An isomerization depressant catalyst for producing bio-jet fuel and a method of using the same

Abstract

The present invention is applicable to the technical field of bio-jet fuel, and provides an isomerization depressant catalyst for producing bio-jet fuel and a method of using the same, wherein the hydroisomerization depressant catalyst is a refractory oxide carrier loaded with nickel, and the hydroisomerization depressant catalyst involves a Y-type molecular sieve containing a super cage structure as the refractory oxide carrier used. The present invention designs a supported transition metal catalyst for the high-cost supported precious metal and bulk rare earth metal catalysts, and the Y-type molecular sieve is selected as the carrier, which has the advantages of low cost and high reaction activity; the catalyst used is a reduced transition metal, which has a stronger tolerance to impurities than precious metals.

Description

Technical Field

[0001] The present invention belongs to the technical field of bio-jet fuel, and in particular relates to an isomerized degassing catalyst for producing bio-jet fuel and a method of using the catalyst. Background Art

[0002] With the continuous development of the world's aviation industry, the demand for aviation kerosene is increasing day by day. At present, with the reduction of global oil reserves and the fluctuation of oil prices, the problems of aviation energy safety and economy have become more prominent. In addition, the carbon dioxide produced by the combustion of aviation kerosene in aircraft is basically discharged into the stratosphere of the atmosphere, producing a strong greenhouse effect. Therefore, the aviation industry faces severe challenges in reducing carbon dioxide emissions. In order to cope with climate change, the development of alternative fuels, especially bio-jet fuel, is particularly important.

[0003] Biojet fuel, which is synthesized from animal and plant oils and fats using biomass organic matter such as ester biodiesel and hydrocarbon biodiesel, and is prepared using the hydroisomerization method, is an environmentally friendly fuel with the characteristics of a wide source of raw materials, zero carbon dioxide emissions, and being renewable. Its chemical structure is similar to that of petroleum-based jet fuel, and the two are miscible, making it one of the most promising substitutes for petroleum-based jet fuel in the future.

[0004] According to existing literature, in the production process of bio-jet fuel, the products of bio-raw materials after hydrodeoxygenation are mainly normal alkanes with carbon numbers of C15~C18. If these normal alkanes are to be converted into bio-jet fuel, they must undergo isomerization and cracking reactions to form iso-alkanes with carbon numbers of C9~C15. In this chemical reaction process, the ratio of isomerization and cracking reactions is required to be high. If there are too many cracking reactions, the yield of bio-jet fuel will be reduced; if the isomerization is insufficient, the freezing point requirements of bio-jet fuel cannot be met.

[0005] At present, the isomerization decondensation process of bio-jet fuel generally uses supported reduced precious metals Pt, Pd, Ru; bulk rare earth metals La, Ce catalysts, and the carriers used are usually ZSM-5, ZSM-12, ZSM-22, beta and other molecular sieves used alone or in combination. The reported catalysis all showed good hydrogenation activity, but there are problems such as high cost of precious metals and rare earth metals, and high cost of some molecular sieves. For this reason, we propose a isomerization decondensation catalyst for the production of bio-jet fuel and a method of using it. Summary of the invention

[0006] The object of the present invention is to provide an isomerization depressant catalyst for producing bio-jet fuel and a method for using the same, in order to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A isomerization degassing catalyst for producing bio-jet fuel, the catalyst is a refractory oxide carrier loaded with nickel, and the refractory oxide carrier used in the hydrogenation isomerization degassing catalyst is a Y-type molecular sieve containing a supercage structure.

[0009] Furthermore, the unit cell constant of the Y-type molecular sieve is 2.424~2.434nm.

[0010] Furthermore, the nickel content of the hydroisomerization degassing catalyst is 1-30wt%.

[0011] Furthermore, the nickel content of the hydroisomerization degassing catalyst is 10-25wt%.

[0012] Furthermore, the specific surface area of ​​the hydroisomerization degassing catalyst is 200-400m 2 / g, and the pore volume is 0.25~0.45ml / g.

[0013] A method for using an isomerization depressant catalyst for producing bio-jet fuel, using biomass organic matter as raw material, reacting the raw material with a hydrogenation isomerization depressant catalyst in a continuous fixed bed reactor under hydrogen conditions to obtain bio-jet fuel.

[0014] Furthermore, the hydroisomerization pour point depressant catalyst is used in a reduced state, and the reduced hydroisomerization pour point depressant catalyst includes an in-situ online pre-reduction before use or a catalyst prepared in a reduced state for use.

[0015] Furthermore, the hydrogenation conditions include: a hydrogen pressure of 1-10 MPa and a reaction temperature of 250-400°C.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] Compared with the existing bio-jet fuel isomerization decondensation method, the present invention designs a supported transition metal catalyst for the supported precious metal and bulk rare earth metal catalysts with relatively high costs. The Y-type molecular sieve is used as the carrier, which has the advantages of low cost and high reaction activity. The catalyst used is a reduced transition metal, which has a stronger tolerance to impurities than precious metals. Implementation

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail in conjunction with the following embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0020] An embodiment of the present invention provides an isomerization degassing catalyst for producing bio-jet fuel, wherein the catalyst is a refractory oxide carrier loaded with nickel, and the refractory oxide carrier used in the hydrogenation isomerization degassing catalyst is a Y-type molecular sieve containing a supercage structure.

[0021] As a preferred embodiment of the present invention, the unit cell constant of the Y-type molecular sieve is 2.424~2.434nm.

[0022] As a preferred embodiment of the present invention, the nickel content of the hydroisomerization degassing catalyst is 1-30wt%.

[0023] As a preferred embodiment of the present invention, the nickel content of the hydroisomerization degassing catalyst is 10-25wt%.

[0024] As a preferred embodiment of the present invention, the specific surface area of ​​the hydroisomerization degassing catalyst is 200-400m 2 / g, and the pore volume is 0.25~0.45ml / g.

[0025] A method for using an isomerization depressant catalyst for producing bio-jet fuel, using biomass organic matter as raw material, reacting the raw material with a hydrogenation isomerization depressant catalyst in a continuous fixed bed reactor under hydrogen conditions to obtain bio-jet fuel.

[0026] As a preferred embodiment of the present invention, the hydroisomerization pour point depressant catalyst is used in a reduced state, and the reduced hydroisomerization pour point depressant catalyst includes an in-situ online pre-reduction before use or a preparation in a reduced state for use.

[0027] As a preferred embodiment of the present invention, the hydrogen conditions include: a hydrogen pressure of 1-10 MPa and a reaction temperature of 250-400°C.

[0028] As a preferred embodiment of the present invention, the biomass organic matter is ester-based biodiesel and / or hydrocarbon-based biodiesel. Example

[0029] Using hydrocarbon biodiesel as raw material, Y-type molecular sieve loaded with 15wt% nickel is used as catalyst. The molecular sieve has a pore size of 4.87nm, a pore volume of 0.44ml / g, and a specific surface area of ​​388.4m 2 / g. The reaction was carried out in a continuous fixed bed reactor, and the catalyst was pre-reduced online in situ. The reaction temperature was 280°C, the hydrogen pressure was 4MPa, the hydrogen-to-oil ratio was 1000, and the mass space velocity was 2.0h -1 .

[0030] The reaction liquid had a yield of 96.8%, a conversion rate of 72.7%, a bio-jet fuel selectivity of 58.9%, and an isomerization rate of 40.5%.

[0031] The test showed that the density was less than 0.78ml / g and the freezing point was less than -40℃, which met the requirements of biojet fuel. Example

[0032] Using hydrocarbon biodiesel as raw material, Y-type molecular sieve loaded with 15wt% nickel is used as catalyst. The molecular sieve has a pore size of 4.87nm, a pore volume of 0.44ml / g, and a specific surface area of ​​388.4m 2 / g. The reaction was carried out in a continuous fixed bed reactor, and the catalyst was pre-reduced online in situ. The reaction temperature was 255°C, the hydrogen pressure was 4MPa, the hydrogen-to-oil ratio was 1000, and the mass space velocity was 0.5h -1 .

[0033] The reaction liquid had a yield of 91.6%, a conversion rate of 64.8%, a bio-jet fuel selectivity of 70.9%, and an isomerization rate of 53.5%.

[0034] The test showed that the density was less than 0.78ml / g and the freezing point was less than -40℃, which met the requirements of biojet fuel. Example

[0035] Using hydrocarbon biodiesel as raw material, Y-type molecular sieve loaded with 15wt% nickel is used as catalyst. The molecular sieve has a pore size of 4.87nm, a pore volume of 0.44ml / g, and a specific surface area of ​​388.4m 2 / g. The reaction was carried out in a continuous fixed bed reactor. The catalyst was pre-reduced in situ. The reaction temperature was 300°C, the hydrogen pressure was 4MPa, the hydrogen-to-oil ratio was 1000, and the mass space velocity was 5.0h -1 .

[0036] The reaction liquid had a yield of 99.8%, a conversion rate of 75.5%, a bio-jet fuel selectivity of 62.8%, and an isomerization rate of 35.4%.

[0037] The test showed that the density was less than 0.78ml / g and the freezing point was less than -40℃, which met the requirements of biojet fuel. Example

[0038] Using hydrocarbon biodiesel as raw material, Y-type molecular sieve loaded with 15wt% nickel is used as catalyst. The molecular sieve has a pore size of 4.87nm, a pore volume of 0.44ml / g, and a specific surface area of ​​388.4m 2 / g. The reaction was carried out in a continuous fixed bed reactor, and the catalyst was pre-reduced online in situ. The reaction temperature was 280°C, the hydrogen pressure was 8MPa, the hydrogen-to-oil ratio was 1000, and the mass space velocity was 2.0h -1 .

[0039] The reaction liquid had a yield of 92.5%, a conversion rate of 76.8%, a bio-jet fuel selectivity of 57.6%, and an isomerization rate of 43.2%.

[0040] The test showed that the density was less than 0.78ml / g and the freezing point was less than -40℃, which met the requirements of biojet fuel. Example

[0041] Using hydrocarbon biodiesel as raw material, Y-type molecular sieve loaded with 12wt% nickel as catalyst. The molecular sieve has a pore size of 4.87nm, a pore volume of 0.44ml / g, and a specific surface area of ​​388.4m 2 / g. The reaction was carried out in a continuous fixed bed reactor, and the catalyst was pre-reduced online in situ. The reaction temperature was 280°C, the hydrogen pressure was 4MPa, the hydrogen-to-oil ratio was 1000, and the mass space velocity was 2.0h -1 .

[0042] The reaction liquid had a yield of 98.6%, a conversion rate of 65.7%, a biojet fuel selectivity of 53.5%, and an isomerization rate of 42.6%.

[0043] The test showed that the density was less than 0.78ml / g and the freezing point was less than -40℃, which met the requirements of biojet fuel. Example

[0044] Using hydrocarbon biodiesel as raw material, Y-type molecular sieve loaded with 15wt% nickel is used as catalyst. The molecular sieve has a pore size of 6.87nm, a pore volume of 0.40ml / g, and a specific surface area of ​​360.6m 2 / g. The reaction was carried out in a continuous fixed bed reactor. The catalyst was pre-reduced in situ. The reaction temperature was 280°C, the hydrogen pressure was 4MPa, the hydrogen-to-oil ratio was 1000, and the mass space velocity was 2.0h -1 .

[0045] The reaction liquid had a yield of 97.2%, a conversion rate of 69.3%, a bio-jet fuel selectivity of 59.8%, and an isomerization rate of 38.5%.

[0046] The test showed that the density was less than 0.78ml / g and the freezing point was less than -40℃, which met the requirements of biojet fuel.

[0047] The above are only preferred embodiments of the present invention. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These should also be regarded as the protection scope of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. An isomerization depressant catalyst for producing bio-jet fuel, characterized in that: The catalyst is a refractory oxide carrier loaded with nickel, and the refractory oxide carrier used in the hydroisomerization decondensation catalyst is a Y-type molecular sieve containing a super cage structure; The unit cell constant of the Y-type molecular sieve is 2.424-2.434 nm; The nickel content of the hydroisomerization degassing catalyst is 10-25wt%; The specific surface area of ​​the hydroisomerization decondensation catalyst is 200-400m 2 / g, pore volume is 0.25~0.45ml / g; The method for using the isomerization depressant catalyst for producing bio-jet fuel is as follows: using biomass organic matter as raw material, reacting the raw material with the hydrogenation isomerization depressant catalyst in a continuous fixed bed reactor under hydrogen conditions to obtain bio-jet fuel; The hydroisomerization pour point depressing catalyst is used in a reduced state, and the reduced hydroisomerization pour point depressing catalyst includes in-situ online pre-reduction before use or preparation in a reduced state for use; The hydrogenation conditions include: a hydrogen pressure of 1-10 MPa and a reaction temperature of 250-400°C.