Production process for producing low-sulfur marine fuel oil through hydro-liquefaction of waste rubber tires

Abstract

The invention belongs to the technical field of solid waste resource utilization, and particularly relates to a production process for producing low-sulfur marine fuel oil through waste rubber tire hydro-liquefaction, which comprises the following steps: (1) mixing oil slurry, waste tire rubber powder and a catalyst to obtain a mixture, enabling the mixture to pass through a swelling preheater, and enabling the mixture and hydrogen to enter a slurry bed reactor for hydro-liquefaction, the liquefied intermediate product passes through a high-pressure separator, hydrogen obtained through separation enters a fixed bed hydrofining device, and obtained liquid enters a rectifying tower through a pressure reducing valve; (2) feeding a liquid product at the bottom of the rectifying tower and hydrogen into a fixed bed hydrofining device; and (3) carrying out gas-liquid separation on the fixed bed hydrofining product, wherein the liquid obtained by the gas-liquid separation is the low-sulfur marine fuel oil. According to the invention, waste tire rubber powder and slurry oil are used as raw materials, the liquefaction of waste rubber tires is realized in high-pressure hydrogen and high-temperature environments, and a fixed bed hydrofining device is combined to further reduce the content of sulfur atoms so as to produce the low-sulfur fuel oil for ships.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste resource utilization, and specifically relates to a production process for producing low-sulfur marine fuel oil by hydrogenating and liquefying waste rubber tires. Background Art

[0002] By the end of 2024, my country's automobile ownership will reach 440 million, and hundreds of millions of waste tires are generated every year due to automobile operation and scrapping. Since the main material of rubber tires is a high-molecular substance, it is difficult to degrade in the natural environment and has a long impact on the ecological environment. At present, the utilization methods of waste rubber tires include primary utilization, tire retreading, tire pyrolysis, and tire coke making. Primary utilization mainly applies waste tires to dock protection, amusement facility shock absorption, etc. Refurbished tires can only be used for low-grade vehicles, and the number of retreads is limited. The retreading process consumes a lot of energy and has high resource utilization. Waste tires can be pyrolyzed to obtain products with high economic value such as pyrolysis oil, pyrolysis gas, carbon black and steel wire. It is a new technology that can maximize the resource utilization of waste tires. The Chinese invention patent application publication number CN103695021A discloses a method for preparing pyrolysis oil by co-pyrolysis and liquefaction of biomass and waste tires, wherein the biomass raw material and the waste tire raw material are crushed and dried respectively, and the two raw materials are subjected to pyrolysis reaction respectively to obtain pyrolysis vapor, and the two pyrolysis vapors are mixed in a certain proportion and passed through a zeolite solid catalyst, and co-pyrolysis reaction is carried out under the action of the catalyst to generate co-pyrolysis vapor, and the co-pyrolysis vapor is subjected to primary condensation and secondary condensation to obtain pyrolysis oil. By adjusting the flow rate of the two pyrolysis vapors to control the mixing ratio of the two, the problem of insufficient co-pyrolysis and poor pyrolysis effect caused by different specific gravity and thermal weight loss intervals of biomass and waste tires is effectively solved, and the co-pyrolysis effect of biomass and waste tires is improved, so that the quality of the pyrolysis oil of the co-pyrolysis product is improved. The Chinese invention patent application publication number CN108203588A discloses a method for treating waste tires with low-temperature pyrolysis in a nitrogen atmosphere, which uses inferior residual oil as a solvent and nitrogen as a protective gas to pyrolyze and liquefy waste tires in a gas-liquid-solid three-phase system. Compared with tire pyrolysis alone, this method has a higher liquid yield and a lower gas yield.

[0003] However, the current technology for liquefying rubber tires to produce oil products faces technical difficulties such as the difficulty of industrial continuous production technology and the need to improve the utilization rate of raw material resources. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a production process for producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires, which uses waste tire rubber powder and oil slurry as raw materials, realizes the liquefaction of waste rubber tires under high-pressure hydrogen and high-temperature environment, and combines with a fixed-bed hydrorefining device to further reduce the content of heteroatoms, especially sulfur atoms, to produce low-sulfur marine fuel oil.

[0005] The production process of producing low-sulfur marine fuel oil by hydrogenation and liquefaction of waste rubber tires according to the present invention comprises the following steps:

[0006] (1) The mixture obtained by mixing the slurry oil, the waste tire rubber powder and the catalyst passes through a swelling preheater and enters a slurry bed reactor together with the hydrogen from the hydrogen supply pipe for hydrogenation and liquefaction to obtain a liquefied intermediate product. The liquefied intermediate product passes through a high-pressure separator, and the hydrogen obtained by the high-pressure separator enters a fixed-bed hydrorefining device. The liquid obtained by the high-pressure separator enters a distillation tower through a pressure reducing valve;

[0007] (2) The liquid product at the top of the distillation tower (fraction <300°C) can be sold to downstream refineries as light fuel oil. The solid tailings at the bottom of the distillation tower (fraction >560°C) are treated as hazardous waste. The liquid product at the bottom of the distillation tower (fraction 300-560°C) and the hydrogen obtained from the high-pressure separator enter the fixed-bed hydrotreating unit for deep hydrodeoxygenation, denitrification and desulfurization to obtain the fixed-bed hydrotreating product;

[0008] (3) The fixed bed hydrogenation refining product undergoes gas-liquid separation, and the gas obtained by gas-liquid separation passes through a circulating hydrogen compressor. The tail gas of the circulating hydrogen compressor is used as a combustible gas. The hydrogen coming out of the circulating hydrogen compressor enters a circulating hydrogen pipe, which is connected to a hydrogen supply pipe to realize the recycling of hydrogen. The liquid obtained by gas-liquid separation is low-sulfur marine fuel oil.

[0009] Preferably, there are two slurry bed reactors, denoted as slurry bed reactor A and slurry bed reactor B, and the slurry bed reactor A and the slurry bed reactor B are connected in series;

[0010] The specific steps of step (1) are:

[0011] The mixture obtained by mixing the oil slurry, waste tire rubber powder and the catalyst passes through the swelling preheater and enters the slurry bed reactor A together with the hydrogen coming out of the hydrogen supply pipe, and then enters the slurry bed reactor B. After two-stage hydrogenation liquefaction, a liquefied intermediate product is obtained. The liquefied intermediate product passes through a high-pressure separator, and the hydrogen obtained by the high-pressure separator enters the fixed-bed hydrorefining device. The liquid obtained by the high-pressure separator enters the distillation tower through a pressure reducing valve.

[0012] The swelling preheater utilizes the swelling effect of the oil slurry to destroy the three-dimensional network structure and cross-linked bodies in the rubber tire; the slurry bed reactor A pre-hydrogenates the oil slurry to convert it into a hydrogen supply solvent; and the slurry bed reactor B thermally cracks the rubber tire to convert it into a liquid phase.

[0013] Preferably, the volume ratio of the swelling preheater, the slurry bed reactor A, and the slurry bed reactor B is 2:2:1.

[0014] Preferably, the slurry oil is one of FCC slurry oil and DCC slurry oil or a mixture of the two in any proportion.

[0015] Preferably, the catalyst is one or more of iron sulfide, iron oxyhydroxide, molybdenum disulfide, nickel sulfide, oil-soluble molybdenum, oil-soluble iron, and oil-soluble nickel.

[0016] Preferably, the amount of catalyst added is 0.1%-2% of the total mass of the slurry oil and the waste tire rubber powder, the mass ratio of the waste tire rubber powder to the slurry oil is 1:(2-4); the mesh size of the waste tire rubber powder is 40-100 meshes.

[0017] Preferably, the swelling preheater temperature is 200-280°C, and the air velocity is 0.25-0.5h -1 .

[0018] Preferably, the reaction temperature of the slurry bed reactor A is 320-380°C, and the space velocity is 0.25-0.5h -1 , hydrogen pressure 12-20MPa, hydrogen-oil ratio (800-2000): 1; slurry bed reactor B reaction temperature 440-480℃, space velocity 0.5-1.0h -1 , hydrogen pressure 12-20MPa, hydrogen-oil ratio (800-2000):1.

[0019] Preferably, a Mo-Ni / Al2O3 catalyst is provided in the fixed bed hydrorefining device, and the fixed bed hydrorefining process parameters are: reaction temperature 300-380°C, hydrogen pressure 12-20MPa, hydrogen-oil ratio (800-2000): 1, space velocity 0.5-2.0h -1 .

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. Use oil slurry to swell the rubber tire powder in the swelling preheater to destroy the three-dimensional network structure in the waste tire rubber powder and reduce the difficulty of thermal cracking of the rubber powder. At the same time, due to the large thermal resistance of the waste tire rubber powder, the oil slurry and the rubber powder are fully in contact and heat transfer in the swelling preheater to prevent the temperature difference of the slurry in the reaction system from being too large;

[0022] 2. Pre-hydrogenating the mixture of slurry oil and waste tire rubber powder in the slurry bed reactor A to partially hydrogenate the polycyclic aromatic hydrocarbons in the slurry oil to produce hydrogenated aromatic hydrocarbons. The present invention controls the reaction temperature to improve the hydrogenation saturation effect of the slurry oil and obtain as high a content of hydrogenated aromatic hydrocarbons as possible;

[0023] 3. The slurry bed reactor B further increases the reaction temperature and increases the space velocity by adjusting the reactor volume, and realizes the liquefaction and lightening of the polymer long chain of waste tire rubber powder under the action of thermal cracking. At the same time, under the action of hydrogen transfer of hydrogenated aromatics and the action of hydrogen free radicals generated by the catalyst, the free radicals generated by the cracking of waste tire rubber powder are prevented from condensing with each other to form coke, and the free radicals generated by the cracking of waste tire rubber powder are prevented from secondary cracking to form excessive gas;

[0024] 4. Since the waste tire rubber powder contains some cross-linked structures such as SC, SCS and epoxy functional groups, the generated liquefied oil has a high content of sulfur atoms and oxygen atoms. Therefore, the online combined fixed bed hydrorefining unit further reduces the content of S and O atoms;

[0025] 5. The present invention uses waste rubber tires and oil slurry as raw materials, realizes the liquefaction of waste rubber tires under high-pressure hydrogen and high-temperature environment, and combines with a fixed-bed hydrorefining device to further reduce the heteroatoms, especially the sulfur atom content, to obtain low-sulfur marine fuel oil; the present invention can not only efficiently realize the resource utilization of waste tires, but also produce low-sulfur marine fuel oil with high economic value and environmental friendliness; the present invention has the technical advantages of short process route, green and environmentally friendly industrial chain, good product quality, stable device operation, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the production process of producing low-sulfur marine fuel oil by hydrogenation and liquefaction of waste rubber tires according to the present invention;

[0027] In the figure, 1. stirred tank; 2. swelling preheater; 3. hydrogen supply pipe; 4. slurry bed reactor A; 5. slurry bed reactor B; 6. high-pressure separator; 7. pressure reducing valve; 8. distillation tower; 9. fixed bed hydrotreating unit; 10. gas-liquid separator; 11. circulating hydrogen compressor; 12. circulating hydrogen pipe. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments.

[0029] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0030] The slurry oil used in the examples is FCC slurry oil from a catalytic cracking unit of a refinery in Shandong, and the waste tire rubber powder used is sourced from waste rubber tires of an environmental protection company in Ningbo, Zhejiang.

[0031] In the devices involved in the embodiments, the swelling preheater and the slurry bed reactor A are 4L pilot reactors, and the slurry bed reactor B is a 2L pilot reactor.

[0032] The size of waste tire rubber powder is 60 mesh, and the mass ratio of waste tire rubber powder to oil slurry is 1:3. Fixed bed hydrorefining process parameters: reaction temperature 340℃, hydrogen pressure 18MPa, hydrogen-oil ratio 1200:1, air velocity 1.0h -1 .

[0033] The indicators of the slurry oil and waste tire rubber powder in the examples are shown in Table 1 and Table 2.

[0034] Table 1 Oil slurry composition

[0035] project unit Numeric density <![CDATA[g / cm 3 ]]> 1.1039 Ash wt% 0.031 Carbon residue wt% 10.47 Saturation wt% 12.18 Aroma wt% 85.00 Gel wt% 2.31 Asphaltene wt% 0.51 C wt% 89.68 H wt% 9.30 N wt% 0.29 S wt% 0.41 O wt% 0.31

[0036] Table 2 Composition of waste tire rubber powder

[0037] project unit Numeric Moisture wt% 0.46 Distribution wt% 68.44 Ash wt% 6.18 Fixed Carbon wt% 24.92 C wt% 82.33 H wt% 7.42 N wt% 0.48 S wt% 2.00 O and others wt% 7.77

[0038] like Figure 1 As shown, the production process of producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires in Example 1-3 comprises the following steps:

[0039] (1) The mixture obtained by mixing the slurry oil, the waste tire rubber powder and the catalyst in the stirred tank 1 passes through the swelling preheater 2 and enters the slurry bed reactor A4 together with the hydrogen from the hydrogen supply pipe 3, and then enters the slurry bed reactor B5, and obtains a liquefied intermediate product after two-stage hydrogenation liquefaction. The liquefied intermediate product passes through the high-pressure separator 6, and the hydrogen obtained by the high-pressure separator enters the fixed bed hydrotreating device. The liquid obtained by the high-pressure separator passes through the pressure reducing valve 7 and enters the distillation tower 8;

[0040] (2) The liquid product at the top of the distillation tower (fraction < 300°C) is used as light fuel oil, and the solid tailings at the bottom of the distillation tower (fraction > 560°C) are treated as hazardous waste. The liquid product at the bottom of the distillation tower (fraction 300-560°C) and the hydrogen obtained from the high-pressure separator enter the fixed-bed hydrotreating device 9 (with a Mo-Ni / Al2O3 catalyst) for deep hydrodeoxygenation, denitrification and desulfurization to obtain a fixed-bed hydrotreating product;

[0041] (3) The fixed bed hydrogenation refining product is separated into gas and liquid by a gas-liquid separator 10, and the gas obtained by the gas-liquid separation passes through a circulating hydrogen compressor 11. The tail gas of the circulating hydrogen compressor 11 is used as a combustible gas. The hydrogen coming out of the circulating hydrogen compressor 11 enters a circulating hydrogen pipe 12, and the circulating hydrogen pipe 12 is connected to the hydrogen supply pipe 3 to realize the recycling of hydrogen; the liquid obtained by the gas-liquid separation is low-sulfur marine fuel oil.

[0042] Among them, the specific process parameters of each embodiment are as follows:

[0043] Example 1

[0044] The catalyst is molybdenum disulfide catalyst, and the total amount of the catalyst added accounts for 1% of the total mass of the slurry oil and the waste tire rubber powder.

[0045] The swelling preheater temperature is 260℃, the mixed slurry feed rate is 2L / h (space velocity is 0.5h -1 );

[0046] Slurry bed reactor A reaction conditions: mixed slurry feed rate 2L / h (space velocity 0.5h -1 ), reaction temperature 320°C, reaction pressure 18MPa, hydrogen-to-oil ratio 1200:1;

[0047] Slurry bed reactor B reaction conditions: mixed slurry feed rate 2L / h (space velocity 1h -1 ), reaction temperature 440°C, reaction pressure 18MPa, hydrogen-to-oil ratio 1200:1.

[0048] Example 2

[0049] The catalyst is an iron oxyhydroxide catalyst, and the total amount of the catalyst added accounts for 1% of the total mass of the slurry oil and the waste tire rubber powder.

[0050] The swelling preheater temperature is 260℃, the mixed slurry feed rate is 2L / h (space velocity is 0.5h -1 );

[0051] Slurry bed reactor A reaction conditions: mixed slurry feed rate 2L / h (space velocity 0.5h -1 ), reaction temperature 320°C, reaction pressure 18MPa, hydrogen-to-oil ratio 1200:1;

[0052] Slurry bed reactor B reaction conditions: mixed slurry feed rate 2L / h (space velocity 1h -1 ), reaction temperature 440°C, reaction pressure 18MPa, hydrogen-to-oil ratio 1200:1.

[0053] Example 3

[0054] The catalyst is an oil-soluble molybdenum catalyst, and the total amount of the catalyst added accounts for 1% of the total mass of the oil slurry and the waste tire rubber powder.

[0055] The swelling preheater temperature is 260℃, the mixed slurry feed rate is 2L / h (space velocity is 0.5h -1 );

[0056] Slurry bed reactor A reaction conditions: mixed slurry feed rate 2L / h (space velocity 0.5h -1 ), reaction temperature 360°C, reaction pressure 18MPa, hydrogen-to-oil ratio 1200:1;

[0057] Slurry bed reactor B reaction conditions: mixed slurry feed rate 2L / h (space velocity 1h -1), reaction temperature 465°C, reaction pressure 18MPa, hydrogen-to-oil ratio 1200:1.

[0058] The product yields of Examples 1-3 are shown in Table 3 below, and the component indicators of the obtained low-sulfur marine fuel oil are shown in Table 4 below.

[0059] Table 3 Product yields of Examples 1-3

[0060] Yield (%) Example 1 Example 2 Example 3 exhaust 3.65 8.46 4.74 <360℃ fraction 10.99 17.51 12.98 Low sulfur fuel oil 73.23 59.35 74.85 Tailings 12.13 14.68 7.43

[0061] Table 4 Component index of low sulfur marine fuel oil in Example 1-3

[0062] Experimental Results Example 1 Example 2 Example 3 <![CDATA[Viscosity (mm 2 / s)]]> 16 14 9 Flash point(℃) >60 >60 >60 Sulfur content (%) 0.010 0.014 0.008 Moisture (%) Trace Trace Trace Ash content (%) Trace Trace Trace

[0063] From the comparative results of the embodiments in Table 3 and Table 4, it can be seen that the present invention can effectively convert waste tires into liquid fuels, and the total yield of the fraction <360°C and the liquid fuel of fuel oil is more than 85%, and the yield of the target product of the produced fuel oil can reach more than 70%. At the same time, under the action of slurry bed hydrotreating and fixed bed hydrofining, the key technical indicators of the produced fuel oil such as viscosity, sulfur content, flash point, moisture, ash content, etc. meet the marine fuel oil use standard (GB17411-2015), especially the sulfur content is less than 0.1%, which is particularly suitable for use in low-sulfur fraction marine fuel base oil.

[0064] The present invention can not only realize the resource utilization of waste tires efficiently, but also produce low-sulfur marine fuel oil with high economic value and environmental friendliness. The technology has the technical advantages of short process route, green and environmentally friendly industrial chain, good product quality, stable device operation, etc.

Claims

1. A production process for producing low-sulfur marine fuel oil by hydrogenation and liquefaction of waste rubber tires, characterized in that: The steps include: (1) The mixture obtained by mixing the slurry oil, the waste tire rubber powder and the catalyst passes through a swelling preheater and enters a slurry bed reactor together with the hydrogen from the hydrogen supply pipe for hydrogenation and liquefaction to obtain a liquefied intermediate product. The liquefied intermediate product passes through a high-pressure separator, and the hydrogen obtained by the high-pressure separator enters a fixed-bed hydrorefining device. The liquid obtained by the high-pressure separator enters a distillation tower through a pressure reducing valve; (2) The liquid product at the top of the distillation tower is used as light fuel oil, and the solid tailings at the bottom of the distillation tower are treated as hazardous waste. The liquid product at the bottom of the distillation tower and the hydrogen obtained from the high-pressure separator enter the fixed-bed hydrotreating unit for deep hydrodeoxygenation, denitrification, and desulfurization to obtain a fixed-bed hydrotreating product; (3) The fixed bed hydrogenation refining product undergoes gas-liquid separation, and the gas obtained by gas-liquid separation passes through a circulating hydrogen compressor. The tail gas of the circulating hydrogen compressor is used as a combustible gas. The hydrogen coming out of the circulating hydrogen compressor enters a circulating hydrogen pipe, which is connected to a hydrogen supply pipe to realize the recycling of hydrogen. The liquid obtained by gas-liquid separation is low-sulfur marine fuel oil.

2. The production process for producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires according to claim 1, characterized in that: There are two slurry bed reactors, denoted as slurry bed reactor A and slurry bed reactor B, and the slurry bed reactor A and the slurry bed reactor B are connected in series; The specific steps of step (1) are as follows: the mixture obtained by mixing the oil slurry, the waste tire rubber powder and the catalyst passes through a swelling preheater and enters into a slurry bed reactor A together with the hydrogen from the hydrogen supply pipe, and then enters into a slurry bed reactor B. After two hydrogenation steps, a liquefied intermediate product is obtained, the liquefied intermediate product passes through a high-pressure separator, the hydrogen obtained by the high-pressure separator enters into a fixed-bed hydrotreating device, and the liquid obtained by the high-pressure separator enters into a distillation tower through a pressure reducing valve.

3. The production process for producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires according to claim 2, characterized in that: The volume ratio of the swelling preheater, the slurry bed reactor A, and the slurry bed reactor B is 2:2:

1.

4. The production process for producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires according to claim 1, characterized in that: The slurry oil is one of FCC slurry oil and DCC slurry oil or a mixture of the two in any proportion.

5. The production process for producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires according to claim 1, characterized in that: The catalyst is one or more of iron sulfide, iron oxyhydroxide, molybdenum disulfide, nickel sulfide, oil-soluble molybdenum, oil-soluble iron, and oil-soluble nickel.

6. The production process for producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires according to claim 1, characterized in that: The amount of catalyst added is 0.1%-2% of the total mass of the oil slurry and the waste tire rubber powder, the mass ratio of the waste tire rubber powder to the oil slurry is 1:(2-4); the mesh number of the waste tire rubber powder is 40-100 meshes.

7. The production process for producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires according to claim 1, characterized in that: Swelling preheater temperature 200-280℃, air velocity 0.25-0.5h -1 .

8. The production process for producing low-sulfur marine fuel oil by hydrogenation and liquefaction of waste rubber tires according to claim 2, characterized in that: Slurry bed reactor A reaction temperature 320-380℃, space velocity 0.25-0.5h -1 , hydrogen pressure 12-20MPa, hydrogen-oil ratio (800-2000): 1; slurry bed reactor B reaction temperature 440-480℃, space velocity 0.5-1.0h -1 , hydrogen pressure 12-20MPa, hydrogen-oil ratio (800-2000):

1.

9. The production process for producing low-sulfur marine fuel oil by hydrogenation liquefaction of waste rubber tires according to claim 1, characterized in that: The fixed bed hydrotreating unit is equipped with Mo-Ni / Al2O3 catalyst. The fixed bed hydrotreating process parameters are: reaction temperature 300-380℃, hydrogen pressure 12-20MPa, hydrogen-oil ratio (800-2000): 1, space velocity 0.5-2.0h -1 .

Images