Method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge
By incorporating a CaO catalyst layer into an integrated pyrolysis catalytic reactor, combined with high-temperature pyrolysis and long residence time, the problems of low hydrogen content and high carbon dioxide emissions in the pyrolysis of oily sludge have been solved, achieving efficient preparation and resource utilization of hydrogen-rich gas.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XI'AN PETROLEUM UNIVERSITY
- Filing Date
- 2026-03-09
- Publication Date
- 2026-05-12
AI Technical Summary
Existing pyrolysis technologies for oily sludge suffer from low pyrolysis temperatures and a lack of effective catalytic control, resulting in unreasonable product distribution, low hydrogen content, and high carbon dioxide emissions. Furthermore, traditional catalytic methods suffer from condensation losses and insufficient contact.
An integrated pyrolysis catalytic reactor with a built-in CaO catalyst layer is used. By combining high-temperature pyrolysis and long residence time, in-situ contact between pyrolysis gas and catalyst is achieved. Through the tar cracking and reforming reaction of CaO catalyst, hydrogen and methane generation are promoted in a targeted manner, while carbon dioxide production is suppressed.
It improved the yield and selectivity of hydrogen-rich gas, reduced carbon dioxide emissions, simplified the process, reduced costs, and achieved efficient resource utilization of oily sludge.
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Figure CN122010050A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of resource utilization of oily sludge and preparation of hydrogen-rich gas, and in particular to a method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge. Background Technology
[0002] Oily sludge is a large-scale industrial waste generated by industries such as petrochemicals, oil refining, and steel. Its complex composition mainly includes oil, water, solid particles, and harmful substances such as heavy metals and polycyclic aromatic hydrocarbons. Improper disposal can severely pollute soil, water bodies, and the atmosphere, threatening ecological security and human health. Its harmless treatment and resource utilization are urgent problems that the industry needs to solve. Traditional oily sludge treatment technologies, such as landfill, incineration, and biodegradation, have drawbacks such as resource waste, secondary pollution, or long treatment cycles, making it difficult to meet the needs of green development.
[0003] Resource utilization of oily sludge can, on the one hand, generate added economic value through resource treatment, and on the other hand, avoid secondary environmental pollution from the sludge. Hydrogen-rich gases (mainly hydrogen and methane), as clean and efficient energy carriers, have wide applications in industrial fuels, chemical synthesis, and hydrogen energy applications. Converting oily sludge into hydrogen energy can maximize the low-carbon economy and recycling of oily sludge.
[0004] In existing technologies, oily sludge pyrolysis gasification is mostly a single pyrolysis process. The pyrolysis temperature is relatively low and lacks effective catalytic control, resulting in an unreasonable product distribution. In conventional pyrolysis products, pyrolysis gas accounts for only 15%, pyrolysis oil 17%, and pyrolysis char 68%. Among gaseous products, hydrogen accounts for only 15%, while carbon dioxide accounts for as high as 19%. Furthermore, the pyrolysis gas has a short residence time and incomplete conversion, with heavy hydrocarbon components such as C2-C3 accounting for 24%. This not only reduces energy efficiency but also increases environmental pressure. In addition, some technologies attempt to introduce catalysis, but these are mostly external catalytic devices, which suffer from problems such as condensation loss during pyrolysis gas transmission and insufficient contact with the catalyst, failing to achieve efficient in-situ conversion.
[0005] Therefore, developing a directional pyrolysis technology for oily sludge based on in-situ catalysis and long residence time regulation to improve the yield and selectivity of hydrogen-rich gas and reduce carbon dioxide emissions is of great practical significance and application value. Summary of the Invention
[0006] The purpose of this invention is to provide a method for the directional catalytic pyrolysis of oily sludge to prepare hydrogen-rich gas, thereby increasing the pyrolysis gas yield and hydrogen content while reducing carbon dioxide emissions, and achieving efficient directional conversion of oily sludge into hydrogen-rich gas.
[0007] To achieve the above objectives, the present invention provides a method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge, comprising the following steps: S1. Pretreatment of oily sludge: The oily sludge is dried and crushed to control the moisture content of the pretreated oily sludge to be ≤30%, the particle size to be ≤5mm, and the coefficient of variation of mixing uniformity to be ≤10%. S2. Pyrolysis of oily sludge: The pretreated oily sludge is fed into an integrated pyrolysis catalytic reactor, an inert atmosphere is introduced, the temperature is raised to 650~700℃, and the pyrolysis reaction is carried out at this temperature to generate pyrolysis gas, pyrolysis oil and pyrolysis char. S3. In-situ catalysis and long residence time directional conversion: The integrated pyrolysis catalytic reactor has a built-in CaO catalyst layer, and the residence time of the pyrolysis gas is controlled to 1.5h. At a temperature of 650~700℃, the pyrolysis gas and CaO catalyst are in full contact in situ, and a catalytic conversion reaction occurs. S4. Hydrogen-rich gas collection: Collect the converted hydrogen-rich gas through the hydrogen-rich gas collection unit; S5. Product separation and catalyst regeneration: Hydrogen-rich gas is separated and purified by membrane separation or PSA pressure swing adsorption to obtain hydrogen and methane, respectively.
[0008] Preferably, in step S2, the inert atmosphere is nitrogen or argon with a purity ≥ 99.9%, and the flow rate is 5~20 m³ / s. 3 / h. Eliminating air interference allows the organic components in the oily sludge to fully decompose, generating pyrolysis gases containing hydrogen, methane, carbon dioxide, carbon monoxide, C2-C3 hydrocarbons, and tar vapor, while simultaneously producing pyrolysis oil and pyrolysis char.
[0009] Preferably, in S3, the CaO catalyst layer has a catalyst particle size of 1~10mm and a specific surface area of 30~200m². 2 / g, the mass ratio of CaO catalyst loading to oily sludge is 0.5~2:1, and the CaO catalyst layer adopts a honeycomb structure.
[0010] CaO catalysts catalyze pyrolysis gases to undergo reactions such as tar cracking, carbon oxide reforming, and light hydrocarbon conversion, directionally promoting the generation of hydrogen and methane, inhibiting the generation of carbon dioxide, and reducing the proportion of C2-C3 hydrocarbons.
[0011] Preferably, in S2, the heating rate is 5~10℃ / min.
[0012] Preferably, in S2, the pyrolysis gas includes hydrogen, methane, carbon dioxide, carbon monoxide, C2-C3 hydrocarbons, and tar vapor.
[0013] Preferably, in S4, the hydrogen-rich gas comprises the following volume percentage components: Hydrogen 30-31%, methane 41-43%, carbon dioxide 4-4.5%, carbon monoxide 17-19%, C2-C3 hydrocarbons 4-6%; The hydrogen-rich gas accounts for 24% of the total mass fraction of the pyrolysis products.
[0014] Preferably, after S5, the process further includes the regeneration of the CaO catalyst, specifically: Using air as the regeneration medium, the regeneration temperature is 600~800℃, the regeneration time is 2~4h, and the catalytic activity recovery rate after regeneration is ≥90%.
[0015] Preferably, in S2, the integrated pyrolysis catalytic reactor is provided with a regenerative radiant tube, a spiral guide plate, a buffer chamber, and a second-layer circulation unit. The regenerative radiant tube is used for precise temperature control, the spiral guide plate is used to guide the directional flow of pyrolysis gas, the buffer chamber is used to balance the airflow, and the second-layer circulation unit is used for the regeneration and cyclic catalysis of CaO catalyst.
[0016] Therefore, the present invention employs the above-mentioned method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge, and the beneficial effects are as follows: This invention employs high-temperature pyrolysis above 650℃, combined with in-situ CaO catalysis and a long residence time of 1.5h, to fully decompose the organic components of oily sludge. The total yield of pyrolysis gas is increased from 15% in conventional pyrolysis to 24%, while the yield of pyrolysis carbon is reduced from 68% to 60%, thus improving resource conversion efficiency and realizing the efficient resource utilization of oily sludge.
[0017] This invention utilizes the synergistic effect of CaO catalyst catalysis and adsorption to directionally promote hydrogen generation and inhibit carbon dioxide enrichment. The hydrogen content is increased from 15% in conventional pyrolysis to 31%, becoming the main component in hydrogen-rich gas. The carbon dioxide content is reduced from 19% to 4%, resulting in significant emission reduction. At the same time, the methane content is increased from 30% to 42%, and the C2-C3 hydrocarbon content is reduced from 24% to 5%, greatly optimizing the quality of hydrogen-rich gas and reducing the difficulty of subsequent separation and purification.
[0018] This invention employs an integrated pyrolysis catalytic reactor, embedding the CaO catalyst layer within the pyrolysis reaction zone to achieve in-situ contact between the pyrolysis gas and the catalyst. This eliminates the need for additional transport pipelines, avoiding condensation losses, heat loss, and component depletion of the pyrolysis gas during transport, ensuring full conversion of the pyrolysis gas, simplifying the process, and reducing costs.
[0019] This invention selects CaO as a catalyst, which is widely available, inexpensive, recyclable, and has a high activity recovery rate after regeneration, further reducing process operating costs and meeting the needs of large-scale industrial applications.
[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the integrated pyrolysis catalytic reactor, representing an embodiment of the method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to the present invention. Figure 2 This is a comparative diagram of pyrolysis gases from an embodiment of the method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to the present invention.
[0022] Figure Labels 1. Regenerative radiant tube; 2. Gas flow pipe; 3. Guide pipe; 4. Spiral guide plate; 5. Agitator; 6. Feed inlet; 7. Buffer chamber; 8. CaO catalyst layer; 9. Second-layer circulation unit; 10. Hydrogen-rich gas collection unit. Detailed Implementation
[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.
[0024] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0025] All embodiments of this invention employ an integrated pyrolysis catalytic reactor, such as... Figure 1 As shown, the reactor includes a regenerative radiant tube 1 and a gas flow pipe 2. The regenerative radiant tube 1 can be a unidirectional regenerative gas radiant tube, meaning that the heat generated by the combustion gas is supplied through the tube body via radiation. A gas regulating valve (not shown) can be installed on the regenerative radiant tube 1. Therefore, precise temperature control of the pyrolysis process can be achieved by adjusting the gas flow rate of the gas entering the regenerative radiant tube 1 through the gas regulating valve. The gas flow pipe 2 divides the interior of the reactor into a pyrolysis zone (high pressure zone), a catalytic zone (medium pressure zone), and a collection zone (low pressure zone). Pressure gradient control is achieved through a back pressure regulating valve (not shown), and the pressure difference provides continuous power for gas flow. Based on the effective volume of the reactor (the total volume of the guide + buffer chamber 7 + catalyst layer pores, denoted as V), combined with the generation rate of pyrolysis gas (denoted as Q1), the total gas flow rate Qtotal = V / τ (τ is the residence time 1.5h = 5400s) is used to calculate the inert gas replenishment flow rate (denoted as Q2), Q2 = Qtotal - Q1, ensuring that the gas flows unidirectionally and uniformly from the pyrolysis zone to the catalytic zone and then to the collection zone, without backflow or stagnation.
[0026] After pretreatment, the oily sludge enters the reactor pyrolysis zone through the feed inlet 6. The regenerative radiant tube 1 heats the sludge to 650~700℃. At the same time, the stirrer 5 fully stirs and pyrolyzes the oily sludge to generate pyrolysis gas. The high pressure in the pyrolysis zone drives the pyrolysis gas into the directional spiral guide plate 4. The spiral guide plate 4 guides the gas to flow in a directional direction. The pyrolysis gas enters the buffer chamber 7 and enters the CaO catalyst layer 8 evenly through the guide pipe 3. It penetrates the honeycomb channel in a directional manner, contacts the catalyst in situ, and undergoes a catalytic reaction. The gas after the reaction is driven by the pressure gradient to be directionally discharged to the hydrogen-rich gas collection unit 10.
[0027] In addition, the CaO catalyst layer 8 adopts an in-situ deactivation, offline regeneration, and backfill reuse process. CaO, as an adsorbent, reacts with CO2 in the pyrolysis gas in the CaO catalyst layer 8 to generate CaCO3, which covers the CaO surface and blocks the active sites. The deactivated CaO / CaCO3 mixed catalyst is then transferred to the second circulation unit 9 and calcined in an air atmosphere at 600~800℃ to restore the catalyst activity and achieve recycling. The second circulation unit 9 is connected to the CaO catalyst layer 8 through a quick-opening flange sealing door. The second circulation unit 9 is equipped with a heat storage radiant tube 1 and an air flow tube 2 to achieve catalyst activity restoration.
[0028] Example 1 A method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge includes the following steps: S1. Pretreatment of oily sludge: Oily sludge from a certain oil refinery was selected, dried by a drying device, and the moisture content was controlled to 28%. It was then crushed by a crushing device to a particle size ≤3mm, mixed evenly, and the coefficient of variation of the mixing uniformity was tested to be 8%.
[0029] S2. Pyrolysis of Oily Sludge: The pretreated oily sludge is fed into an integrated pyrolysis catalytic reactor at a rate of 100 kg / h. Nitrogen gas with a purity of 99.95% is introduced into the reactor as an inert atmosphere at a flow rate controlled at 10 m³ / h. 3 / h; The temperature inside the reactor is raised to 675℃ at a heating rate of 8℃ / min, and the temperature is maintained at this temperature to carry out the pyrolysis reaction, generating pyrolysis gas, pyrolysis oil and pyrolysis char.
[0030] S3. In-situ catalysis and long-stay directional conversion: Within the pyrolysis reaction zone of the integrated pyrolysis catalytic reactor, a CaO catalyst layer 8 is embedded. The CaO catalyst has a particle size of 3-5 mm and a specific surface area of 100 m². 2 / g, the mass ratio of catalyst loading to oily sludge is 1:1; the pyrolysis gas is guided to flow directionally through the CaO catalyst layer 8 by the built-in guide plate of the reactor, and the residence time of the pyrolysis gas in the CaO catalyst layer 8 and the reaction area is strictly controlled to 1.5h by nitrogen flow rate regulation. At a temperature of 675℃, the pyrolysis gas and CaO catalyst are fully contacted in situ, and a catalytic conversion reaction occurs.
[0031] S4. Hydrogen-rich gas collection: The converted hydrogen-rich gas is collected through the hydrogen-rich gas collection unit 10 at the top of the reactor. The composition of the hydrogen-rich gas is as follows, as detected by gas chromatograph: hydrogen 31%, methane 42%, carbon dioxide 4%, carbon monoxide 18%, and C2-C3 hydrocarbons 5%; at the same time, the distribution of pyrolysis products is detected, and the pyrolysis gas yield is 24%, the pyrolysis oil yield is 16%, and the pyrolysis char yield is 60%.
[0032] S5. Product Separation and Catalyst Regeneration: The collected hydrogen-rich gas was separated and purified using PSA (Pressure Swing Adsorption) to obtain hydrogen product with a purity of 96%, and the hydrogen yield was 7.44 m³. 3 / h; collect pyrolysis oil for use as fuel in industrial boilers; pyrolysis char is used to prepare activated carbon for resource utilization; deactivated CaO catalyst is regenerated by heating at 700℃ for 3h with air as the regeneration medium, and the activity recovery rate of the catalyst after regeneration is 92%, and it is returned to the catalyst bed for recycling.
[0033] In this embodiment, the oily sludge treatment rate is 100 kg / h, and the hydrogen-rich gas production rate is 24 m³ / h. 3 The process operates stably at / h, with no issues such as pipe blockage or secondary pollution.
[0034] Example 2 A method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge includes the following steps: S1. Pretreatment of oily sludge: Oily sludge from a petrochemical plant was selected, dried and controlled to have a moisture content of 25%, crushed to a particle size of ≤5mm, and mixed evenly. The coefficient of variation of the mixing uniformity was 9%.
[0035] S2. Pyrolysis of oily sludge: The pretreated oily sludge is fed into an integrated pyrolysis catalytic reactor at a rate of 200 kg / h. Argon gas with a purity of 99.9% is introduced as an inert atmosphere at a flow rate of 15 m³ / h. 3 / h; The temperature inside the reactor is raised to 685℃ at a heating rate of 10℃ / min, and the temperature is maintained to carry out the pyrolysis reaction, generating pyrolysis gas, pyrolysis oil and pyrolysis char.
[0036] S3. In-situ catalysis and long-stay directional conversion: An internal CaO catalyst layer 8 is used, with CaO catalyst particle size of 5-8 mm and a specific surface area of 150 m². 2 / g, the mass ratio of catalyst loading to oily sludge is 1.5:1; by equalizing the airflow through buffer chamber 7 and guiding the flow direction through guide plate, combined with argon flow rate regulation, the residence time of pyrolysis gas is controlled to 1.5h. At a temperature of 685℃, the pyrolysis gas and CaO catalyst are fully in situ in contact, and a catalytic conversion reaction occurs.
[0037] S4. Hydrogen-rich gas collection: The converted hydrogen-rich gas is collected through the hydrogen-rich gas collection unit 10 at the top of the reactor. The composition of the hydrogen-rich gas is as follows, as detected by gas chromatograph: hydrogen 31%, methane 42%, carbon dioxide 4%, carbon monoxide 18%, C2-C3 hydrocarbons 5%, and the pyrolysis products are distributed as pyrolysis gas 24%, pyrolysis oil 16%, and pyrolysis char 60%.
[0038] S5. Product Separation and Catalyst Regeneration: Hydrogen-rich gas is separated and purified using membrane separation to obtain hydrogen products with a purity of 95% and high-purity methane products, respectively; pyrolysis oil is used as a chemical raw material for further processing, and metal elements are recovered from pyrolysis carbon with a recovery rate of 82%; the deactivated CaO catalyst is regenerated using air as the regeneration medium and heated at 700℃ for 2.5 hours to complete the regeneration, with an activity recovery rate of 93%, and is returned to the catalyst bed for recycling.
[0039] In this embodiment, the oily sludge treatment rate is 200 kg / h, and the hydrogen-rich gas production rate is 48 m³ / h. 3 The process operates stably at a rate of / h, making it suitable for large-scale industrial production. It achieves significant hydrogen yield and carbon dioxide emission reduction, while also realizing the efficient resource utilization of pyrolysis oil and pyrolysis char, thus combining economic, environmental, and resource benefits.
[0040] Example 3 A method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge includes the following steps: S1. Pretreatment of oily sludge: Oily sludge from a petrochemical plant was selected, dried and controlled to have a moisture content of 25%, crushed to a particle size of ≤5mm, and mixed evenly. The coefficient of variation of the mixing uniformity was 9%.
[0041] S2. Pyrolysis of oily sludge: The pretreated oily sludge is fed into an integrated pyrolysis catalytic reactor at a rate of 200 kg / h. Argon gas with a purity of 99.9% is introduced as an inert atmosphere at a flow rate of 15 m³ / h. 3 / h; The temperature inside the reactor is raised to 685℃ at a heating rate of 10℃ / min, and the temperature is maintained to carry out the pyrolysis reaction, generating pyrolysis gas, pyrolysis oil and pyrolysis char.
[0042] S3, In-situ catalysis and long residence: Built-in fresh CaO catalyst layer 8 (particle size 5~8mm, specific surface area 150m²) 2 / g, loading ratio 1.5:1), guide plate + buffer chamber 7 control residence time 1.5h, complete the first catalysis; S4. Hydrogen-rich gas collection: The converted hydrogen-rich gas is collected through the hydrogen-rich gas collection unit 10 at the top of the reactor. The composition of the hydrogen-rich gas is as follows, as detected by gas chromatograph: hydrogen 31%, methane 42%, carbon dioxide 4%, and the product distribution meets the standards. S5. Catalyst Regeneration: The CaO catalyst that has completed the first catalysis is sent to the second circulation unit 9 and regenerated in air at 700℃ for 2.5h. The second circulation unit 9 completes the second catalysis. The "catalysis-regeneration" process is repeated to complete 5 cycles. After each cycle, the activity recovery rate of the CaO catalyst is tested and found to be ≥90%. After each cycle, the gas composition and product distribution are tested and found to maintain ≥30% hydrogen and ≤4.5% carbon dioxide.
[0043] Comparative Example 1 A method for preparing hydrogen-rich gas by catalytic decomposition of oily sludge includes the following steps: S1. Pretreatment of oily sludge: Oily sludge from a certain oil refinery was selected, dried by a drying device, and the moisture content was controlled to 28%. It was then crushed by a crushing device to a particle size ≤3mm, mixed evenly, and the coefficient of variation of the mixing uniformity was tested to be 8%.
[0044] S2. Pyrolysis of oily sludge: The pretreated oily sludge is fed into a conventional pyrolysis reactor with a flow rate of 10 m³ / h. 3 Using 99.95% pure nitrogen as an inert atmosphere, the temperature is increased to 700℃ at a rate of 8℃ / min and maintained for pyrolysis; no CaO catalyst layer is set, and the residence time of the pyrolysis gas is not adjusted (the natural residence time is about 0.3h).
[0045] The remaining steps are exactly the same as in Example 1.
[0046] Testing revealed that the pyrolysis products consisted of 15% pyrolysis gas, 17% pyrolysis oil, and 68% pyrolysis char. The pyrolysis gas composition (by volume) was 15% hydrogen, 30% methane, 19% carbon dioxide, 12% carbon monoxide, and 24% C2-C3 hydrocarbons. The pyrolysis gas had a high tar content, which could easily cause pipeline blockage. Furthermore, there was no catalyst recycling process, resulting in high operating costs.
[0047] like Figure 2As shown, compared with the conventional pyrolysis process of Comparative Example 1, Example 1, through the synergistic regulation of high-temperature pyrolysis above 650℃, in-situ CaO catalysis, and a long residence time of 1.5h, increases the pyrolysis gas yield by 9%, increases the hydrogen content by 16%, reduces the carbon dioxide content by 15%, and reduces the C2-C3 hydrocarbon content by 19%, while avoiding the problems of pyrolysis gas loss and tar blockage, and the catalyst can be recycled.
[0048] Therefore, the present invention employs the above-mentioned method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge, thereby increasing the pyrolysis gas yield and hydrogen content, while reducing carbon dioxide emissions, and achieving efficient directional conversion of oily sludge into hydrogen-rich gas.
[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge, characterized in that, Includes the following steps: S1. Pretreatment of oily sludge: The oily sludge is dried and crushed to control the moisture content of the pretreated oily sludge to be ≤30%, the particle size to be ≤5mm, and the coefficient of variation of mixing uniformity to be ≤10%. S2. Pyrolysis of oily sludge: The pretreated oily sludge is fed into an integrated pyrolysis catalytic reactor, an inert atmosphere is introduced, the temperature is raised to 650~700℃, and the pyrolysis reaction is carried out at this temperature to generate pyrolysis gas, pyrolysis oil and pyrolysis char. S3. In-situ catalysis and long residence time directional conversion: The integrated pyrolysis catalytic reactor has a built-in CaO catalyst layer, and the residence time of the pyrolysis gas is controlled to 1.5h. At a temperature of 650~700℃, the pyrolysis gas and CaO catalyst are in full contact in situ, and a catalytic conversion reaction occurs. S4. Hydrogen-rich gas collection: Collect the converted hydrogen-rich gas through the hydrogen-rich gas collection unit; S5. Product separation and catalyst regeneration: Hydrogen-rich gas is separated and purified by membrane separation or PSA pressure swing adsorption to obtain hydrogen and methane, respectively.
2. The method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to claim 1, characterized in that, In S2, the inert atmosphere is nitrogen or argon with a purity ≥ 99.9%, and the flow rate is 5~20m³. 3 / h.
3. The method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to claim 1, characterized in that, In S3, the CaO catalyst layer has a catalyst particle size of 1~10mm and a specific surface area of 30~200m². 2 / g, the mass ratio of CaO catalyst loading to oily sludge is 0.5~2:1, and the CaO catalyst layer adopts a honeycomb structure.
4. The method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to claim 1, characterized in that, In S2, the heating rate is 5~10℃ / min.
5. The method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to claim 1, characterized in that, In S2, the pyrolysis gas includes hydrogen, methane, carbon dioxide, carbon monoxide, C2-C3 hydrocarbons, and tar vapor.
6. The method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to claim 1, characterized in that, In S4, the hydrogen-rich gas comprises the following volume percentage components: Hydrogen 30-31%, methane 41-43%, carbon dioxide 4-4.5%, carbon monoxide 17-19%, C2-C3 hydrocarbons 4-6%; The hydrogen-rich gas accounts for 24% of the total mass fraction of the pyrolysis products.
7. The method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to claim 1, characterized in that, Following S5, the process also includes the regeneration of the CaO catalyst, specifically: Using air as the regeneration medium, the regeneration temperature is 600~800℃, the regeneration time is 2~4h, and the catalytic activity recovery rate after regeneration is ≥90%.
8. The method for preparing hydrogen-rich gas by directional catalytic pyrolysis of oily sludge according to claim 1, characterized in that, In S2, the integrated pyrolysis catalytic reactor is equipped with a regenerative radiant tube, a spiral guide plate, a buffer chamber, and a second-layer circulation unit. The regenerative radiant tube is used for precise temperature control, the spiral guide plate is used to guide the directional flow of pyrolysis gas, the buffer chamber is used to balance the airflow, and the second-layer circulation unit is used for the regeneration and cyclic catalysis of CaO catalyst.