中,C<Sub>6</Sub>-C<Sub>18</Sub>范围内的烷烃和芳香烃按照汽油、煤油、柴油的碳数分布,分级冷凝。该方法各步骤间连续进行,无需催化剂的分离和产物的精馏,极大节约了成本并有效降低了反应时间。且以可再生的生物质为原料,同时制得汽油、煤油、柴油等动力燃料并实现分离,可部分替代传统石油来源的炼制技术。(The invention relates to a method for preparing C by using biomass 6 ～C 18 The fuel power method mainly comprises the following steps: 1) in a two-section pyrolysis reactor, biomass is subjected to catalytic pyrolysis under the action of a metal oxide catalyst to prepare an oxygen-containing small molecular compound; 2) in a fixed bed continuous reactor, the oxygen-containing small molecular compound realizes one-step C-C coupling hydrogenation to form C 6 ‑C 18 Alkanes and aromatics within the range; 3) in a reflux condenser, C 6 ‑C 18 The alkane and the aromatic hydrocarbon in the range are condensed in stages according to the carbon number distribution of gasoline, kerosene and diesel oil. The method has the advantages that the steps are continuously carried out, the separation of the catalyst and the rectification of the product are not needed, the cost is greatly saved, and the reaction time is effectively reduced. Renewable biomass is used as a raw material, and power fuels such as gasoline, kerosene, diesel oil and the like are simultaneously prepared and separated, so that the renewable biomass can partially replace the traditional petroleum sourceThe refining technology of (1).)

1. Preparation of C from biomass₆～C₁₈A method of powering a fuel, comprising the steps of:

(1) the biomass is catalytically pyrolyzed into oxygen-containing small molecular compounds in a two-section pyrolysis reactor, wherein the pyrolysis temperature is 300-460 ℃, the catalysis temperature is 300-460 ℃, and the catalyst is a metal oxide catalyst;

(2) carrying out C-C coupling hydrogenation reaction on the oxygen-containing micromolecule compound in a fixed bed continuous reactor to obtain C₆～C₁₈The power fuel of (1), wherein the pressure in the reactor is 5-7 MPa, the temperature is 300-375 ℃, the catalyst is a supported metal dual-function A/X type catalyst, the hydrogen flow rate is 100-300 mL/min, and the reaction time is 20-60 min;

(3)C₆～C₁₈the power fuel is subjected to fractional condensation in a reflux condenser.

2. The method of claim 1, wherein the metal oxide catalyst in step (1) is one or more of ceria, manganese dioxide, zirconia or titania.

3. The method as claimed in claim 1, wherein the supported metal bifunctional A/X catalyst in step (2) is prepared by using activated carbon, silicon oxide and silicon-aluminum composite carrier SiO as carrier X₂-Al₂O₃Or any of red mud; the active component A is one or more of copper, nickel, platinum, cobalt or iron, and the mass fraction of the active component A is 5-50%.

4. The method according to any one of claims 1 to 3, wherein the pyrolysis temperature in the step (1) is 380 ℃ and the catalytic temperature is 420 ℃.

5. The method according to any one of claims 1 to 3, wherein the pressure in the reactor in the step (2) is 6.2MPa, the temperature is 350 ℃, the flow rate of hydrogen is 200mL/min, and the reaction time is 30 min.

6. The method as set forth in any one of claims 1 to 3, wherein the temperatures of said reflux condenser in said step (3) are set to 10 to 20 ℃, to 10 to 0 ℃ and to-30 to-10 ℃, respectively.

7. The method according to claim 3, wherein the supported metal bifunctional A/X type catalyst is a copper-supported red mud catalyst, a copper-supported activated carbon catalyst, a copper-supported silicon oxide catalyst, a copper-supported silicon-aluminum composite carrier SiO₂-Al₂O₃Any one of a catalyst, a nickel-supported red mud catalyst, an iron-supported red mud catalyst, or a cobalt-supported red mud catalyst.

8. The method of claim 3 or 7, wherein the SiO is supported on a silicon-aluminum composite carrier₂-Al₂O₃The silicon-aluminum ratio is 40-60: 1.

9. the method according to claim 8, wherein the mass fraction of the active component A is 20%.

Technical Field

The invention belongs to the field of preparing liquid fuel and chemical products by catalytic conversion of biomass, and particularly relates to a method for preparing C from biomass₆～C₁₈A method of powering a fuel.

Background

In the world, people are urgently required to find a sustainable alternative energy source against various problems of fossil fuel depletion and environmental protection. The currently used fuel sources are mainly coal, petroleum and natural gas, but the sources are all non-renewable resources, and the power fuel prepared by using fossil fuel can discharge a large amount of carbon dioxide to the atmosphere in the use process, thereby causing greenhouse effect and being extremely not beneficial to environmental protection. Biomass resources, as an inexhaustible energy source, gradually enter the human vision, can be converted into various forms of energy sources and high-value chemicals, and have renewability and low emission. Therefore, the rapid development of biomass energy sources has very important significance for the progress of the human society and the maintenance of civilized forms.

At present, the utilization of biomass in the prior art at home and abroad comprises the preparation of bio-oil by catalytic pyrolysis of the biomass, but the quality problem of the bio-oil is still not ideal. The organic matter components in the bio-oil prepared by direct pyrolysis are very complex, and more than 300 substances can be detected at present. In addition, the biological oil has the problems of high oxygen content, high moisture content, high solid content, high acidity, low heat value, poor thermal stability and the like. In order to realize the effective utilization of the bio-oil, the bio-oil must be further upgraded by hydrofining, catalytic cracking, catalytic reforming, esterification, emulsification and the like.

In recent years, researchers have conducted experimental studies on various production methods in the field of producing power fuels from biomass. The method comprises a grease hydrogenation-deoxidation technology, a Fischer-Tropsch synthesis-hydrogenation quality improvement technology, a biomass hydrolysis-water phase catalytic hydrogenation synthesis technology, an olefin oligomerization technology, a biological pyrolysis oil catalytic quality improvement technology and the like.

For example, in patent CN 107304367 a, a method for preparing branched alkane with carbon number in the range of gasoline, aviation fuel, kerosene and diesel oil by using acetone in biomass pyrolysis product as raw material is proposed. However, the yield of acetone in the biomass pyrolysis product is very low, and even if ketones are prepared by catalytic pyrolysis of biomass, the yield is also low, and the high-efficiency utilization of biomass energy is not met, so that the utilization rate of the biomass pyrolysis product needs to be improved, namely, the full-component utilization of biomass pyrolysis gas is realized.

In patent CN109054875A, a method for converting biomass into liquid fuel with high efficiency is proposed, even if heat is provided by coke generated in the process of catalytic cracking of petroleum, so as to realize conversion of biomass into liquid fuel. However, the liquid fuel directly prepared from biomass has poor quality, the carbon number of the product is difficult to control even if a catalyst is used, and the oil product is acidic and difficult to directly utilize.

From the above, the biomass catalytic pyrolysis is mainly a one-step method for directly preparing the bio-oil at present, and the component analysis of the prepared bio-oil can find that the yield of alkane and aromatic hydrocarbon is below 45%, and the bio-oil contains a large amount of acetic acid, macromolecular compounds and the like, even if the optimized products are extracted by a plurality of subsequent methods, the whole process from the raw material to the target product is independent and separate, discontinuous, low in yield, high in requirement on the raw material, high in cost and difficult to industrially produce.

Disclosure of Invention

In order to solve the above problems, the present invention provides a method for selectively obtaining alkanes and aromatics in the range of gasoline, kerosene and diesel oil, and oxygen-containing small molecular compounds, alkanes and aromatics with high carbon yield by directly using biomass as a raw material, and provides a green route for preparing an excellent liquid energy substitute by using biomass as a raw material. To achieve the above object, the present invention first performs catalytic pyrolysis of biomass by controlling the matching of pyrolysis temperature and catalytic temperatureThe relationship and the reasonable selection of the catalyst are that the carbon number of the catalyst is C as much as possible₈The oxygen-containing small molecular compounds are converted, and then alkane and aromatic hydrocarbon with carbon number in the range of gasoline, kerosene and diesel oil can be directly generated through one-step C-C coupling hydrodeoxygenation reaction. The specific scheme is as follows:

preparation of C from biomass₆～C₁₈A method of powering a fuel, the method comprising the steps of:

(1) performing catalytic pyrolysis in a two-section pyrolysis reactor, wherein biomass is pyrolyzed at the temperature of 300-460 ℃ in a first-section reactor, pyrolysis gas enters a second-section reactor, and an oxygen-containing micromolecule compound is generated at the temperature of 300-460 ℃ through catalysis of a metal oxide catalyst;

(2) carrying out one-step C-C coupling hydrogenation reaction on the oxygen-containing micromolecule compound in a fixed bed continuous reactor to obtain C₆～C₁₈The power fuel of (1), wherein the pressure in the reactor is 5-7 MPa, the temperature is 300-375 ℃, the catalyst is a supported metal dual-function A/X type catalyst, the hydrogen flow rate is 100-300 mL/min, and the reaction time is 20-60 min;

(3)C₆～C₁₈the power fuel is subjected to fractional condensation in a reflux condenser to realize product separation.

The metal oxide catalyst in the step (1) is one or more of cerium dioxide, manganese dioxide, zirconium dioxide or titanium dioxide.

The bifunctional catalyst in the step (2) is a supported metal bifunctional A/X type catalyst, and the carrier X is an active carbon, silicon oxide and silicon-aluminum composite carrier SiO₂-Al₂Any one of O3 or red mud; the active component A is one or more of copper, nickel, platinum, cobalt or iron, and the mass fraction of the active component A is 5-50%.

Preferably, the biomass in the step (1) is pyrolyzed at 380 ℃, the pyrolysis gas enters a second-stage reactor, and the oxygen-containing small molecular compounds are generated at 420 ℃ through catalysis of a metal oxide catalyst.

Preferably, the pressure in the reactor in the step (2) is 6.2MPa, the temperature is 350 ℃, the catalyst is a bifunctional catalyst, the hydrogen flow rate is 200mL/min, and the reaction time is 30 min.

The temperature of the reflux condenser in the step (3) is respectively 10-20 ℃, 10-0 ℃ and-30 to-10 ℃.

The supported metal bifunctional A/X catalyst is a copper-supported red mud catalyst, a copper-supported activated carbon catalyst, a copper-supported silicon oxide catalyst, a copper-supported silicon-aluminum composite carrier SiO₂-Al₂O₃Any one of a catalyst, a nickel-supported red mud catalyst, an iron-supported red mud catalyst, or a cobalt-supported red mud catalyst.

Preferably, the silicon-aluminum composite carrier SiO₂-Al₂O₃The silicon-aluminum ratio is 40-60: 1.

preferably, the mass fraction of the active component A is 20%.

The supported metal bifunctional catalyst is prepared by adopting an isometric impregnation method or a coprecipitation method.

The oxygen-containing small molecule compound comprises acetone, butanone, pentanone, hexanone, heptanone, 2-cyclopentanone, acetaldehyde, butyraldehyde, octanal, furfural, phenol and the like, and the carbon number is kept below C8.

The power fuel of C6-C18 passes through a reflux condenser and is subjected to fractional condensation to obtain alkane and aromatic hydrocarbon in the range of C6-C18 such as gasoline, kerosene and diesel oil.

The invention has the beneficial effects that:

1. solves the problem that the single product aldol condensation reaction is difficult to realize multiple condensation to meet the required carbon chain length.

2. The length of the hydrocarbon carbon chain is determined by the coupling condition of catalytic pyrolysis oxygen-containing micromolecules, and the reasonable control of the carbon chain can be realized by regulating and controlling the components of pyrolysis gas.

3. Compared with the conventional method for generating the power mixed fuel by the aldol condensation-hydrogenation reaction, the reaction time of the one-step C-C coupling hydrogenation reaction can be controlled to be 20-60min, and the conventional method for generating the power mixed fuel is about 12 hours, so that the reaction time is greatly shortened.

4. The whole experiment is continuous and uninterrupted, the separation of the catalyst and the rectification of the product are not needed, the cost is greatly saved, and the method can directly realize that the alkane and the aromatic hydrocarbon in the ranges of gasoline, kerosene and diesel oil are selectively obtained by taking the biomass as the raw material.

5. The method can directly realize that the biomass is used as the raw material to selectively obtain alkane and aromatic hydrocarbon in the range of gasoline, kerosene and diesel, the carbon yield of oxygen-containing small molecular compounds is above 80 percent at most, and the carbon yield of alkane and aromatic hydrocarbon is above 65 percent at most, compared with the traditional method for preparing bio-oil by pyrolyzing the biomass, the method has the advantage that the hydrocarbon yield is improved by 40-60 percent, and the method is a green route for preparing excellent liquid energy substitutes by using the biomass as the raw material.

Drawings

FIG. 1 is a flow chart of an implementation method;

FIG. 2 analysis of results of different biomass sources for producing power fuels;

FIG. 3 analysis of the effect of metal oxide catalyst species on the yield of small molecular oxygen-containing compounds;

FIG. 4 analysis of the effect of bifunctional catalyst species on hydrocarbon yield.

FIG. 5 analysis of influence of pyrolysis temperature on yield of small molecular compounds containing oxygen;

FIG. 6 analysis of influence of catalytic temperature on yield of oxygen-containing small molecule compound

FIG. 7 analysis of the effect of reactor pressure on hydrocarbon yield;

FIG. 8 is a graph showing the effect of the temperature of the C-C coupled hydrogenation reaction on the yield of hydrocarbon compounds;

FIG. 9 analysis of the effect of bifunctional catalyst support species on hydrocarbon compound yield.

Detailed Description

The present invention will be further explained with reference to the following examples and the accompanying drawings, which are only illustrative and not intended to limit the scope of the present invention.

As shown in figure 1, the invention provides a method for preparing C through biomass catalytic pyrolysis and C-C coupling hydrogenation grading₆～C₁₈A method of powering a fuel in a fuel cell,the method comprises the following steps:

the biomass is subjected to catalytic pyrolysis in a two-section pyrolysis reactor, and pyrolysis gas is catalyzed by a metal oxide catalyst at the temperature of 300-460 ℃ to generate an oxygen-containing micromolecule compound; carrying out one-step C-C coupling hydrogenation reaction on the oxygen-containing small molecule mixed gas in a fixed bed continuous reactor to generate alkane and aromatic hydrocarbon, wherein the pressure in the reactor is 5-7 MPa, the temperature is 300-375 ℃, the catalyst is a supported metal dual-function catalyst, the hydrogen flow rate is 100-300 mL/min, and the reaction time is 20-60 min; and (3) carrying out fractional condensation on the final product in a reflux condenser, wherein the temperature of the reflux condenser is respectively 10-20 ℃, 10-0 ℃ and-30-10 ℃, and finally separating the final product into gasoline, kerosene and diesel oil.

Wherein the supported metal bifunctional catalyst is prepared by an isometric impregnation method or a coprecipitation method.

The process of the isometric impregnation method is as follows: firstly, adding soluble salt solution of A into a preformed carrier X according to a metering ratio, soaking in a medium volume, standing for 12 hours, then placing into a drying oven, drying for 24 hours at 110 ℃, and then calcining for 4 hours at 550 ℃ to obtain the catalyst meeting the requirements.

The coprecipitation process is as follows: firstly, adding soluble salt solution A into suspension of preformed carrier X according to a metering ratio, magnetically stirring for 3h at 180 ℃, taking out the obtained precipitate by using a centrifugal machine, drying for 24h at 110 ℃ in a drying box, and calcining for 4h at 550 ℃ to prepare the catalyst meeting the requirement.

Preferably, the calcined material is reduced at 450 ℃ using a reducing gas (10% H)₂And 90% N₂) The reduction was carried out for 6h at a flow rate of 20mL/min to obtain a catalyst which could be used directly.