CN108102683B

CN108102683B - Preparation method of branched alkane in range of renewable dodecyl alcohol and aviation kerosene

Info

Publication number: CN108102683B
Application number: CN201611043616.2A
Authority: CN
Inventors: 李宁; 盛雪茹; 张涛; 李广亿; 王爱琴; 王晓东; 丛昱
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2016-11-24
Filing date: 2016-11-24
Publication date: 2020-11-03
Anticipated expiration: 2036-11-24
Also published as: CN108102683A

Abstract

The invention relates to a preparation method of branched alkane in the range of biomass lauryl alcohol and aviation kerosene. The invention is divided into two parts: 1) in a first catalyst bed layer of a fixed bed continuous reactor, carrying out condensation reaction on mesityl oxide, diacetone alcohol, methyl isobutyl carbinol or a mixture of two or more of the compounds under the catalysis of an acid catalyst, an alkali catalyst, a metal-doped solid acid catalyst or a metal-doped solid alkali catalyst to obtain an oxygen-containing organic compound with a carbon chain length of 12; 2) on the second catalyst bed layer of the fixed bed continuous reactor, the condensation product generated by the first catalyst bed layer and unreacted hydrogen are subjected to hydrogenation reaction at a lower reaction temperature under the promotion of a metal catalyst to obtain the dodecanol.

Description

Preparation method of branched alkane in range of renewable dodecyl alcohol and aviation kerosene

Technical Field

The invention relates to a preparation method of branched alkane in the range of renewable dodecanol and aviation kerosene, which specifically comprises the following two steps: 1) in a first catalyst bed layer of a fixed bed continuous reactor, performing condensation reaction on a lignocellulose biomass platform compound of mesityl oxide, diacetone alcohol, methyl isobutyl carbinol or a mixture of two or more of the compounds and hydrogen under the promotion of an acid catalyst, an alkali catalyst, a metal-doped solid acid catalyst or a metal-doped solid alkali catalyst to obtain an oxygen-containing organic compound with a carbon chain length of 12; 2) on a second catalyst bed layer of the fixed bed continuous reactor, the oxygen-containing organic compound with the carbon chain length of 12 generated by the first catalyst bed layer can respectively obtain reproducible dodecanol or branched alkane with the carbon chain length of 12 by hydrogenation or hydrodeoxygenation under the promotion of the supported metal A/X type bifunctional catalyst. The dodecanol obtained by the method can be used as an intermediate for synthesizing a surfactant sodium dodecyl sulfate or sodium dodecyl benzene sulfonate, and the branched alkane with the carbon chain length of 12 obtained by the method can be mixed with the traditional aviation kerosene for use so as to relieve the dependence degree of China on imported crude oil. Compared with the reported work, the work directly synthesizes the branched alkane in the range of dodecanol or aviation kerosene by using the continuous reactor double-bed catalyst and hydrogen as raw materials under relatively mild conditions, wherein the branched alkane is formed by using mesityl oxide, diacetone alcohol, methyl isobutyl carbinol or a mixture of two or more of the compounds and the hydrogen, and has the advantages of simple process, high efficiency, energy conservation and the like.

Background

In recent years, energy and environmental issues have attracted considerable attention, and the work of synthesizing fuels and energy chemicals from renewable, carbon dioxide-neutral biomass has received high attention from countries throughout the world. Gasoline, diesel oil and aviation kerosene are transportation fuels with huge international demand at present. At present, gasoline, diesel oil and aviation kerosene are mainly prepared from crude oil by processes of rectification, cracking, reforming and the like, and have non-regenerability. In addition, gasoline, diesel oil and aviation fuel obtained from fossil energy can emit extra carbon dioxide to the atmosphere in the using process, so that the greenhouse effect is caused. Therefore, from the aspects of sustainable development, environmental protection, and the like, there is a strong need for the development of new technologies for producing gasoline, aviation kerosene, and diesel oil by catalytic conversion using renewable, carbon dioxide-neutral biomass as a raw material. On the other hand, fatty alcohols are an important class of fine chemicals and are widely used in the preparation of products such as surfactants, perfumes, cosmetics and the like. According to the number of carbon atoms, the fatty alcohol is divided into low-carbon fatty alcohol, medium-carbon fatty alcohol and high-carbon fatty alcohol. Wherein the C-fatty alcohol is C₁₂-C₁₄The aliphatic alcohol (2) is a main raw material of a detergent surfactant. Lignocellulose is the main component of agricultural and forestry waste, and has the advantages of low price and wide source compared with other forms of biomass. Therefore, the production of gasoline, aviation kerosene or fine chemicals from lignocellulose has been vigorously developed in recent years and has become an important research direction in the international catalytic refining of biomass.

Currently, biomass dodecanol is mainly obtained by hydrogenating palm oil. The raw materials have limited sources and high prices, are not suitable for large-scale production, and need to develop a renewable dodecanol synthesis technology taking cheap lignocellulose as raw materials. The international existing lignocellulose aviation fuel synthesis technology is mainly based on a platform compound, an aviation kerosene precursor with the carbon chain length of 8-16 is obtained through a carbon-carbon coupling reaction, and then the aviation kerosene precursor is subjected to hydrodeoxygenation reaction to synthesize the alkane in the aviation kerosene range. The process is complex and the equipment investment is large. In the two-step reaction, different reactants need to be heated and the product needs to be cooled repeatedly, so that the energy consumption is high. The separation of the catalyst and the rectification of the product have higher cost. Therefore, we hoped to find a way for biomass platform compounds to synthesize aviation kerosene range alkanes and fatty alcohols in one step.

In the patent, propylidene acetone, diacetone alcohol or a mixed feed of propylidene acetone and diacetone alcohol is used as a raw material, and propylidene acetone and diacetone alcohol can be obtained by self-condensation starting from acetone obtained by fermenting biomass lignocellulose through acetone-butanol-ethanol (ABE). The process is technically mature. Compared with methyl isobutyl ketone, propylidene acetone and diacetone alcohol are products of acetone self condensation, and the synthesis process is simpler and the cost is lower. The methyl isobutyl carbinol is a byproduct for synthesizing the methyl isobutyl ketone by taking acetone as a raw material, is also a byproduct in the process of synthesizing the dodecanol, and has relatively low price at present.

In a first catalyst bed layer of a fixed bed continuous reactor, a biomass platform compound of mesityl oxide, diacetone alcohol, methyl isobutyl carbinol or a mixture of two or more of the compounds and hydrogen are subjected to a self-condensation reaction under the catalysis of an acid catalyst, an alkali catalyst, a metal-doped solid acid catalyst or a metal-doped solid alkali catalyst to obtain an oxygen-containing organic compound with the carbon number of 12; 2) on a second catalyst bed layer of the fixed bed continuous reactor, a condensation product generated by the first catalyst bed layer is promoted by the loaded metal A/X type bifunctional catalyst to obtain dodecanol through a hydrogenation reaction or obtain branched alkane in the range of aviation kerosene through a hydrodeoxygenation reaction. In the whole process, the target product is directly obtained by taking the hydrogen and the mixture of two or more of the compounds of the isopropyl idene acetone, the diacetone alcohol and the methyl isobutyl carbinol as raw materials, so that the separation of the catalyst and the product is avoided, the distribution of the product can be adjusted by adjusting the temperature of the catalyst of the second bed layer, the chemical integration is realized, and the industrial continuous production of the dodecanol and the aviation kerosene in the future is facilitated.

Disclosure of Invention

The invention aims to provide a novel, simple and efficient synthesis route for preparing renewable branched alkane in the range of dodecanol or aviation kerosene from lignocellulose derived compounds.

The invention is realized by the following technical scheme:

branched alkanes in the dodecanol or jet fuel range are synthesized directly using a continuous reactor dual bed catalyst under relatively mild conditions.

1) In a first catalyst bed layer of a fixed bed continuous reactor, a biomass platform compound of mesityl oxide, diacetone alcohol, methyl isobutyl carbinol or a mixture of two or more of the compounds and hydrogen are subjected to condensation reaction under the catalysis of an acid catalyst, an alkali catalyst, a metal-doped solid acid catalyst or a metal-doped solid alkali catalyst to obtain an oxygen-containing organic compound with the carbon number of 12; in this patent, mesityl oxide, diacetone alcohol or methyl isobutyl carbinol or a mixture thereof is used as a raw material, and mesityl oxide and diacetone alcohol can be obtained by self aldol condensation starting from acetone obtained by fermenting biomass lignocellulose through acetone-butanol-ethanol (ABE). The methyl isobutyl carbinol is a byproduct in the reaction process of synthesizing methyl isobutyl ketone by taking acetone as a raw material, and is also a byproduct in the process of synthesizing dodecanol.

2) On a second catalyst bed layer of the fixed bed continuous reactor, the oxygen-containing organic compound with the carbon number of 12 and unreacted hydrogen generated by the first catalyst bed layer are promoted by the loaded metal A/X type bifunctional catalyst to obtain dodecanol through hydrogenation or obtain branched alkane with the carbon chain length of 12 in the aviation kerosene range through hydrodeoxygenation reaction.

The acid catalyst in the first catalyst bed layer is one or a mixture of more than two of the following solid acids: acidic resins (e.g., Amberlyst-15, Amberlyst-16, Amberlyst-36, Amberlyst-45, Amberlyst-70), acidic molecular sieves (e.g., H-ZSM-5, H-. beta., H-MOR, H-Y, etc.), phosphorylated metal oxides (e.g., phosphorylated zirconia, phosphorylated niobia, etc.), acidic metal oxides (e.g., niobia, tantalum oxide, montmorillonite K-10, KSF, etc.);

the alkali catalyst in the first catalyst bed layer is one or a mixture of more than two of the following solid alkali: the solid base comprises a basic metal oxide (e.g., MgO, CaO, SrO, La)₂O₃、CeO₂Etc.) basic metal composite oxides (such as: magnesium aluminum hydrotalcite, lithium aluminum hydrotalcite, KF/Al with the carrying amount of 10-60 wt%₂O₃MgO-ZrO having an Mg/Zr atomic number ratio of 1 to 20₂Etc.), basic molecular sieves (e.g.: Na-Y, Na-ZSM-5, Na-MOR, Na-MCM-41, etc.), basic ion exchange resins (e.g.: dowex 1X 4, Dowex 1X 2, Amberlite IRA-900, Amberlite IRA-400, etc.);

the metal-doped solid acid in the first catalyst bed layer is one or a mixture of more than two of cobalt, nickel, copper, silver, palladium, platinum, ruthenium, iridium and rhodium-doped solid acid.

The metal-doped solid alkali in the first catalyst bed layer is one or a mixture of more than two of cobalt, nickel, copper, silver, palladium, platinum, ruthenium, iridium and rhodium-doped solid alkali.

In the second catalyst bed layer, the supported metal bifunctional A/X type catalyst is used as the second catalyst bed layer to directly carry out hydrogenation or hydrodeoxygenation on a condensation reaction product of two or more than two of mesityl oxide, diacetone alcohol, methyl isobutyl carbinol or a mixture of the two or more than two of the compounds; the carrier X is one or a mixture of more than two of the following substances: SiO as composite carrier of active carbon, silicon oxide and silicon-aluminium₂-Al₂O₃(silicon to aluminum ratio of 0.01-100), molecular sieves (e.g., H-Y, HZSM-5, H β, HMOR, etc.), phosphorylated metal oxides (e.g., phosphorylated zirconium oxide, phosphorylated niobium oxide, phosphorylated tantalum oxide, etc.), acidic metal oxides (e.g., niobium oxide, titanium oxide, tantalum oxide, etc.); the active component A is one or more than two of Fe, Co, Ni, Cu, Pt, Pd, Ru, Ir and Rh; the mass fraction of the active component A in the catalyst is 1-50% (preferably 30-50%). (ii) a

The conditions of the fixed bed reactor were: when preparing dodecanol, the temperature of the first bed catalyst is between 100 and 500 ℃ (200 and 400 ℃ is preferred), the temperature of the second bed catalyst is between 50 and 250 ℃ (60 and 200 ℃ is preferred), the pressure of reaction hydrogen is between 0.1 and 10.0MPa (0.1 and 1.0MPa is preferred), and the mass space velocity of raw materials/first bed catalyst is between 0.1 and 10.0h^-1(preferably 0.1-5 h)^-1) The mass space velocity of the raw material/second bed layer catalyst is 0.1-10.0h^-1(preferably 0.1-5 h)^-1)H₂The molar ratio to the substrate starting material is from 1 to 800 (preferably from 1 to 200).

When preparing paraffinic hydrocarbon in the aviation kerosene range, the temperature of the fixed bed reactor is between 100 and 500 ℃ (preferably 200 and 400 ℃), the pressure of reaction hydrogen is between 0.1 and 10.0MPa (preferably 0.1 and 1.0MPa), and the mass space velocity of the raw material/first bed catalyst is between 0.1 and 10.0h^-1(preferably 0.1-5 h)^-1) The mass space velocity of the raw material/second bed layer catalyst is 0.1-10.0h^-1(preferably 0.1-5 h)^-1)H₂The molar ratio to the substrate starting material is from 1 to 800 (preferably from 1 to 200).

The invention is divided into two parts: 1) in a first catalyst bed layer of a fixed bed continuous reactor, carrying out condensation reaction on mesityl oxide, diacetone alcohol, methyl isobutyl carbinol or a mixture of two or more of the compounds under the catalysis of an acid catalyst, an alkali catalyst, a metal-doped solid acid catalyst or a metal-doped solid alkali catalyst to obtain an oxygen-containing organic compound with a carbon chain length of 12; 2) on the second catalyst bed layer of the fixed bed continuous reactor, the condensation product generated by the first catalyst bed layer and unreacted hydrogen are subjected to hydrogenation reaction at a lower reaction temperature under the promotion of a metal catalyst to obtain the dodecanol. In addition, on the second catalyst bed layer of the fixed bed continuous reactor, the condensation product generated by the first catalyst bed layer and unreacted hydrogen can also be subjected to hydrodeoxygenation reaction at the same temperature as the condensation reaction under the promotion of a metal catalyst to obtain branched alkane with the carbon chain length of 12. The lauryl alcohol obtained by the method can be synthesized into the surfactant sodium dodecyl sulfate by sulfonation, and also can be dehydrated to obtain dodecene which is one of main raw materials for synthesizing the main component sodium dodecyl sulfate of the laundry. The branched alkane with the carbon chain length of 12, which is obtained by the method, can be used as a potential substitute of aviation kerosene or diesel oil;

through the steps, the branched alkane in the range of dodecanol or aviation kerosene can be selectively obtained by directly taking the isopropyl idene acetone, the diacetone alcohol, the methyl isobutyl carbinol or the mixture of two or more of the compounds and hydrogen as raw materials, the yield is more than 70%, and the selectivity is high. The method is a novel efficient, green and simple synthetic route for preparing branched alkane in the range of fatty alcohol or aviation kerosene by taking a platform compound derived from lignocellulose as a raw material.

The branched alkane with the carbon chain length of 12 in the range of the aviation kerosene obtained by the method can become a potential substitute of the existing aviation kerosene or diesel oil; the dodecanol obtained by the method can be used for synthesizing raw materials of biomass-based surfactant sodium dodecyl sulfate, sodium dodecyl benzene sulfonate and the like.

Drawings

FIG. 1 is a GC-MS spectrum of the self-polymerized product of mesityl oxide;

FIG. 2 is a GC-MS spectrum of the hydrogenation of the self-polymerization product of mesityl oxide;

FIG. 3 is a GC spectrum of the self-polymerized product of mesityl oxide;

FIG. 4 is a GC spectrum of hydrodeoxygenation of a self-polymerized product of mesityl oxide;

FIG. 5 GC spectrum of hydrogenation of the polymerization product of mesityl oxide.

Detailed Description

The invention will now be illustrated by means of specific examples, without restricting its scope to these examples.

Examples 1 to 14

1. Preparation of the catalyst:

1) preparation of solid acid catalyst: nafion and Amberlyst resins, Y-type molecular sieves, montmorillonite K-10 and KSF are commercial catalyst products that are purchased directly.

The phosphorylated zirconium oxide (ZrP) catalyst is prepared by mixing 1mol/L zirconium oxychloride and ammonium dihydrogen phosphate aqueous solution according to the volume ratio of 2:1, repeatedly washing and filtering the obtained precipitate, drying at 120 ℃ for 10h, and then roasting at 400 ℃ for 4 h.

2) Preparation of solid base catalyst: the alkaline earth oxides (MgO, CaO, SrO) and the rare earth oxides (La2O3, CeO2) are respectively obtained by calcining the corresponding nitrates for 8h under the N2 atmosphere.

The magnalium hydrotalcite is prepared by dissolving 0.093mol of Mg (NO3) 2.6H 2O and 0.0465mol of Al (NO3) 3.9H 2O in 100ml of water, dropwise adding 0.219mol of NaOHA and 0.0565mol of Na2CO3 in 100ml of water bath at 70 ℃, continuously stirring and aging overnight after dropwise adding, filtering and washing, drying overnight at 80 ℃, and calcining for 8H at 450 ℃ to obtain magnalium mixed oxide. The lithium aluminum hydrotalcite is prepared by dropwise adding 125mL of Al (NO3) 3.9H 2O (0.4mol/L) water solution into 300mL of LiOH H2O (1.5mol/L) and Na2CO3(0.08mol/L) mixed solution which is continuously stirred at room temperature. After the addition, the mixture was aged at 75 ℃ for 24 hours. Filtering, washing, drying at 80 ℃ overnight, and calcining at 500 ℃ for 8h to obtain the lithium-aluminum mixed oxide.

KF/Al2O3 gamma-Al 2O3 was immersed in KF solution by an equal volume immersion method for 12h, dried at 80 ℃ to obtain KF/gamma-Al 2O3 with a theoretical mass loading of 23%.

MgO-ZrO 2A 25 wt% NaOH solution was added dropwise to a 1L solution of 50.9g of Mg (NO3) 2.6H 2O and 4.04g of ZrO (NO3)2 to a pH of 10, aged at room temperature for 72 hours, filtered and washed, dried at 80 ℃ overnight, and calcined at 600 ℃ for 8 hours. All solid base catalysts were pretreated for 2h under an atmosphere of N2 before use.

3) Metal-doped solid acid:

take HY molecular sieve doped with metal as an example. Respectively preparing metal salt solution (one or more than two of cobalt nitrate, nickel nitrate, copper nitrate, palladium nitrate, platinum chloride, ruthenium chloride, iridium chloride and the like) with the mass fraction of 5 wt%, diluting according to the saturated water absorption capacity of the carrier, impregnating the HY molecular sieve in equal volume, standing overnight, drying at 80 ℃, roasting at 500 ℃ for 2h, and reducing the roasted catalyst in situ in a fixed bed at 500 ℃ for 2h by using hydrogen.

4) Metal-doped solid base:

take metal doped magnalium hydrotalcite catalyst as an example. Dissolving 0.093mol Mg (NO3) 2.6H 2O and 0.0465mol Al (NO3) 3.9H 2O in 100ml of water, dripping a salt solution (one or more of cobalt nitrate, nickel nitrate, copper nitrate, palladium nitrate, platinum chloride, ruthenium chloride, iridium chloride and the like) containing 0.001mol to 0.01mol of metal into the mixed solution, dripping 100ml of an aqueous solution of 0.219mol of NaOH and 0.0565mol of Na2CO3 into the solution under the condition of 70 ℃ water bath, continuing stirring and aging overnight after finishing dripping, filtering and washing, drying at 80 ℃ overnight, and calcining at 450 ℃ for 8H to obtain the mixed oxide.

5) Preparation of hydrodeoxygenation catalyst:

an isometric immersion method: respectively preparing ferric nitrate, cobalt nitrate, nickel nitrate and copper nitrate solutions with mass fractions of 5 wt%, diluting according to saturated water absorption capacity of a carrier, adding one or more of the solutions into silicon dioxide for isovolumetric impregnation, standing overnight, drying at 80 ℃, roasting at 500 ℃ for 2h, and reducing the roasted catalyst in situ in a fixed bed at 500 ℃ for 2h by using hydrogen. (see Table 1, examples 1-4). Respectively preparing platinum chloride, palladium nitrate and ruthenium chloride solutions with mass fractions of 5 wt%, diluting according to the saturated water absorption capacity of a carrier, adding one or more of the solutions into an H-beta molecular sieve for isovolumetric impregnation, standing overnight, drying at 80 ℃, roasting at 500 ℃ for 2 hours, and reducing the roasted catalyst in situ in a fixed bed at 500 ℃ for 2 hours by using hydrogen. (see Table 1, examples 5-7).

Respectively preparing nickel nitrate solution with the mass ratio of 5 wt%, correspondingly diluting according to the saturated water absorption capacity of the carrier, adding one of H-ZSM-5, H-MOR, silicon-aluminum composite carrier, H-beta molecular sieve and alumina, standing for 2H, drying at 120 ℃ overnight, roasting at 500 ℃ for 2H in air, and reducing the roasted catalyst in situ for 2H by using hydrogen at 500 ℃ in a fixed bed. (see Table 1, examples 8-12).

A complex impregnation method: respectively preparing mixed solution (the molar weight of ethylene glycol and salt ions is equal) of nickel nitrate ethylene glycol and water with the mass fraction of 5 wt%, respectively adding one of silicon dioxide, H-ZSM-5, H-MOR, a silicon-aluminum composite carrier, an H-beta molecular sieve and alumina into the mixed solution in an equal volume for impregnation, standing the impregnated solution overnight, drying the impregnated solution at 80 ℃, roasting the impregnated solution for 2 hours at 500 ℃, and reducing the roasted catalyst for 2 hours in situ by using hydrogen in a fixed bed at 500 ℃. (see Table 1, example 13)

Deposition and precipitation method: respectively preparing 0.0175M nickel nitrate solution, and dividing the nickel nitrate solution into two parts A and B in equal volume, adding one of silicon dioxide, H-ZSM-5, H-MOR, silicon-aluminum composite carrier, H-beta molecular sieve and alumina and a proper amount of concentrated nitric acid into the A, adding 0.0525M urea into the B, slowly dripping the B into the A in a water bath at 80 ℃, heating to 90 ℃, stirring for 10H, filtering, washing, drying at 80 ℃ overnight, roasting for 2H in air at 500 ℃, and reducing the roasted catalyst for 2H in situ by using hydrogen at 500 ℃ in a fixed bed. (see Table 1, examples 14-18)

TABLE 1 Supported Metal A/X type bifunctional catalyst

2 self-condensation reaction: in a fixed bed reactor, 1.0g of catalyst was loaded into a reaction tube, the hydrogen pressure in the reactor was maintained at 0.6MPa, the hydrogen flow rate was 150mL/min, and propylidene acetone was pumped into the reactor at 0.05mL/min using a high performance liquid chromatography pump. The reaction results are shown in tables 2 and 3.

TABLE 2 self-condensation of propylidene acetone

As can be seen from Table 2, the self-polymerization activity of propylidene acetone is not satisfactory in the presence of a solid acid or an alkaline catalyst which is not doped with a metal. When noble metals are doped on acid or base catalysts (examples 19-35), twelve-carbon ketones, alcohols, can be formed. Wherein, the activity is better when the Mg-Al hydrotalcite is doped with Pd.

TABLE 3 target product formula of self-condensation reaction

Examples 36 to 41

Taking palladium-doped magnesium aluminum hydrotalcite (Pd-MgAl-HT) as an example, and carrying out optimization exploration on reaction conditions.

1) Effect of the Palladium/magnesium molar ratio on the yield of the self-condensation reaction of Propylideneacetone

TABLE 4 influence of catalyst quality fraction on product yield

As can be seen from Table 4, the overall product yield is highest when the molar ratio of palladium/magnesium is 0.02.

Examples 42 to 46

2) Effect of different reaction temperatures on the yield of the self-condensation reaction of mesityl oxide

TABLE 5 Effect of different reaction temperatures on product yield

As can be seen from Table 5, when the reaction temperature is 250 ℃ and 280 ℃, the yield of the product B is higher and the sum of the yields is higher.

Examples 47 to 50

3) Influence of different hydrogen pressures on the yield of the self-condensation reaction of mesityl oxide

TABLE 6 Effect of different hydrogen pressures on product yield

As can be seen from Table 6, the total yield of the objective B, C was high at a hydrogen pressure of 0.6 MPa.

Examples 51 to 57

4) Effect of different feed Components on yield

TABLE 7 Effect of different feed Components on product yield

As can be seen from Table 6, the change of the molar ratio of mesityl oxide to diacetone alcohol has little influence on the total yield of B, C, which is favorable for the industrial direct condensation of acetone to the mixture of mesityl oxide and diacetone alcohol without separation. In addition, B and C can be obtained in higher yield by using the methyl isobutyl carbinol (product D) which is a byproduct in the reaction. The total yield of B, C can be further improved by recycling the product D in actual production.

3. And (3) hydrogenation deoxidation reaction:

examples 58 to 75

1) Effect of different catalysts on the Hydrodeoxygenation reaction

In a fixed bed reactor, 1.0g of mesityl oxide self-condensation catalyst (taking Pd-MgAl-HT as an example) is used as a first catalyst bed layer, 1.5g of hydrodeoxygenation catalyst is used as a second catalyst bed layer and is filled into a reaction tube, the pressure in the reactor is kept at 0.6MPa, the hydrogen flow rate is 150mL/min, the reaction temperature is 280 ℃, and the mesityl oxide is pumped into the reactor by a high performance liquid chromatography pump at 0.05 mL/min. The reaction results are shown in Table 9.

TABLE 8 target product formula for hydrodeoxygenation reaction

It can be seen from table 9 that under the reaction conditions, the selected catalyst can achieve hydrodeoxygenation of the product. The main product F obtained by hydrodeoxygenation was an aviation kerosene range branched paraffin. The by-product E can be used as renewable gasoline.

TABLE 9 Effect of different A/X type bifunctional catalysts on the Hydrodeoxygenation reaction Activity

Examples 76 to 80

2) Effect of different temperatures on the Hydrodeoxygenation reaction

In a fixed bed reactor, 1.0g of mesityl oxide self-condensation catalyst (taking Pd-MgAl-HT as an example) is used as a first catalyst bed layer, 1.5g of hydrodeoxygenation catalyst 5% Cu/SiO2 is used as a second catalyst bed layer and is filled into a reaction tube, the pressure in the reactor is kept at 0.6MPa, the hydrogen flow rate is 150mL/min, and the mesityl oxide is pumped into the reactor by a high performance liquid chromatography pump at 0.05 mL/min. The reaction results are shown in Table 10.

TABLE 10 Effect of different temperatures on the hydrodeoxygenation reactivity

As can be seen from table 10, the oxygen-containing compound was not completely hydrodeoxygenated at a temperature of less than 250 c, and was completely hydrodeoxygenated at a temperature of 250 c or more. Wherein the yield is highest at 250 ℃ and 280 ℃.

4. Hydrogenation reaction:

examples 81 to 92

1) Effect of different catalysts on hydrogenation reactions

In a fixed bed reactor, 1.0g of mesityl oxide self-condensation catalyst (taking Pd-MgAl-HT as an example) is used as a first catalyst bed layer (the bed layer temperature is 250 ℃) and 1.5g of hydrogenation catalyst is used as a second catalyst bed layer (the bed layer temperature is 100 ℃) and is filled into a reaction tube, the pressure in the reactor is kept at 0.6MPa, the hydrogen flow rate is 150mL/min, and the mesityl oxide is pumped into the reactor by a high performance liquid chromatography pump at 0.05 mL/min. The reaction results are shown in Table 11.

TABLE 11 Effect of different A/X type bifunctional catalysts on hydrogenation reaction Activity

As can be seen from Table 11, the activated carbon has a better reactivity with the palladium, ruthenium and iridium catalysts, and can completely hydrogenate the ketones formed in the first bed to alcohols. The product B can be used as a raw material for synthesizing a surfactant sodium dodecyl sulfate or sodium dodecyl benzene sulfonate, and the product D can be used as a mineral flotation agent and can be recycled to continuously improve the yield of the product B.

Examples 93 to 97

2) Effect of different temperatures on hydrogenation reactions

In a fixed bed reactor, 1.0g of mesityl oxide self-condensation catalyst (taking Pd-MgAl-HT as an example) is used as a first catalyst bed layer (the bed layer temperature is 250 ℃), 1.5g of hydrogenation catalyst is used as a second catalyst bed layer, 5 percent Ru/C is loaded into a reaction tube, the pressure in the reactor is kept at 0.6MPa, the hydrogen flow rate is 150mL/min, and the mesityl oxide is pumped into the reactor by a high performance liquid chromatography pump at 0.05 mL/min. The reaction results are shown in Table 12.

TABLE 12 Effect of different temperatures on hydrogenation reactivity

As can be seen from Table 12, the product in the first bed can be completely hydrogenated to alcohols at temperatures in the range of 80-120 ℃ and cannot be completely hydrogenated at too low or too high a temperature.

By way of the above examples, a detailed course of a series of catalyst preparations (examples 1-35) is detailed and a thorough discussion of their hydrodeoxygenation reactivity of oxygenated precursors in the lignocellulose-based gasoline, aviation kerosene range, under the conditions given above (examples 36-80), yields of C12 alkanes (product F) were obtained with an overall yield of about 73%. They can be used as novel liquid hydrocarbon fuel directly or added into the existing gasoline and aviation kerosene in a certain proportion for use. On the other hand, we also explored the hydrogenation activity of the oxygenate with carbon chain length 12 (product B, C) produced in the first bed, and obtained an overall yield of C12 alcohol (product C) of about 73% under the conditions given above (examples 81-97). The C12 fatty alcohol (product C) can be used as raw material for synthesizing biomass-based surfactant.

The liquid fuel produced by the invention can become potential substitutes of the existing gasoline and aviation kerosene and precursors of biomass surfactants.

Claims

1. A process for the preparation of branched alkanes in the renewable dodecanol and jet fuel ranges, characterized in that:

reacting in a fixed bed continuous reactor sequentially filled with a first catalyst bed layer and a second catalyst bed layer; under the catalysis of a double-bed catalyst, one or more than two of mesityl oxide, diacetone alcohol and methyl isobutyl carbinol are mixed with hydrogen to directly synthesize dodecanol or branched alkane with a carbon chain length of 12 in the range of aviation kerosene;

1) in a first catalyst bed layer of a fixed bed continuous reactor, carrying out condensation reaction on a mixture of one or more than two of mesityl oxide, diacetone alcohol and methyl isobutyl carbinol and hydrogen under the catalysis of an alkali catalyst and a metal-doped solid alkali catalyst to obtain an oxygen-containing organic compound with the carbon number of 12;

2) on a second catalyst bed layer of the fixed bed continuous reactor, the first catalyst bed layer generates an oxygen-containing organic compound with the carbon number of 12 and unreacted hydrogen, and the oxygen-containing organic compound and the unreacted hydrogen are promoted by a loaded metal catalyst A/X to obtain dodecanol through hydrogenation or obtain branched alkane in the range of aviation kerosene through hydrodeoxygenation;

in the step 1), the alkali catalyst is one or a mixture of more than two of the following solid alkali: the solid alkali comprises alkaline metal oxide, alkaline metal composite oxide, alkaline molecular sieve and alkaline ion exchange resin;

the metal-doped solid base catalyst in the step 1) is one or a mixture of more than two of the solid bases doped with palladium, silver, platinum, ruthenium, iridium and rhodium;

the mass doping amount of the metal in the metal-doped solid base catalyst in the step 1) is 0.01-20%;

the temperature of the first bed catalyst and the second bed catalyst is between 190 ℃ and 310 ℃.

2. The method of claim 1, wherein:

the alkaline metal oxide is MgO, CaO, SrO, La₂O₃、CeO₂One or more than two of them; the alkaline metal composite oxide is magnesium aluminum hydrotalcite, lithium aluminum hydrotalcite, KF/Al with the carrying amount of 10-60 wt%₂O₃MgO-ZrO having an Mg/Zr atomic number ratio of 1 to 20₂One or more than two of them; the alkaline molecular sieve is one or more than two of Na-Y, Na-ZSM-5, Na-MOR and Na-MCM-41; the basic ion exchange resin is one or more of Dowex1 × 4, Dowex1 × 2, Amberlite IRA-900 and Amberlite IRA-400.

3. The method of claim 1, wherein: the mass doping amount of the metal in the metal-doped solid base catalyst in the step 1) is 0.01-5%.

4. The method of claim 1, wherein:

in the step 2), a supported metal bifunctional A/X type catalyst is used as a second catalyst bed layer to directly carry out hydrogenation or hydrodeoxygenation on a condensation reaction product of one or more than two of mesityl oxide, diacetone alcohol and methyl isobutyl carbinol; the carrier X is one or a mixture of more than two of the following substances: SiO as composite carrier of active carbon, silicon oxide and silicon-aluminium₂- Al₂O₃Molecular sieves, phosphorylated metal oxides, acidic metalsAn oxide; the active component A is one or more than two of Fe, Co, Ni, Cu, Pt, Pd, Ru, Ir and Rh; the mass fraction of the active component A in the catalyst is 1-50%.

5. The method of claim 4, wherein: silicon-aluminum composite carrier SiO₂- Al₂O₃The silicon-aluminum ratio of (A) is between 0.01 and 100; the molecular sieve is one or more than two of H-Y, HZSM-5, H beta and HMOR; the phosphorylated metal oxide is one or more of phosphorylated zirconium oxide, phosphorylated niobium oxide and phosphorylated tantalum oxide; the acidic metal oxide is one or more of niobium oxide, titanium oxide and tantalum oxide; the mass fraction of the active component A in the catalyst is 30-50%.

6. The method of claim 1, wherein:

a fixed bed continuous reactor double-bed catalyst is adopted in the step 1) and the step 2); an alkali catalyst or a metal-doped solid alkali catalyst is used as a first catalyst bed layer to catalyze the condensation reaction of one or a mixture of more than two of mesityl oxide, diacetone alcohol and methyl isobutyl carbinol and hydrogen to obtain an oxygen-containing organic compound with a carbon chain length of 12 in high selectivity; taking the supported metal catalyst A/X as a second catalyst bed layer to directly carry out hydrogenation or hydrodeoxygenation on a condensation reaction product generated by the first catalyst bed layer to obtain reproducible dodecanol or aviation kerosene range branched paraffin; the conditions of the fixed bed reactor were: the temperature of the first bed catalyst and the second bed catalyst is between 190 and 310 ℃, the pressure of reaction hydrogen is between 0.1 and 10.0MPa, and the mass space velocity of the raw material/first bed catalyst is between 0.1 and 10.0h^-1The mass space velocity of the raw material/second bed layer catalyst is 0.1-10.0h^-1，H₂The molar ratio of the raw material to the substrate is 1-800.

7. The method of claim 6, wherein:

the conditions of the fixed bed reactor were: the pressure of reaction hydrogen is 0.1-1.0MPa, and the raw material/the first materialThe mass space velocity of the bed catalyst is 0.1-5h^-1The mass space velocity of the raw material/second bed layer catalyst is 0.1-5h^-1，H₂The molar ratio of the raw material to the substrate is 1-200.

8. The production method according to claim 1, 2, 3, 4, 5, 6 or 7, characterized in that:

the oxygen-containing organic compound with the carbon number of 12 refers to B, C in table 3 and one or a mixture of more than two of isomers and homologues thereof;

and (3) a product B:

；

and (3) a product C:

；

branched alkanes in the jet fuel range of 12 carbon atoms refer to product F in table 10 and one or a mixture of more than two of its isomers and homologues; and (3) a product F:

。

9. the method of claim 1 or 4, wherein:

the load type metal A/X type catalyst is prepared by adopting an isovolumetric impregnation, complex impregnation or deposition precipitation method,

the process of the isometric impregnation method is as follows: firstly, adding a soluble salt solution A into a preformed carrier X according to a metering ratio, soaking in a medium volume, standing for more than 6 hours, drying, and roasting at the temperature of 300-700 ℃ for 2-5 hours to prepare a roasted catalyst;

the complex impregnation process is as follows: firstly, dissolving soluble salt of A in an equimolar complexing agent, adding water to the same volume for impregnation, standing for more than 6 hours, drying, and roasting at the temperature of 300-700 ℃ for 2-5 hours to prepare a roasted catalyst;

the deposition precipitation process is as follows: firstly, adding a soluble salt solution A into a suspension of a preformed carrier X according to a metering ratio, and adding a corresponding precipitator under continuous stirring; aging for more than 2h, filtering, drying, and roasting at 300-700 ℃ for 2-5 h to obtain the roasted catalyst.

10. The method of claim 9, wherein: the load type metal A/X type catalyst adopts an isometric impregnation method in the preparation process: the roasting temperature is 400-600 ℃;

the supported metal A/X type catalyst is prepared by adopting a complex impregnation method, wherein the preparation method comprises the following steps: the roasting temperature is 400-600 ℃;

the preparation process of the supported metal A/X type catalyst adopts a deposition precipitation method: the roasting temperature is 400-600 ℃.