CN-122006799-A - Catalyst for preparing high-density special fuel from high-temperature coal tar, grading method and application thereof

CN122006799ACN 122006799 ACN122006799 ACN 122006799ACN-122006799-A

Abstract

The invention discloses a catalyst for preparing high-density special fuel from high-temperature coal tar, a grading method and application thereof, and belongs to the technical field of preparation of high-density special fuel. The catalyst consists of a hydrogenation protecting agent, a hydrogenation refining agent, a hydrocracking agent and a hydroisomerizing agent, sulfur, nitrogen, oxygen, metal impurities, olefin and the like of high-temperature coal tar are removed through catalyst grading of each bed layer in the reactor, aromatic hydrocarbon saturation, cracking and isomerization are carried out under proper process conditions, and finally coal tar is purified to improve the quality of oil products, so that the high-density special fuel is prepared. The catalyst has high catalytic efficiency on high-density special fuel prepared by hydrogenating high-temperature coal tar, high yield of the high-density special fuel, density of 901kg/m 3 , low Wen Ningdian-56 ℃ and heat value of 42.6MJ/kg, and the catalyst grading mode has excellent hydrogenation activity and stability, reduces cracking degree, increases saturated isomerization reaction and can obtain high-density special fuel with larger yield.

Inventors

LI ZHENRONG
WU XINGJIE
WANG LEI
LI XIN
DONG HONGYU
FENG SHUO
ZHAO LIANGFU

Assignees

中国科学院山西煤炭化学研究所

Dates

Publication Date: 20260512
Application Date: 20260121

Claims (10)

1. The catalyst for preparing the high-density special fuel from the high-temperature coal tar is characterized by comprising a hydrogenation protecting agent, a hydrogenation refining agent, a hydrocracking agent and a hydroisomerizing agent; the hydrogenation protective agent is bird nest type hydrogenation protective agent and Mo-Ni four-impeller hydrogenation protective agent; The hydrogenation refining agent is a W-Mo-Ni/gamma-Al 2 O 3 hydrogenation refining catalyst, wherein the active component in the W-Mo-Ni hydrogenation refining agent is 20-40% in terms of oxide, the hydrogenation refining agent is prepared by adopting a gamma-Al 2 O 3 as a carrier, the loading amount of NiO is 2-5%, the loading amount of MoO 3 is 7-27%, the loading amount of WO 3 is 5-12%, and the balance is a gamma-Al 2 O 3 carrier; The hydrocracking agent is a W-Ni/gamma-Al 2 O 3 /Y hydrocracking catalyst, wherein the active component in the W-Ni hydrocracking agent is 20-30% in terms of oxide content, ni and W are used as active components, gamma-Al 2 O 3 + molecular sieve Y is used as a carrier, the hydrocracking agent is prepared by an isovolumetric impregnation method, the NiO load is 5-7%, the WO 3 load is 15-23%, and the balance is gamma-Al 2 O 3 + molecular sieve Y carrier; The hydroisomerization catalyst is a W-Ni/gamma-Al 2 O 3 /SAPO-11 hydroisomerization catalyst, wherein the active component in the W-Ni hydroisomerization catalyst is 18-22% in terms of oxide content, ni and W are used as active components, gamma-Al 2 O 3 + molecular sieve SAPO-11 is used as a carrier, the hydroisomerization catalyst is prepared by an isovolumetric impregnation method, the NiO load is 3-6%, the WO 3 load is 13-18%, and the balance is gamma-Al 2 O 3 + molecular sieve SAPO-11 carrier.
2. The catalyst for preparing high-density special fuel from high-temperature coal tar according to claim 1, wherein the preparation method of the hydrofinishing agent is characterized in that tungsten trioxide precursor ammonium meta-tungstate, molybdenum trioxide precursor ammonium heptamolybdate and nickel monoxide precursor nickel nitrate Ni (NO 3 ) 2 ·6H 2 O are added into an ammonia water solution according to concentration ratio, the concentration of the ammonia water is 25-30%, the ammonia water is stirred at 15-60 ℃ to be completely dissolved, an active component solution is obtained, the active component solution is immersed into a carrier gamma-Al 2 O 3 for 3-5 hours, the active component solution is dried at 20-30 ℃ for 5-8 hours, the active component solution is dried at 100 ℃ for 6-8 hours, and then the active component solution is heated to 450-550 ℃ at a temperature rising rate of 2-6 ℃ per minute, and the active component solution is baked for 6-8 hours, so that the hydrofinishing agent is prepared.
3. The catalyst for preparing high-density special fuel from high-temperature coal tar according to claim 1, wherein the preparation method of the hydrocracking agent comprises the steps of adding tungsten trioxide precursor ammonium metatungstate and nickel nitrate Ni (NO 3 ) 2 ·6H 2 O) into distilled water according to concentration proportion, stirring at 15-60 ℃ to enable the nickel nitrate Ni to be completely dissolved to obtain an active component solution, immersing the active component solution into a carrier gamma-Al 2 O 3 /Y, wherein the mass ratio of gamma-Al 2 O 3 to the Y carrier is 8:2, immersing for 3-5 hours, drying at 20-30 ℃ for 5-8 hours, drying at 100 ℃ for 6-8 hours, heating at a heating rate of 2-6 ℃ per minute to 450-550 ℃, and roasting for 6-8 hours to obtain the hydrocracking agent.
4. The catalyst for preparing high-density special fuel from high-temperature coal tar according to claim 1, wherein the preparation method of the hydroisomerization agent comprises the steps of adding tungsten trioxide precursor ammonium metatungstate and nickel nitrate Ni (NO 3 ) 2 ·6H 2 O) into distilled water according to concentration proportion, stirring at 15-60 ℃ to enable the nickel nitrate Ni to be completely dissolved to obtain an active component solution, then impregnating the active component solution into a carrier gamma-Al 2 O 3 /SAPO-11, wherein the mass ratio of gamma-Al 2 O 3 to SAPO-11 is 8:2, impregnating for 3-5 hours, drying at 20-30 ℃ for 5-8 hours, drying at 100 ℃ for 6-8 hours, and then heating to 450-550 ℃ at a heating rate of 2-6 ℃ per minute, and roasting for 6-8 hours to obtain the hydroisomerization agent.
5. The catalyst for preparing high-density special fuel from high-temperature coal tar according to claim 1, wherein the bird nest-shaped hydrogenation protective agent has a size of phi (6-45) mm (6-15) mm, a void ratio of 60% -70%, a specific surface area of 800m 2 /g~2000m 2 /g, the Mo-Ni hydrogenation protective agent is a Mo-Ni/gamma-Al 2 O 3 protective agent, the active component in the Mo-Ni protective agent is in the form of oxide MoO 3 0.7.7-3.1%, the NiO content is 1.3-4%, the Mo-Ni hydrogenation protective agent is in the form of a four-leaf wheel, the size of phi (1.7-8.0) mm (3-10) mm, the pile ratio is 0.43g/cm 3 ~0.80g/cm 3 , the specific surface area is 100m 2 /g~150m 2 /g, and the pore volume is 0.3cm 3 /g~0.7cm 3 /g.
6. The catalyst for preparing high-density special fuel from high-temperature coal tar according to claim 1, wherein the Mo-Ni hydrogenation refining agent is clover-shaped, has the size phi (1.8-3.5) mm x (3-8) mm, the pile ratio of 0.65g/cm 3 ~0.90g/cm 3 , the specific surface area of 60m 2 /g~300m 2 /g and the pore volume of 0.3cm 3 /g~0.8cm 3 /g; The W-Ni hydrocracking agent is strip-shaped, the size of the W-Ni hydrocracking agent is phi (2.0-3.5) mm multiplied by (3-8) mm, the pile ratio is 0.65g/cm 3 ~0.90g/cm 3 , the specific surface area is 60m 2 /g~350m 2 /g, and the pore volume is 0.3cm 3 /g~0.8cm 3 /g; The W-Ni hydroisomerization agent is bar-shaped, the size is phi (2.0-3.5) mm multiplied by (3-8) mm, the pile ratio is 0.65g/cm 3 ~0.90g/cm 3 , the specific surface area is 60m 2 /g~350m 2 /g, and the pore volume is 0.3cm 3 /g~0.8cm 3 /g.
7. A grading method of a catalyst for preparing high-density special fuel from high-temperature coal tar according to any one of claims 1-6 is characterized in that catalysts are sequentially filled along the material flow direction in a reactor, wherein (1) bird nest-shaped hydrogenation protecting agent is filled in a filling ratio of 4-10%, (2) Mo-Ni/gamma-Al 2 O 3 protecting agent is filled in a filling ratio of 10-16%, the (3) W-Mo-Ni/gamma-Al 2 O 3 hydrofining catalyst is filled in a filling ratio of 25-50%, the (4) W-Ni/gamma-Al 2 O 3 /Y hydrocracking catalyst is filled in a filling ratio of 15-30%, the (5) W-Ni/gamma-Al 2 O 3 /SAPO-11 hydroisomerizing catalyst is filled in a filling ratio of 10-30%, inert ceramic balls are respectively filled at the top end and the low end of the catalyst, the filling ratio is 5-10% of the volume of the reactor, and the inert ceramic balls have high mechanical strength and can provide stable support for the catalyst.
8. Use of the catalyst according to any one of claims 1-6 in preparing high-density special fuel from high-temperature coal tar.
9. The method for preparing the high-density special fuel is characterized by comprising the steps of adopting a fixed bed reactor, removing sulfur, nitrogen, oxygen, metal impurities and olefin of high-temperature coal tar through catalyst grading of each bed layer in the reactor, carrying out aromatic saturation, cracking and isomerization, and finally purifying the coal tar to improve the quality of oil products, and preparing the high-density special fuel, wherein the high-temperature coal tar is a high-temperature coal tar distillate with the temperature of <360 ℃, namely, the high-temperature coal tar distillate for cutting off the asphalt component.
10. The method according to claim 9, wherein the catalyst is filled with nest-shaped hydrogenation protecting agent, mo-Ni hydrogenation protecting agent, W-Mo-Ni hydrogenation refining agent, W-Ni hydrocracking agent and W-Ni hydrogenation isomerising agent from top to bottom in a fixed bed reactor, inert porcelain balls are respectively filled at the top end and the low end of the catalyst, the catalyst is placed in a middle constant temperature zone of the reactor, a pipeline is sealed and leak-detected, then the catalyst is vulcanized, CS 2 kerosene solution is used as vulcanized liquid, the temperature is raised to 300-370 ℃ under the action of hydrogen pressure of 2.0-4.0 MPa, the volume airspeed is set to be 0.2- -1 ~0.5 h -1 h, the temperature is raised to 320-380 ℃ after the vulcanization is finished, coal tar raw materials are pumped into the reactor under the conditions of 4-8 MPa after the temperature is reduced to room temperature, the volume ratio of hydrogen is 1500-800, the air speed is -1 ~0.3 h -1 h, the hydrogenation reaction is carried out under the condition of the volume ratio of the liquid is -1 ~0.3 h -1 h, and the specific distillate density is obtained after the specific distillate is cut to be 190-300 ℃.

Description

Catalyst for preparing high-density special fuel from high-temperature coal tar, grading method and application thereof Technical Field The invention belongs to the technical field of high-density special fuel preparation, and particularly relates to a catalyst for preparing high-density special fuel from high-temperature coal tar, a grading method and application thereof. Background Coal tar is a main byproduct of coal pyrolysis, the main components of high-temperature coal tar are aromatic and heterocyclic compounds, most of the high-temperature coal tar is polycyclic and fused ring compounds with side chains or without side chains and heterocyclic compounds containing oxygen, sulfur and nitrogen, and the asphalt content of the high-temperature coal tar is usually more than 50%, so that the high-temperature coal tar is generally sticky, has a relative density greater than that of water and is black or blackish brown. In addition, high temperature coal tar contains more sulfur, nitrogen, oxygen and mechanical impurities, and polycondensation reaction is easy to occur, so that the hydrotreating difficulty of the high temperature coal tar is relatively high. The high-temperature coal tar hydrogenation product is polycyclic hydrocarbon, and the unique components enable the high-temperature coal tar hydrogenation product to have the characteristics of high density and volume heat value, so the high-temperature coal tar hydrogenation product is very suitable for processing and producing high-density fuel, but because the components have large difference, the high-temperature coal tar hydrogenation product should be modified before producing the high-density fuel, so the high-temperature coal tar hydrogenation product is more suitable for producing the high-density fuel. The high-density special fuel is usually jet fuel for special purposes, such as military aircrafts, high-altitude detectors, rockets and the like, and has the characteristics of high energy density, low combustion temperature, high heat efficiency, good combustion controllability and the like. The main components of the high-density special fuel are hydrocarbon compounds, such as naphthene and isomers thereof, and additives such as antiknock agents, antipyretics and the like. The chemical composition of the high-density special fuel has great influence on the generation of carbon deposit, and in an engine, aromatic hydrocarbon is easy to generate carbon deposit, especially the dicyclic aromatic hydrocarbon, so that the content of aromatic hydrocarbon substances such as the dicyclic aromatic hydrocarbon and the like in the high-density special fuel is required to be strictly limited. The coal tar hydrogenation process can be used for removing, cracking or isomerizing partial aromatic compounds to prepare clean gasoline and diesel oil, wherein the aromatic content is higher, the oil can be hydrogenated and saturated and isomerised to obtain high-density coal-based special oil by improving and optimizing the hydrogenation process and technology, and the catalyst is the core of the whole hydrogenation reaction, and the quality of the oil can be obviously improved by improving a hydrogenation catalyst system. Since the 50 s of the 20 th century, jet fuels in the united states have been mainly of the RJ-4, RJ-5, RJ-7, jp-5, jp-9, jp-10 series, all of which are synthetic hydrocarbon fuels and are costly to produce. Catalytic cracking diesel (LCO) and coal-based liquefied oil are mixed and hydrotreated in a volume ratio of 1:1 by the national institute of energy and use of state (Fuel Processing Technology, 89 (2008) 364-378) to obtain a main coal-based jet fuel JP-900. The density (20 ℃) range of the most widely used military and civil RP-3 jet fuel in China is 0.775-0.830 g/cm 3, the volume heat value is about 35.5 MJ/L, the density (20 ℃) of the high-energy jet fuel is more than 0.900 g/cm 3, and the volume heat value is higher than 38.3 MJ/L. Therefore, the research uses high-temperature coal tar as a raw material, converts aromatic hydrocarbon in the high-temperature coal tar into naphthene hydrocarbon through hydrotreatment to produce high-density jet fuel, is an effective way for high-value utilization of the high-temperature coal tar, and is also a preferred way for developing coal-based special fuel in China. Chinese patent CN105694970a discloses a method for producing high density jet fuel by hydrogenating low temperature coal tar, which comprises the steps of carrying out hydrogenation reaction on medium and low temperature coal tar by hydrogenation protection catalyst and hydrofining catalyst, carrying out clay refining on crude jet fuel to obtain high density No. 6 jet fuel, wherein the density is 910kg/m 3, the aromatic hydrocarbon content is 7%, the temperature is Wen Ningdian-48 ℃, and the yield is about 60%, but the multi-stage hydrogenation (protection+refining), fractionation and clay refining combined process has long flow, large equ