A method for producing light hydrocarbons and light oil from biomass raw materials

Abstract

A method for producing light hydrocarbons and light oil from biomass feedstock. The hydrotreated biomass feedstock is sequentially passed through a first hydrocracking reaction zone, a second hydrocracking reaction zone, and a supplemental refining reaction zone for reaction. The resulting hydrocracking reaction effluent is separated to produce light hydrocarbons, light oil, and unconverted oil. At least a portion of the unconverted oil is recycled to the first hydrocracking reaction zone for further reaction. The method of the present invention can convert the biomass feedstock into biomass light hydrocarbon products and biomass light oil products.

Description

Technical Field

[0001] The present invention relates to the field of biomass raw material processing, and in particular to a method for producing light hydrocarbons and light oil from biomass raw materials. Background Art

[0002] Biomass renewable oils and fats are animal and plant oils or waste cooking oils and fats. They are a renewable resource with abundant sources and large usage. Existing technologies have disclosed relevant technologies for using renewable oils and fats to produce transportation fuels (such as jet fuel and diesel).

[0003] CN108441260A discloses a hydrogen countercurrent oil hydrogenation process, in which biorenewable oil is contacted with a hydrotreating catalyst in the presence of hydrogen to undergo a first-stage hydrotreating to obtain refined oil. The refined oil is then contacted with an isomerization catalyst in the presence of hydrogen to undergo a second-stage hydroisomerization pour point decompression treatment, and then separated by distillation to obtain biomass fuel. Fresh hydrogen is introduced into the second hydrodecompression stage, and the hydrogen-rich gas after the reaction is circulated to the first-stage hydrotreating. The hydrogen-rich gas obtained after the first-stage hydrotreating is subjected to impurity removal treatment and then enters the second-stage hydrotreating together with the fresh hydrogen. An amine washing device is used for gas purification.

[0004] CN106318433A and CN106256880A disclose a method for hydrogenating animal and vegetable oils and fats. In a hydrogenation reactor, hydrogen and a control gas, vegetable oil or animal and vegetable oils and fats are contacted with a sulfided hydrogenation catalyst and reacted under hydrogenation reaction conditions to obtain a hydrogenation reaction product. The control gas is CO or CO2, the partial pressure of hydrogen in the reaction zone is 1.0 to 20.0 MPa, and the ratio of the hydrogen partial pressure to the control gas partial pressure is 2 to 300. The hydrogenation reaction product is subjected to gas-liquid separation to obtain a liquid hydrocarbon stream / gas stream and water. The liquid stream is C8-C 24 Normal alkanes. By controlling the partial pressure of the gas, the reaction is directed toward deoxygenation, reducing the decarbonization of the raw material and increasing the deoxygenation reaction, thereby reducing the CO and CO2 content of the reaction products and retaining carbon atoms in the liquid hydrocarbon products.

[0005] CN106281729A discloses a method for hydrotreating renewable raw materials. In the presence of hydrogen and water, vegetable oil or animal or vegetable fat is contacted with a sulfurized hydrotreating catalyst and reacted under hydrotreating reaction conditions to obtain a hydrotreating reaction product. The mass of water entering the hydrotreating reactor accounts for 1% to 20% of the mass of the vegetable oil or animal or vegetable fat, preferably 3% to 14%. One or more of hydrogen sulfide, CS2, dimethyl disulfide, methyl sulfide, n-butyl sulfide, and thiophene are mixed into the animal or vegetable fat before entering the hydrotreating reactor.

[0006] CN106190286A discloses a method for preparing jet fuel. Hydrogen and animal and vegetable oils are first subjected to a hydrodeoxygenation reaction to produce normal alkanes. The hydrodeoxygenation reaction product and hydrogen are then subjected to an isomerization-depression reaction in an isomerization-depression reaction zone provided with zones A and B, so that the mass fraction of isoalkanes in the product reaches 50% or more while the normal alkanes and isoalkanes are 100%. The isomerization reaction product is refined in a hydrorefining reaction zone, and the reaction effluent is separated and fractionated to obtain jet fuel.

[0007] CN102206502A discloses a method for co-refining animal and plant oils and oxygen-containing compounds to produce aromatic hydrocarbons and light olefins. The animal and plant oils and oxygen-containing compounds are introduced into a catalytic cracking reactor for reaction. The reaction products are separated to obtain liquefied gas, gasoline and other fractions. The liquefied gas is subjected to gas separation to obtain light olefins, and the gasoline is subjected to aromatic extraction to obtain aromatic products.

[0008] As can be seen from the above-listed prior art, existing biomass feedstock processing technologies, particularly hydrogenation technologies, primarily focus on using biomass feedstock to produce products such as low-aromatic solvent oil (65°C-174°C), jet fuel, and diesel. Therefore, it is imperative to develop hydrogenation methods that can directly produce light hydrocarbons or light oil from biomass feedstock, thereby achieving green and clean light hydrocarbon and light oil production in my country and reducing the carbon footprint of feedstock. Summary of the Invention

[0009] The present invention aims to solve the technical problem of how to effectively utilize biomass raw materials to produce light hydrocarbons and light oil products.

[0010] The method provided by the present invention for producing light hydrocarbons and light oil from biomass raw materials comprises: the biomass raw material after hydrogenation treatment is mixed with hydrogen and then enters a first hydrocracking reaction zone to contact with an optional hydrogenation protective agent and a reduced hydrocracking catalyst I for reaction; the reaction effluent directly enters a second hydrocracking reaction zone to contact with a reduced hydrocracking catalyst II for reaction; the acidic component of the hydrocracking catalyst I is amorphous silica-alumina, and the acidic component of the hydrocracking catalyst II is a medium-pore molecular sieve; the reaction effluent from the second hydrocracking reaction zone enters a supplementary refining reaction zone after heat exchange, and contacts with a non-precious metal hydrorefining catalyst for supplementary refining reaction;

[0011] The hydrogenation reaction effluent obtained in the supplementary refining reaction zone is separated to obtain light hydrocarbons, light oil and unconverted oil. At least a portion of the unconverted oil is recycled to the first hydrocracking reaction zone to continue the reaction. The light hydrocarbons are hydrocarbons less than C4, the light oil is hydrocarbons in the range of C5 and above to a final distillation point of 90°C, and the initial distillation point of the unconverted oil is 65°C to 90°C.

[0012] In the present invention, the biomass raw materials include one or more of various animal and plant oils and fats, and waste cooking oils.

[0013] The plant and animal oils include vegetable oils and animal fats, as well as raw materials containing glycerides and free fatty acids, and fatty acid methyl esters or fatty acid ethyl esters prepared from vegetable oils and / or animal fats through an ester exchange process. The glycerides include triglycerides, diglycerides, and monoglycerides. The plant oils include, but are not limited to, one or more of soybean oil, rapeseed oil, cottonseed oil, corn oil, rice bran oil, sunflower oil, peanut oil, castor oil, sesame oil, prickly ash seed oil, tea oil, coconut oil, olive oil, Pistacia chinensis oil, palm oil, tung oil, jatropha oil, rosin oil, and Chinese tallow tree oil.

[0014] Waste cooking oil refers to waste oil that is no longer suitable for consumption and is generated during the processing and consumption of animal and plant oils. This includes fatty acids and acidified oils produced during the production of edible oils from oilseeds; frying oil, kitchen waste oil, slop oil, and other types of waste cooking oil generated by households, hotels, restaurants, and food production companies; animal fat produced as a byproduct of meat production and processing; and edible oil that has exceeded its shelf life.

[0015] Because the biomass feedstock contains certain impurities such as sulfides, nitrides, and oxides, it requires hydrotreatment to remove these impurities before entering the first hydrocracking reaction zone of the present invention. However, the present invention is not limited to the specific hydrotreatment process; any hydrotreatment process that can reduce the impurity content of the biomass feedstock to a certain level is suitable for the present invention.

[0016] In a preferred embodiment of the present invention, the sulfur content, nitrogen content and oxygen content in the biomass feedstock after hydrogenation are all less than 20 μg / g.

[0017] In order to improve the yield of light hydrocarbons and light oil, the present invention adopts two hydrocracking catalysts with different acidic components for grading. In one embodiment of the present invention, the catalyst loading volume ratio of the first hydrocracking reaction zone to the second hydrocracking reaction zone is 3:1 to 1:3.

[0018] To further improve the quality of light hydrocarbons and light oil, the present invention provides a supplemental refining reaction zone downstream of the second hydrocracking reaction zone, employing a non-precious metal hydrorefining catalyst for supplemental refining. In one embodiment of the present invention, the catalyst loading volume ratio of the second hydrocracking reaction zone to the supplemental refining reaction zone is 2:1 to 15:1.

[0019] In one embodiment of the present invention, based on the overall catalyst in the first hydrocracking reaction zone, the volume fractions of the hydrogenation protectant and the hydrocracking catalyst I are: 0% to 20%; 80% to 100%, respectively.

[0020] In one embodiment of the present invention, the hydrogenation protective agent comprises a carrier and an active metal component supported on the carrier, the carrier is selected from one or more of aluminum oxide, silicon oxide and titanium oxide, the active metal component is selected from one or more of Group VIB metals and Group VIII non-precious metals, and the active metal component is 0.1 to 15% by weight, calculated as oxide, based on the weight of the hydrogenation protective agent. The particle size of the hydrogenation protective agent is 0.5 to 50.0 mm, and the bulk density is 0.3 to 1.2 g / cm 3 , with a specific surface area of 50 to 300 m 2 / g.

[0021] In one embodiment of the present invention, the hydrocracking catalyst I contains a support and a hydrogenation-active metal component. The support contains alumina or silica-alumina. Based on the support, the content of alumina is 20 to 80% by weight, and the content of silica-alumina is 80 to 20% by weight. The hydrogenation-active metal component is selected from any one or more of Mo, Co, Ni, W, V, Zn, Pt and Pd, and preferably contains Pt and / or Pd. Based on the total weight of the hydrocracking catalyst I as 100%, the content of the hydrogenation-active metal component, calculated as oxide, is 0.1 to 20% by weight.

[0022] In one embodiment of the present invention, the hydrocracking catalyst II contains a support and a hydrogenation-active metal component, the support contains a mesoporous molecular sieve and alumina, the hydrogenation-active metal component is selected from any one or more of Mo, Co, Ni, W, V, Zn, Pt and Pd, preferably contains Pt and / or Pd, based on the total weight of the hydrocracking catalyst II, the content of the mesoporous molecular sieve is 20 to 80 weight%, the content of alumina is 15 to 75 weight%, and the content of the hydrogenation-active metal component is 0.1 to 10 weight% calculated as oxide; the mesoporous molecular sieve is selected from one or more of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-38, SAPO-11 and SAPO-41.

[0023] In one embodiment of the present invention, the non-precious metal hydrorefining catalyst is a supported catalyst, the carrier is alumina and / or silica-alumina, the hydrogenation active metal component is at least one metal selected from Group VIB and at least one metal selected from Group VIII, the Group VIII metal is selected from nickel and / or cobalt, and the Group VIB metal is selected from molybdenum and / or tungsten. Based on the total weight of the non-precious metal hydrorefining catalyst, the content of the Group VIII metal is 1 to 15% by weight, and the content of the Group VIB metal is 5 to 40% by weight, calculated as oxide.

[0024] In the present invention, the hydrocracking catalyst I and the hydrocracking catalyst II need to be reduced before use. The present invention does not limit the reduction process, and the technical solutions of single reduction or double reduction are applicable to the present invention.

[0025] In one embodiment of the present invention, hydrocracking catalyst I and hydrocracking catalyst II are reduced in the presence of hydrogen to obtain the reduced hydrocracking catalyst I and reduced hydrocracking catalyst II, with a reduction temperature of 300 to 420° C., a reduction time of 8 to 32 hours, and a reduction operating pressure of 0.3 to 3.0 MPa.

[0026] In one embodiment of the present invention, the reaction conditions of the first hydrocracking reaction zone and the second hydrocracking reaction zone are: hydrogen partial pressure of 1.0 MPa to 20.0 MPa, reaction temperature of 350°C to 420°C, preferably 355 to 400°C, liquid hourly volume space velocity of 0.5 h -1 ~6h -1 , the hydrogen-to-oil volume ratio is 300-2000.

[0027] In one embodiment of the present invention, the reaction conditions of the supplementary refining reaction zone are: hydrogen partial pressure of 1.0 MPa to 20.0 MPa, reaction temperature of 230°C to 340°C, liquid hourly volume space velocity of 0.5 h -1 ~15h -1 , the hydrogen-to-oil volume ratio is 300-2000.

[0028] The present invention recycles a portion of the unconverted oil to the first hydrocracking reaction zone for continued reaction, primarily to maximize the conversion of normal paraffins in the light oil, increase the light oil octane number, and simultaneously produce a higher yield of light hydrocarbon products. Furthermore, due to the deep cracking of the feedstock and the high exothermicity of the cracking reaction, recirculating a certain proportion of the unconverted oil helps remove the bed reaction heat and facilitates temperature control of the cracking bed. Therefore, in a preferred embodiment of the present invention, the recycle ratio of the unconverted oil is controlled to be 15% to 30%, where the unconverted oil recycle ratio is the ratio of the weight of the unconverted oil to the weight of the fresh feedstock.

[0029] In the present invention, the obtained light hydrocarbons are C1-C4 gases, which can be separated into dry gas and liquefied gas products, or further separated into methane, ethane, propane, butane and other gas products.

[0030] In one embodiment of the present invention, light oil is separated by an n-isoparaffin adsorption separation unit to obtain a hydrocarbon component rich in isoparaffins and a hydrocarbon component rich in n-paraffins, wherein the hydrocarbon component rich in n-paraffins is used as a raw material or solvent oil product for a steam cracking ethylene production unit, and the hydrocarbon component rich in isoparaffins can be used as a high-octane gasoline blending component.

[0031] In a preferred embodiment of the present invention, the hydrogen is produced by utilizing one or more of wind power, hydropower, or solar energy.

[0032] Features of the present invention:

[0033] (1) When treating low-sulfur and low-nitrogen biomass feedstock that has been hydrotreated, the prior art uses a sulfurized hydrocracking catalyst for hydrocracking. During operation, in order to maintain the stability of the sulfurized catalyst activity, it is necessary to add a sulfurizing agent during operation. The present invention uses a reduced hydrocracking catalyst, which eliminates the need for sulfur addition.

[0034] (2) The present invention utilizes amorphous silica-alumina hydrocracking catalyst I in the first hydrocracking reaction zone to achieve feedstock lightweighting. In the second hydrocracking reaction zone, a medium-pore size-selective molecular sieve hydrocracking catalyst II is utilized to further convert the normal paraffin products in the first hydrocracking unit, producing light hydrocarbons while retaining isoparaffins as a high-octane light oil product. Furthermore, the two hydrocracking catalysts with different acidic centers employed in the present invention are graded, resulting in suitable cracking activity, high biomass feedstock conversion rate, and good operational stability.

[0035] (3) On the one hand, normal alkanes are low-octane components in light oil products. The present invention is beneficial to converting normal alkanes in light oil by controlling a certain unconverted oil circulation ratio, while retaining the isoparaffin components in light oil, thereby achieving the goal of enriching isoparaffins in light oil and improving the octane number of light oil; on the other hand, by converting normal alkanes in light oil as much as possible, a higher light hydrocarbon yield can also be obtained; in addition, since the degree of cracking of the raw materials of the present invention is deep, the cracking reaction releases a large amount of heat, and the bed temperature rises, by controlling a certain tail oil circulation ratio, it is beneficial to take away more reaction heat, which is beneficial to controlling the temperature rise of the cracking bed. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of one embodiment of the method for producing light hydrocarbons and light oil from biomass raw materials provided by the present invention. DETAILED DESCRIPTION

[0037] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited thereto.

[0038] Figure 1 FIG. 1 is a schematic diagram of one embodiment of the method for producing light hydrocarbons and light oil from biomass raw materials provided by the present invention. Figure 1As shown, the hydrotreated biomass feedstock 1 and hydrogen 2 enter the first hydrocracking reaction zone 3 together, where they come into contact with a hydrogenation protective agent and hydrocracking catalyst I for reaction. The reaction effluent enters the second hydrocracking reaction zone 4, where it continues to react with hydrocracking catalyst II. The reaction effluent then enters the supplementary refining reaction zone 5, where it comes into contact with a non-precious metal hydrorefining catalyst for supplementary refining reaction. The hydrogenation reaction effluent obtained from the supplementary refining reaction zone is cooled by heat exchange with the outlet stream of the circulating hydrogen compressor and then enters a cold high-pressure separator 6 for gas-liquid separation. The high-fraction gas 7 separated from the top of the cold high-pressure separator is recovered as hydrogen, mixed with supplementary hydrogen 8, and then enters the circulating hydrogen compressor for recycling. The liquid phase stream obtained from the cold high-pressure separator enters a cold low-pressure separator 9 for further gas-liquid separation. The gaseous material obtained at the top of the cold low-pressure separator 9 and the liquid material obtained at the bottom of the cold low-pressure separator 9 enter the fractionation tower 10 through different inlets for separation. The unconverted oil 11 obtained at the bottom of the fractionation tower is recycled for reaction. Light oil is drawn off the side of the fractionation tower 10 and sent to the alkane normal isomerization separation unit 12 for separation, producing a hydrocarbon fraction rich in normal paraffins 13 and a hydrocarbon fraction rich in isoparaffins 14. The overhead stream of the fractionation tower 10 is cooled and then enters the deethanizer 15 for separation. Dry gas 16 is separated at the top of the tower, and propane and butane 17 is separated at the bottom of the deethanizer 15 as a liquefied gas product for delivery.

[0039] The present invention will be further described below with reference to the examples, but the present invention is not limited thereto.

[0040] In the examples and comparative examples, the component analysis data of the liquefied gas (propane and butane) samples were obtained according to SH / T0230 “Determination of the composition of liquefied petroleum gas (chromatographic method)”.

[0041] Table 1 lists the main properties of biomass raw oil after hydrotreatment.

[0042] Table 2 lists the physical and chemical properties of the catalysts used in the examples and comparative examples of the present invention. The catalysts with commercial brands are all produced by Sinopec Catalyst Branch.

[0043] The preparation method and composition of the hydrocracking catalyst II (CAT-2) used in the second hydrocracking reaction zone of the present invention are as follows:

[0044] A ZSM-22 molecular sieve (supplied by Changling Catalyst Factory, with a silicon-aluminum ratio of 56) was uniformly mixed with pseudo-boehmite and sesbania powder. A nitric acid aqueous solution was added and thoroughly kneaded. The mixture was then extruded into clover-shaped strips with a diameter of 1.3 mm on an extruder. The strips were dried at 120°C for 4 hours and then calcined at 600°C in air for 2 hours to obtain a support. The support was then saturated with a solution containing Pt(NH3)4Cl2, dried at 110°C for 4 hours, and calcined at 400°C in air for 3 hours to obtain a hydroisomerization catalyst. The catalyst contained 50.2% ZSM-22 by weight, 49.0% alumina by weight, and 0.8% Pt by weight.

[0045] Before use, hydrocracking catalyst I and hydrocracking catalyst II were reduced in a hydrogen atmosphere at a reduction temperature of 350° C., a reduction time of 4 hours, and a hydrogen pressure of 0.1 MPa.

[0046] Tables 3 and 4 list the data of the embodiments and comparative examples of the present invention, and Table 5 lists the product standard of liquefied petroleum gas GB 11174-2011 "Liquefied Petroleum Gas".

[0047] Example 1

[0048] The biomass feedstock 1 after hydrogenation treatment is mixed with hydrogen and enters the first hydrocracking reaction zone to contact with the hydrogenation protective agent and the reduced hydrocracking catalyst I for reaction. The reaction effluent directly enters the second hydrocracking reaction zone to contact with the reduced hydrocracking catalyst II for reaction. The reaction effluent of the second hydrocracking reaction zone enters the supplementary refining reaction zone after heat exchange and contacts with the non-precious metal hydrorefining catalyst for supplementary refining reaction.

[0049] The hydrogenation effluent from the supplementary refining reaction zone enters a high-pressure separator and a low-pressure separator sequentially for gas-liquid separation. The gaseous and liquid materials from the low-pressure separator enter a fractionation tower through different inlets for separation. The unconverted oil obtained at the bottom of the fractionation tower is recycled to the first hydrocracking reaction zone for further reaction. The recycle ratio of the unconverted oil is controlled at 23.58%, which is the ratio of the weight of the unconverted oil to the weight of the fresh feedstock.

[0050] Light oil extracted from the fractionator sideline is fed to the alkane normal isomerization unit for separation, yielding a hydrocarbon fraction rich in normal paraffins and a hydrocarbon fraction rich in isoparaffins. The overhead stream from the fractionator is cooled and then fed to the deethanizer for separation. Dry gas is separated from the top of the deethanizer, while liquefied gas is separated from the bottom of the deethanizer. Specific catalyst loading ratios, reaction conditions, and product yields are shown in Table 3.

[0051] Example 2

[0052] This example uses the same raw materials, process flow, and catalyst loading scheme as Example 1, except that the unconverted oil recycle ratio is controlled at 18.63%. Specific catalyst loading ratios, reaction conditions, and product yields are shown in Table 3.

[0053] As can be seen from Table 3, the methane yields of the products of Examples 1 and 2 were 5.51% and 13.86%, respectively, the ethane yields were 14.44% and 28.44%, the propane yields were 19.92% and 37.91%, respectively, the butane yields were 7.97% and 7.65%, respectively, and the C5-90°C light oil yields were 52.15% and 12.14%, respectively. The volume fractions of the hydrocarbon components in the deethanizer bottom liquefied gas (C3+C4) were 97.6% and 98.2%, respectively, all of which met the quality index requirements for commercial propane and butane liquefaction in GB 11174-2011 "Liquefied Petroleum Gas". After the product C5-90℃ light oil is separated by normal isomerization, the hydrocarbon component yields of C5-90℃ normal alkanes are 18.36% and 4.15% respectively, which can be used as high-quality raw materials for steam cracking ethylene production units; the hydrocarbon component yields of C5-90℃ isoalkanes are 33.79% and 7.99%, and their research octane numbers (RON) are 78 and 80 respectively, which can be used as low-aromatic and low-olefin gasoline blending components.

[0054] Comparative Example 1

[0055] This comparative example used the same raw materials and process as Example 1. Unlike Example 1, this comparative example also loaded hydrocracking catalyst II (CAT-2) into the first hydrocracking reaction zone. Specific catalyst loading ratios, reaction conditions, and product yields are shown in Table 3.

[0056] As can be seen from Table 3, in the comparative examples, hydrocracking catalysts I and II both used catalyst CAT-2 containing a medium-pore molecular sieve. The conversion rate of isoparaffins in the catalyst was not high. Even at a reaction temperature of 390°C, the conversion rate of the biomass feedstock was not high, resulting in a large unconverted oil circulation ratio of 63.7%. In addition, due to insufficient cracking conversion of isoparaffins, the light hydrocarbon yield was still low at a higher reaction temperature, and the methane yield was high, resulting in poor product selectivity.

[0057] Examples 3, 4 and 5

[0058] The biomass feedstock 2 after hydrogenation treatment is mixed with hydrogen and enters the first hydrocracking reaction zone to contact with the hydrogenation protective agent and the reduced hydrocracking catalyst I for reaction. The reaction effluent directly enters the second hydrocracking reaction zone to contact with the reduced hydrocracking catalyst II for reaction. The reaction effluent of the second hydrocracking reaction zone enters the supplementary refining reaction zone after heat exchange and contacts with the non-precious metal hydrorefining catalyst for supplementary refining reaction.

[0059] The hydrogenation reaction effluent obtained in the supplementary refining reaction zone enters the high-pressure separator and the low-pressure separator in sequence for gas-liquid separation. The gaseous and liquid phase materials obtained in the low-pressure separator enter the fractionating tower through different inlets for separation. The unconverted oil obtained at the bottom of the fractionating tower is recycled to the first hydrocracking reaction zone for further reaction. In Examples 3, 4, and 5, the recycle ratio of the unconverted oil is controlled to be 25.45%, 19.41%, and 18.58%, respectively. Light oil is extracted from the side line of the fractionating tower and sent to the alkane normal isomerization separation unit for separation to obtain a hydrocarbon component rich in normal paraffins and a hydrocarbon component rich in isoparaffins. The overhead stream of the fractionating tower is cooled and then enters the deethanizer for separation. Dry gas is separated from the top of the tower, and liquefied gas is separated from the bottom of the deethanizer. The specific catalyst loading ratio, reaction conditions, and product yields are shown in Table 4.

[0060] As can be seen from Table 4, the methane yields of the products of Examples 3, 4, and 5 are 10.46%, 13.28%, and 6.82%, the ethane yields are 24.19%, 27.95%, and 25.33%, and the propane yields are 55.70%, 54.51%, and 62.72%, respectively; the volume fractions of the hydrocarbon components of the liquefied gas (propane) at the bottom of the deethanizer are 95.21%, 98.75%, and 99.39%, respectively, all of which meet the quality index requirements of commercial propane in GB11174-2011 "Liquefied Petroleum Gas". After normal-isomer separation, the hydrocarbon component yields of the C5-90°C light oil are 2.54%, 1.46% and 1.68% respectively, which can be used as high-quality raw materials for steam cracking ethylene production units; the hydrocarbon component yields of the C5-90°C isoparaffins are 4.84%, 2.77% and 3.45%, and the research octane numbers (RON) are 78, 82 and 85 respectively, which can be used as low-aromatic and low-olefin gasoline blending components.

[0061] Table 1

[0062]

[0063]

[0064] Table 2

[0065] project Protective agent Hydrocracking agent 1 Sperm supplements Brand RG-30A / B RLF-10 RJW-3 Metal Ni / Mo Pt / Pd Ni / Mo / W Ni, wt% 0.5～1.5 / ≮3 Mo, wt% 2～6 / ≮1 W, wt% / / ≮26 Pt, wt% / ≮0.15 / Pd, wt% / ≮0.30 / Acidic component type / Amorphous silicon aluminum /

[0066] Table 3

[0067]

[0068]

[0069] Table 4

[0070]

[0071]

[0072] Table 5 GB 11174-2011 Specification requirements for liquefied petroleum gas

[0073]

[0074]

Claims

1. A method for producing light hydrocarbons and light oil from biomass feedstocks, comprising: the biomass feedstock after hydrogenation treatment is mixed with hydrogen and then enters a first hydrocracking reaction zone, where it contacts and reacts with an optional hydrogenation protective agent and a reduced hydrocracking catalyst I; the reaction effluent directly enters a second hydrocracking reaction zone, where it contacts and reacts with a reduced hydrocracking catalyst II; the acidic component of the hydrocracking catalyst I is amorphous silica-alumina, and the acidic component of the hydrocracking catalyst II is a medium-pore molecular sieve; the reaction effluent from the second hydrocracking reaction zone enters a supplementary refining reaction zone after heat exchange, where it contacts and reacts with a non-precious metal hydrorefining catalyst for a supplementary refining reaction; the catalyst loading volume ratio of the first hydrocracking reaction zone to the second hydrocracking reaction zone is 3:1 to 1:3, and the catalyst loading volume ratio of the second hydrocracking reaction zone to the supplementary refining reaction zone is 2:1 to 15:1; The hydrogenation reaction effluent obtained in the supplementary refining reaction zone is separated to obtain light hydrocarbons, light oil and unconverted oil, and at least a portion of the unconverted oil is recycled to the first hydrocracking reaction zone to continue the reaction. The light hydrocarbons are hydrocarbons less than C4, the light oil is hydrocarbons with a final boiling point ranging from C5 to 90°C, and the initial boiling point of the unconverted oil is 65°C to 90°C. Biomass raw materials include one or more of various animal and vegetable oils and catering waste oils.

2. The method according to claim 1, characterized in that The sulfur content, nitrogen content and oxygen content in the biomass raw material after hydrogenation are all less than 20 μg / g.

3. The method according to claim 1, characterized in that Based on the entire catalyst in the first hydrocracking reaction zone, the volume fractions of the hydrogenation protective agent and the hydrocracking catalyst I are: 0%~20%; 80%~100%, respectively.

4. The method according to claim 1, wherein The hydrogenation protective agent comprises a carrier and an active metal component supported on the carrier, wherein the carrier is selected from one or more of aluminum oxide, silicon oxide and titanium oxide, and the active metal component is selected from one or more of Group VIB metals and Group VIII non-precious metals. Based on the weight of the hydrogenation protective agent, the active metal component is 0.1 to 15% by weight in terms of oxide. The particle size of the hydrogenation protective agent is 0.5 to 50.0 mm, and the bulk density is 0.3 to 1.2 g / cm 3 , with a specific surface area of 50~300m 2 / g.

5. The method according to claim 1, wherein The hydrocracking catalyst I contains a carrier and a hydrogenation active metal component. The carrier contains alumina and silica-alumina. Based on the carrier, the content of alumina is 20-80% by weight, and the content of silica-alumina is 80-20% by weight. The hydrogenation active metal component is selected from any one or more of Mo, Co, Ni, W, V, Zn, Pt and Pd. Based on the total weight of the hydrocracking catalyst I being 100%, the content of the hydrogenation active metal component is 0.1-20% by weight, calculated as oxides.

6. The method according to claim 5, wherein the hydrogenation active metal component of the hydrocracking catalyst I is Pt and / or Pd.

7. The method according to claim 1, characterized in that The hydrocracking catalyst II contains a carrier and a hydrogenation-active metal component, wherein the carrier contains a mesoporous molecular sieve and alumina, and the hydrogenation-active metal component is selected from any one or more of Mo, Co, Ni, W, V, Zn, Pt and Pd. Based on the total weight of the hydrocracking catalyst II, the content of the mesoporous molecular sieve is 20-80% by weight, the content of the alumina is 15-75% by weight, and the content of the hydrogenation-active metal component, calculated as oxide, is 0.1-10% by weight. The mesoporous molecular sieve is selected from one or more of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-38, SAPO-11 and SAPO-41.

8. The method according to claim 7, wherein the hydrogenation active metal component of the hydrocracking catalyst II is Pt and / or Pd.

9. The method according to claim 1, characterized in that The non-precious metal hydrorefining catalyst is a supported catalyst, the carrier is alumina or silica-alumina, the hydrogenation active metal component is at least one metal selected from Group VIB and at least one metal selected from Group VIII, the Group VIII metal is selected from nickel and / or cobalt, and the Group VIB metal is selected from molybdenum and / or tungsten. Based on the total weight of the non-precious metal hydrorefining catalyst, the content of the Group VIII metal is 1-15% by weight, and the content of the Group VIB metal is 5-40% by weight, calculated as oxide.

10. The method according to claim 1, characterized in that The reaction conditions of the first hydrocracking reaction zone and the second hydrocracking reaction zone are: hydrogen partial pressure of 1.0 MPa~20.0 MPa, reaction temperature of 350℃~420℃, liquid hourly volume space velocity of 0.5h -1 ~6h -1 , the hydrogen-to-oil volume ratio is 300~2000.

11. The method according to claim 10, characterized in that The reaction temperature of the first hydrocracking reaction zone and the second hydrocracking reaction zone is 355~400℃.

12. The method according to claim 1, characterized in that The reaction conditions of the supplementary refining reaction zone are: hydrogen partial pressure of 1.0MPa~20.0MPa, reaction temperature of 230℃~340℃, liquid hourly volume space velocity of 0.5h -1 ~15h -1 , the hydrogen-to-oil volume ratio is 300~2000.

13. The method according to claim 1, wherein The circulation ratio of the unconverted oil is controlled to be 15% to 30%. The circulation ratio of the unconverted oil refers to the ratio of the weight of the recycled unconverted oil to the weight of the fresh raw material based on the weight of the fresh raw material.

14. The method according to claim 1, wherein The hydrogen is prepared by utilizing one or more of wind power, hydropower, or solar energy.

15. The method according to claim 1, wherein Light oil is separated by the normal-isopane adsorption separation unit to obtain hydrocarbon components rich in isoparaffins and hydrocarbon components rich in normal paraffins. The hydrocarbon components rich in normal paraffins are used as raw materials or solvent oil products for steam cracking ethylene production units, and the hydrocarbon components rich in isoparaffins are used as high-octane gasoline blending components.

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