Method for reducing yield of catalytic solid phase product of poor heavy oil pyrolysis by using waste shells

Abstract

The application discloses a method for reducing the yield of solid phase products in catalytic pyrolysis of inferior heavy oil by using waste shells, which comprises the following steps: cleaning, drying and calcining the waste shells to obtain shell powder; mixing the shell powder with inferior heavy oil and then performing pyrolysis reaction to obtain non-solid phase products and solid phase products; and performing catalytic reaction on the non-solid phase products to separate gas phase and liquid phase products. The application uses renewable waste shell resources as an added component in the pyrolysis reaction zone of catalytic pyrolysis of inferior heavy oil, which is more conducive to environmental protection, conforms to the development trend of low-carbon and emission-reduction green chemical industry, and the shell powder is mixed with inferior heavy oil for pyrolysis and catalysis, the characteristics of the large porosity of the shell powder make the volatile components more quickly leave the pyrolysis reaction zone and rise to the catalytic reaction zone to be converted into light components, so that the content of solid phase products in the pyrolysis products is significantly reduced, and the yield of high-value light components is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of petrochemicals, and in particular to a method for reducing the yield of catalytic solid phase products in the pyrolysis of poor heavy oil using waste shells. BACKGROUND

[0002] The world's oil resources are becoming increasingly heavy and poor, and the proportion of heavy crude oil is becoming larger, which makes the proportion of poor heavy oil by-produced after primary and secondary processing of crude oil also increasing. At present, there are two processes for processing poor heavy oil, namely decarburization and hydrogenation. The former mainly includes coking and solvent deasphalting processes, etc.; the latter mainly has boiling bed and suspension bed two process types. Coking and hydrogenation are widely used heavy oil processing technologies. Coking process can process poor heavy oil with high sulfur, high metal and high carbon residue, but has problems such as low liquid product yield and poor comprehensive economy, making it difficult to realize efficient utilization of poor heavy oil. The boiling bed and slurry bed hydrogenation processes have problems such as large device investment and high device operation cost.

[0003] Ethylene tar is a by-product of ethylene cracking device in the petrochemical industry, with high asphaltene content, belonging to the category of poor heavy oil. At present, ethylene tar is mainly used as heavy fuel oil or carbon black raw material for sale.

[0004] Patent documents with publication numbers CN1970688B and CN106883871B and some enterprises disclose comprehensive utilization methods of ethylene tar, such as extracting naphthalene and its series products therefrom, using light components to synthesize petroleum resin, using heavy tar to produce carbon fiber pitch and carbon fiber, and using heavy fraction greater than 540℃ to produce activated carbon, etc., but the comprehensive utilization rate is only about 50%. The patent document with publication number CN109609182A uses delayed coking method to process ethylene tar, and the yield of high value-added products is about 80%, of which more than 10% is heavy wax oil, and the yield of light fuel with high added value is low.

[0005] Catalytic off-spec oil slurry is a by-product of catalytic cracking device in the petrochemical industry, which is mainly sold as cheap fuel oil or a small amount of blending into coking device, causing waste of oil resources. At present, the production of catalytic oil slurry in China is about 7.5 million tons / year. Under the current situation of decreasing profits in oil refining, developing a technical route with better comprehensive economy of catalytic oil slurry is an urgent problem to be solved for refineries.

[0006] Patent literature with publication number CN102703101B mixes ethylene tar with waste plastic or plastic oil in a certain mass ratio, uses GG12 catalyst for catalysis, and the obtained solid phase product is at least 8%, which is about 19% converted to ethylene tar. Patent literature with publication number CN103789037B mixes ethylene tar and heavy benzene, and after pyrolysis catalytic reaction, the solid phase product is about 12.0%, which is at least about 13% converted to ethylene tar itself. Patent literature with publication number CN104611060B mixes high aromatic components with waste plastic oil in a certain proportion, and after pyrolysis reaction by combining gradually increasing temperature with constant temperature operation, the solid phase product is at least 4.0%, which is about 8% converted to ethylene tar itself. The common feature of the above methods is that there is only reaction raw material in the pyrolysis reaction zone without adding any other substances, resulting in high solid phase product yield, i.e. low gas phase and liquid phase products with higher economic value.

[0007] Maximizing the utilization rate of renewable resources in nature is conducive to the low-carbon and green development of the country. At present, with the rapid development of shellfish culture and processing industry in China, a large amount of discarded shells are produced every year, which cannot be fully utilized, and are piled up year by year, causing serious environmental pollution and occupying a large amount of valuable land resources. At the same time, due to the decomposition of meat residues attached to the shells by microorganisms, gases such as NH3, H2S and amines are produced, causing secondary pollution to the environment and human beings. According to statistics, 0.3-0.7 kg of discarded shells will be produced for every 1 kg of shellfish processed. The China Fishery Statistical Yearbook shows that the total yield of marine shellfish in China in 2020 was 14.8 million tons. Thus, about 7.4 million tons of discarded shells will be produced every year, which is considerable.

[0008] At present, discarded shellfish is mainly used as feed, solidifying agent, building material and water treatment agent, etc. Patent literature with publication number CN106345448B discloses a basic catalyst for preparing biodiesel, which uses shell powder as a carrier for biodiesel catalyst. Patent literature with publication number CN110038564A discloses a core-shell structure catalyst for efficiently purifying combustion exhaust gas, which uses shell powder as a reinforcing agent for purifying combustion exhaust gas catalyst.

[0009] In the existing technology of pyrolysis catalysis of inferior heavy oil, there is a common problem of high yield of low-value solid phase product. In order to effectively improve the economy of inferior heavy oil, it is necessary to use more advanced processing methods to improve the yield of high-value light fuel, thereby increasing the value-added rate of inferior heavy oil per ton of raw material, so as to further reduce the cost and increase the economic benefit of refining enterprises. SUMMARY

[0010] In order to solve the above technical problems, the application provides a method for reducing the yield of solid phase products in the catalytic pyrolysis of poor heavy oil by using waste shells, which comprises the following steps: mixing the heavy oil with the pretreated shell powder, and then performing pyrolysis and catalytic reaction, so that the content of solid phase products in the pyrolysis products is significantly reduced, and the yield of high-value light components is improved.

[0011] A method for reducing the yield of solid phase products in the catalytic pyrolysis of poor heavy oil by using waste shells, which comprises the following steps:

[0012] (1) washing, drying and calcining the waste shells to obtain shell powder;

[0013] (2) mixing the shell powder with the poor heavy oil, and then performing pyrolysis to obtain non-solid phase products and solid phase products; performing catalytic reaction on the non-solid phase products to separate the gas phase and liquid phase products.

[0014] The application utilizes the large porosity of the shell powder, mixes the shell powder with the poor heavy oil, and uses the shell powder as an added component of the pyrolysis and catalytic raw material, so that the poor heavy oil is heated more uniformly during the reaction, the heat supply is more continuous and stable, the easily volatile components in the poor heavy oil rise to the catalytic reaction zone under the action of sufficient heat to become light components instead of being retained at the bottom of the reactor as low-value solid phase products due to incomplete reaction; more importantly, for the olefin compounds generated by pyrolysis, the addition of the shell powder enables the olefin compounds to quickly leave the pyrolysis reaction zone and rise to the catalytic reaction zone to be converted into light components, thereby effectively avoiding the opportunity of self-polymerization or mutual polymerization into high polymers due to being blocked in the pyrolysis reaction zone, so that the content of solid phase products in the pyrolysis products is significantly reduced, and the yield of high-value light components is significantly improved.

[0015] Preferably, in step (1), the waste shells refer to the outer shells of aquatic mollusks that are discarded after being eaten or processed, i.e., the hard outer shells of shellfish organisms.

[0016] The application uses waste shell resources as an added component of the pyrolysis reaction zone for the pyrolysis and catalysis of poor heavy oil, which not only effectively reduces the content of solid phase products, but also is more conducive to environmental protection and conforms to the development trend of low-carbon and emission-reduction green chemical industry.

[0017] Preferably, in step (1), the washing temperature is 20-30℃, the time is 1-5h, and the volume ratio of the waste shells to water is 1:1-1:3.

[0018] Preferably, in step (1), the drying temperature is 100-120℃, and the time is 1-5h.

[0019] Preferably, in step (1), the calcination temperature is 900-1000℃, and the time is 1-3h.

[0020] Preferably, in step (1), the particle size of the shell powder is 0.2-2 mm.

[0021] Preferably, in step (2), the inferior heavy oil includes ethylene tar or catalytic cracking slurry oil in petrochemical industry. The ethylene tar is a by-product of naphtha cracking for ethylene production, and the catalytic cracking slurry oil is heavy oil discarded by catalytic cracking production device. The present application uses inferior heavy oil as raw material, which can convert low-value inferior heavy oil into clean fuel product, and can significantly improve the economic benefit of the factory.

[0022] Preferably, in step (2), the mass ratio of the shell powder to the inferior heavy oil is 1:10-1:100.

[0023] Preferably, in step (2), the temperature of the pyrolysis reaction is 100-520℃, the pressure is normal pressure-0.80 MPa, and the time is 2-4 h.

[0024] Preferably, in step (2), the yield of the solid phase product is <5 wt%. The yield of the solid phase product prepared by the present application is <5 wt%, which is significantly lower than the yield of the solid phase product obtained by using the prior art.

[0025] Preferably, in step (2), the temperature of the catalytic reaction is 60-350℃, and the time is 2.5-5 h.

[0026] Preferably, in step (2), the catalyst for the catalytic reaction is one or more of HY, Ni-REY, HZSM-5, HC-1 molecular sieve catalyst, or modified catalyst SiO2 / Al2O3.

[0027] Preferably, the mass of the catalyst is 0.5-2.0% of the mass of the inferior heavy oil.

[0028] Preferably, in step (2), the pyrolysis reaction and the catalytic reaction occur in different two reaction zones in the same reactor, and the catalytic reaction zone is located at the upper part of the pyrolysis reaction zone. After the pyrolysis reaction, non-solid phase products and solid phase products are obtained, and the non-solid phase products rise to the catalytic reaction zone to generate gas phase products and liquid phase products by catalytic reaction.

[0029] In the pyrolysis reaction zone, as the reaction temperature increases, small molecules and components with low boiling points in the reactants escape from the pyrolysis reaction zone and rise to the catalytic reaction zone to react with the catalyst in the catalytic reaction zone, and then continue to rise to the separation system to obtain gas phase products and liquid phase products by gas-liquid separation. These two are collectively referred to as non-solid phase products, and the solid phase products remain in the pyrolysis reaction zone.

[0030] Preferably, in step (2), the yield of the gaseous product is 4-6 wt%, and the yield of the liquid product is 90-92 wt%.

[0031] The gaseous product prepared by the present application can be used as fuel gas, and the liquid product can be used as feedstock of a hydrofining device for producing clean gasoline and diesel products.

[0032] Compared with the prior art, the present application has at least the following beneficial effects:

[0033] (1) The present application utilizes the large porosity of shell powder, which is mixed with inferior heavy oil as an added component of catalytic pyrolysis raw material, so that the inferior heavy oil is heated more uniformly during the reaction, and the heat supply is more continuous and stable, so that the easily volatile components in the inferior heavy oil rise more to the catalytic reaction zone under the action of sufficient heat to become light components instead of being retained at the bottom of the reactor as low-value solid products due to incomplete reaction. More importantly, for the olefin compounds produced by pyrolysis, the addition of shell powder allows them to have more channels to quickly leave the pyrolysis reaction zone and rise to the catalytic reaction zone to be converted into light components, effectively avoiding the opportunity of self-polymerization or mutual polymerization into high polymers due to being blocked in the pyrolysis reaction zone, thereby significantly reducing the content of solid products in the pyrolysis products and increasing the yield of high-value light components.

[0034] (2) The present application uses renewable waste shell resources as an added component of the pyrolysis reaction zone for catalytic pyrolysis of inferior heavy oil, which not only effectively reduces the content of solid products, but also is more beneficial to environmental protection, in line with the development trend of low-carbon, emission reduction and green chemical industry, significantly improves the utilization rate of renewable resources, protects land resources and benefits both human beings and sustainable development. DETAILED DESCRIPTION

[0035] In view of the deficiencies in the prior art, the present inventors have obtained the technical solution of the present application through long-term research and a large number of practices. In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, and therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0036] In the embodiments of the present application, the waste shell used is waste oyster shell or mussel shell. The calcination equipment uses a high-temperature box-type electric furnace of ZCGWL model produced by Shandong Zhongchen Furnace Co., Ltd. with a silicon-molybdenum rod as the heating element. Unless otherwise specified, the raw materials, solvents and reagents used in the following embodiments of the present application are obtained by conventional commercial purchase.

[0037] Example 1

[0038] Take 100 g of discarded oyster shells, wash them at 20°C for 3 h with a volume ratio of clean water to 1:1, then dry them at 110°C for 5 h. After drying, the discarded oyster shells are calcined at 900°C for 3 h to obtain shell powder B1 with a particle size of about 1.8 mm.

[0039] Mix the shell powder B1 with ethylene tar and place it in the bottom of the pyrolysis catalytic reactor for pyrolysis reaction. The mass ratio of shell powder B1 to ethylene tar is 1:100. The properties of the ethylene tar used in this example are shown in Table 1. The pyrolysis reaction conditions, catalysts used in the catalytic zone, reaction conditions in the catalytic zone, product distribution and product properties are shown in Table 2.

[0040] Example 2

[0041] Take 100 g of discarded oyster shells, wash them at 20°C for 3 h with a volume ratio of clean water to 1:1, then dry them at 110°C for 5 h. After drying, the discarded oyster shells are calcined at 900°C for 3 h to obtain shell powder B1 with a particle size of about 1.8 mm.

[0042] Mix the shell powder B2 with ethylene tar and place it in the bottom of the pyrolysis catalytic reactor for pyrolysis reaction. The mass ratio of shell powder B2 to ethylene tar is 5.5:100. The properties of the ethylene tar used in this example are shown in Table 1. The pyrolysis reaction conditions, catalysts used in the catalytic zone, reaction conditions in the catalytic zone, product distribution and product properties are shown in Table 2.

[0043] Example 3

[0044] Take 100 g of discarded oyster shells, wash them at 20°C for 3 h with a volume ratio of clean water to 1:1, then dry them at 110°C for 5 h. After drying, the discarded oyster shells are calcined at 900°C for 3 h to obtain shell powder B1 with a particle size of about 1.8 mm.

[0045] Mix the shell powder B3 with catalytic oil slurry and place it in the bottom of the pyrolysis catalytic reactor for pyrolysis reaction. The mass ratio of shell powder B3 to catalytic oil slurry is 1:10. The properties of the ethylene tar used in this example are shown in Table 1. The pyrolysis reaction conditions, catalysts used in the catalytic zone and their addition amount, reaction conditions in the catalytic zone, product distribution and product properties are shown in Table 2.

[0046] Comparative Example 1

[0047] The pyrolysis reaction zone of this comparative example does not add shell powder, and the others are the same as Example 1.

[0048] Table 1 Properties of ethylene tar and catalytic oil slurry used in Examples 1-3 and Comparative Example 1

[0049] Crude name Ethylene tar FCC slurry oil Density (20°C), kg m -3 ]] 1001.2 998.2 [S, pg g -1 ]] 202 10890 [N, pg g -1 ]] 148 1954 Four components, wt% Saturates 3.8 36.1 Aromatics 41.0 33.6 Resins 29.8 24.1 Asphaltenes 25.4 6.2 Distillation, °C IBP-EBP 128-412(90v％) 153-405(90v％)

[0050] The content of C1-C6 alkanes in the gas phase product of Example 2 is about 80.1% by sampling analysis, and the rest is H2, CO2, O2, N2, CO and the like, which can be used as fuel gas; the ash content in the residue (containing shell powder) of Example 2 is 6.6%, which can be used as a building material, such as a concrete reinforcing agent.

[0051] As can be seen from Table 2, the yield of the solid phase product obtained by pyrolysis and catalysis using the method of Examples 1-3 is significantly lower than that of Comparative Example 1. The yield of light fuel oil in Examples 1-3 is 90.2-91.2 wt%, and the total yield of light fuel (gas phase product + solid phase product) is 95.2-95.8 wt%, which is significantly higher than the yield of light fuel oil and the total yield of light fuel in Comparative Example 1, which shows that the method in the examples significantly improves the product added value of poor heavy oil.

[0052] Table 2 Pyrolysis / catalysis process conditions and product distribution and properties of Examples 1-3 and Comparative Example 1

[0053]

[0054] ① Properties of the solid phase product containing shell powder

[0055] The above description is only a preferred embodiment of the present application, and does not limit the present application in any way. Any simple modification, change and equivalent transformation of the above embodiment according to the technical essence of the present application still falls within the protection scope of the technical solution of the present application.

Claims

1. A method for reducing the yield of catalytic solid phase products from the pyrolysis of poor quality heavy oil using waste shells, characterized by, The application relates to a method for preparing a solid-phase product from waste shells. The method comprises the following steps: (1) washing, drying and roasting the waste shells to obtain shell powder, wherein the roasting temperature is 900-1000 DEG C, and the roasting time is 1-3 hours; (2) mixing the shell powder with inferior heavy oil and then performing pyrolysis reaction to obtain a non-solid-phase product and a solid-phase product; performing catalytic reaction on the non-solid-phase product to separate gas-phase and liquid-phase products; 2. The method of claim 1, wherein, the pyrolysis reaction is performed at a temperature of 100-520 DEG C, a pressure of normal pressure-0.80 MPa and a time of 2-4 hours.

3. The method of claim 1, wherein, In step (1), the washing temperature is 20-30 DEG C, the washing time is 1-5 hours, and the volume ratio of the waste shells to water is 1:1-1:

3.

4. The method of claim 1, wherein, In step (1), the particle size of the shell powder is 0.2-2 mm.

5. The method of claim 1, wherein, In step (2), the inferior heavy oil includes ethylene tar and catalytic cracking external slurry, and the mass ratio of the shell powder to the inferior heavy oil is 1:10-1:

100.

6. The method of claim 1, wherein, In step (2), the catalytic reaction is performed at a temperature of 60-350 DEG C and a time of 2.5-5 hours.

7. The method of claim 6, wherein, In step (2), the catalyst for the catalytic reaction is one or more of HY, Ni-REY, HZSM-5 and HC-1 molecular sieve catalysts.

8. The method of claim 1, wherein, In step (2), the catalyst mass is 0.5-2.0% of the mass of the inferior heavy oil. In step (2), the pyrolysis reaction and the catalytic reaction occur in different reaction zones in the same reactor, and the catalytic reaction zone is located at the upper part of the pyrolysis reaction zone.

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