Circulation type oil-based rock debris catalytic pyrolysis treatment system and method
Through the cyclic oil bedrock cutting catalytic pyrolysis treatment system, the problem of high yields of heavy oil components and coke in oil bedrock cutting pyrolysis is solved, and efficient resource utilization and environmental safe disposal is achieved.
Patent Information
- Application Number
- CN202510530879.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2025-07-29
AI Technical Summary
In the pyrolysis process of oil bedrock cuttings in the prior art, the yield of heavy oil components and coke is high, the yield of pyrolytic oil decreases, the quality of recovered oil is poor, and the pyrolytic slag and catalyst are difficult to separate, resulting in environmental risks and low resource utilization efficiency.
The catalytic pyrolysis treatment system of cyclic oil bedrock cuttings is adopted to promote the cracking of heavy hydrocarbons through the pyrolysis section and the catalytic section through the segmented pyrolysis section and the catalytic section, and the contact time between the pyrolysis oil and gas and the catalyst is increased through the phasing condensation and cyclic pyrolysis method, and combined with the non-condensable gas as fuel-assisted heating, the catalyst is realized.
It improves the yield of light hydrocarbons in the recovered oil, reduces the oil content of oil-bedded rock residues, improves the quality of recovered oil, improves energy utilization efficiency, meets the disposal requirements of oil-containing solid waste, and reduces environmental risks.
Smart Images
Figure CN120383947A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of solid waste resource utilization, and particularly relates to a cyclic catalytic pyrolysis disposal system and method for oil-based cuttings. Background Art
[0002] Oil-based cuttings refer to solid waste generated by the contact between oil-based drilling fluid and formation rocks during oil / gas drilling and returned to the outside of the well together with the drilling fluid. At present, the annual output of oil-based cuttings in China has reached as high as 24.4 million cubic meters, and the output is increasing rapidly at a rate of millions of cubic meters per year. Oil-based cuttings are rich in heavy metals, benzene series, polycyclic aromatic hydrocarbons, alkali metal salts and other substances that are difficult to degrade and have biological toxicity, posing great environmental risks, and have been listed in the "National Hazardous Waste List" (waste category: HW08). As a typical type of hazardous waste, oil-based cuttings are difficult and costly to transport and dispose of, and improper disposal will cause serious harm to the ecological environment and human health. In addition, the average oil content of oil-based cuttings is 10-20%, which has significant resource recovery and utilization value.
[0003] Pyrolysis is to separate volatile and semi-volatile substances in oil-based cuttings from residues by high-temperature heating, to achieve efficient recovery of oil and gas products, and to simultaneously realize the harmless disposal and resource utilization of oil-based cuttings. However, since the oil-containing components in oil-based cuttings are mainly mineral oils, condensation reactions are prone to occur during conventional pyrolysis, resulting in problems such as increased yields of heavy oil components and coke, decreased yield of pyrolysis oil, and poor quality of recovered oil. Therefore, it is necessary to provide a cyclic catalytic pyrolysis disposal method for oil-based cuttings to solve the above problems. Summary of the Invention
[0004] The purpose of the present invention is to provide a cyclic catalytic pyrolysis disposal system and method for oil-based cuttings, which perform segmented cyclic pyrolysis through a pyrolysis section and a catalytic section, promote the cracking of heavy hydrocarbons, increase the yield of light hydrocarbons in the recovered oil, thereby improving the quality of the recovered oil, and at the same time can reduce the oil content of the oil-based cuttings residue after pyrolysis, and is also conducive to the separation of the catalyst and the pyrolysis residue, realizing the recycling and reuse of the catalyst.
[0005] To achieve the above purpose, the present invention provides a cyclic catalytic pyrolysis disposal system for oil-based cuttings, including a feeding unit, a pyrolysis unit, a condensation unit and a recovery unit connected in sequence;
[0006] The pyrolysis unit includes a pyrolysis section and a catalytic section. The pyrolysis section is provided with a feeding port connected to the feeding unit, a discharging port connected to the recovery unit, and an air outlet and an air inlet connected to the catalytic section; the catalytic section is also provided with an air inlet and an air outlet connected to the condensation unit;
[0007] A catalyst is placed in the catalytic section for catalyzing the cracking of the pyrolysis oil and gas generated in the pyrolysis section, and is separated from the pyrolysis slag in the pyrolysis section at the same time;
[0008] The condensation unit includes a primary condenser and a secondary condenser connected to the catalytic section in sequence. The discharge port of the secondary condenser is connected to the recovery unit; the condensation temperature of the primary condenser is higher than that of the secondary condenser; the primary condenser is used to condense the heavy components in the pyrolysis gas from the catalytic section and return them to the catalytic section for continuous catalytic cracking, and the hydrocarbon substances and non-condensable gases are obtained after condensation by the secondary condenser.
[0009] Further, the temperature of the pyrolysis section and the catalytic section is 400°C to 600°C, the condensation temperature of the primary condenser is 160°C to 180°C, and the condensation temperature of the secondary condenser is 20°C to 40°C.
[0010] Further, the condensation unit further includes a heat exchanger disposed between the catalytic section and the primary condenser for exchanging heat between the pyrolysis gas output from the catalytic section and the heavy components returned from the primary condenser.
[0011] Further, the catalytic pyrolysis treatment system further includes a gas storage tank connected to the secondary condenser for storing the non-condensable gas; the gas storage tank is also connected to the pyrolysis section and the catalytic section respectively for using the non-condensable gas as fuel for the pyrolysis section and the catalytic section to assist in heating up;
[0012] And / or, the recovery unit includes a pyrolysis slag storage area connected to the pyrolysis section and a recovered oil storage tank connected to the secondary condenser.
[0013] Further, the catalytic pyrolysis treatment system further includes a pretreatment unit, and the pretreatment unit includes a vibrating screen, a crusher, and a mixer connected in sequence; the vibrating screen is used for screening the oil-based cuttings and directly conveying the undersize material to the mixer, and the oversize material is conveyed to the crusher, and after being crushed, it is conveyed to the mixer; the mixer is used for mixing the materials evenly and then conveying them to the feeding unit.
[0014] The present invention also provides a cyclic catalytic pyrolysis treatment method for oil-based cuttings, which uses the cyclic catalytic pyrolysis treatment system described in any one of the above, and includes the following steps:
[0015] S1. Open the air outlet and air inlet between the pyrolysis section and the catalytic section, and place a catalyst in the catalytic section; convey the oil-based cuttings to the pyrolysis section, and carry out pyrolysis in an inert atmosphere. The pyrolysis oil and gas generated by pyrolysis enter the catalytic section through the air outlet for catalytic cracking;
[0016] S2. The pyrolysis gas generated by catalytic cracking then enters the pyrolysis section for pyrolysis. After circulating and processing in the pyrolysis section and the catalytic section for a preset time, the pyrolysis gas is transported from the catalytic section to the condensation unit. The heavy components are condensed and then returned to the catalytic section for continuous catalytic cracking, and the hydrocarbon substances and non-condensable gases are condensed and separated for recovery.
[0017] Further, the temperatures of the pyrolysis section and the catalytic section are 400°C to 600°C, and the preset time for cyclic processing is 40 min to 60 min.
[0018] And / or, the condensation temperature of the primary condenser is 160°C to 180°C, and the condensation temperature of the secondary condenser is 20°C to 40°C.
[0019] Further, step S2 further includes: transporting the pyrolysis gas from the catalytic section to a heat exchanger first, and then entering the primary condenser of the condensation unit. The heavy components returned from the primary condenser are heat-exchanged with the pyrolysis gas in the heat exchanger and then enter the catalytic section.
[0020] Further, step S1 further includes screening, crushing, and uniformly mixing the oil-based cuttings, and then transporting them to the pyrolysis section.
[0021] And / or, the non-condensable gas generated after condensation in the secondary condenser is used as fuel and transported to the pyrolysis section and the catalytic section for auxiliary heating.
[0022] Further, it further includes: discharging the pyrolysis slag generated in the pyrolysis section to the pyrolysis slag storage area, and heating and regenerating the catalyst in the catalytic section.
[0023] The catalyst includes one or more of molecular sieve catalysts, noble metal catalysts, sulfide catalysts, and nickel-based catalysts.
[0024] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following technical advantages are mainly possessed:
[0025] 1. The circulating oil-based cuttings catalytic pyrolysis disposal system provided by the present invention utilizes the advantages of catalytic pyrolysis to promote the cracking of heavy components. At the same time, by using the methods of fractional condensation and cyclic pyrolysis, the heavy hydrocarbon components repeatedly enter the catalytic section for pyrolysis, increasing the contact time between the pyrolysis oil and gas and the catalyst. Furthermore, the content of light hydrocarbons in the pyrolysis oil is greatly increased, improving the quality of the recovered oil. At the same time, the oil content in the residue of the oil-based cuttings after cyclic pyrolysis is significantly reduced (the oil content in the residue < 1%), meeting the disposal requirements of oil-containing solid waste and reducing the environmental risk of oil-based cuttings.
[0026] 2. The present invention recovers the non-condensable combustible gas generated by pyrolysis as fuel to assist in heating the pyrolysis unit. At the same time, heat is recovered by heat-exchanging the pyrolysis oil and gas with the heavy hydrocarbons in the primary condenser, greatly improving the energy utilization efficiency of the entire pyrolysis system.
[0027] 3. By performing staged cyclic pyrolysis on the pyrolysis stage and the catalytic stage, placing the catalyst only in the catalytic stage, and having the pyrolysis slag mainly present in the pyrolysis stage, the present invention can overcome the problems of difficult separation between the pyrolysis slag and the catalyst and the influence of the pyrolysis slag on the catalyst activity, thereby improving the catalytic efficiency and facilitating the recycling and reuse of the catalyst. Description of the Drawings
[0028] Figure 1 is a process flow diagram of a cyclic oil-based cuttings catalytic pyrolysis treatment method.
[0029] Figure 2 is a schematic diagram of a cyclic oil-based cuttings catalytic pyrolysis treatment method.
[0030] In all the drawings, the same reference numerals are used to represent the same elements or structures, where:
[0031] 1 - Oil-based cuttings storage tank; 2 - Screw pump; 3 - Linear vibrating screen; 4 - Jaw crusher; 5 - Twin-shaft screw mixer; 6 - Bucket elevator; 7 - Cylindrical silo; 8 - Feed pump; 9 - Rotary kiln pyrolysis furnace; 91 - Pyrolysis stage; 92 - Catalytic stage; 10 - Heat exchanger; 11 - Gas storage tank; 12 - Primary condenser; 13 - Secondary condenser; 14 - Recycled oil storage tank; 15 - Oil-based cuttings pyrolysis slag storage area. Detailed Embodiments
[0032] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0033] Please refer to Figure 1 and 2 , the present invention provides a cyclic oil-based cuttings catalytic pyrolysis treatment system, including a feeding unit, a pyrolysis unit, a condensation unit, and a recovery unit connected in sequence;
[0034] The pyrolysis unit includes a pyrolysis stage 91 and a catalytic stage 92. The pyrolysis stage 91 is provided with a feeding port connected to the feeding unit, a discharging port connected to the recovery unit, and an air outlet and an air inlet connected to the catalytic stage 92; the catalytic stage 92 is further provided with an air inlet and an air outlet connected to the condensation unit;
[0035] The catalytic stage 92 is provided with a catalyst for catalyzing the cracking of the pyrolysis oil and gas generated in the pyrolysis stage 91 and separating from the pyrolysis slag in the pyrolysis stage 91;
[0036] The condensation unit includes a primary condenser 12 and a secondary condenser 13 that are sequentially connected to the catalytic section 92. The discharge port of the secondary condenser 13 is connected to the recovery unit; the condensation temperature of the primary condenser 12 is higher than that of the secondary condenser 13; the primary condenser 12 is used to condense the heavy components in the pyrolysis gas from the catalytic section 92 and return them to the catalytic section 92 for continued catalytic cracking, and the secondary condenser 13 obtains hydrocarbon substances and non-condensable gases after condensation.
[0037] Among them, both the pyrolysis section 91 and the catalytic section 92 adopt a rotary kiln pyrolysis furnace 9. The recovery unit includes an oil-based cuttings pyrolysis slag storage area 15 connected to the pyrolysis section 91 and a recovered oil storage tank 14 connected to the secondary condenser 13.
[0038] The secondary condenser 13 is also connected to a gas storage tank 11 for storing non-condensable gases (mainly composed of CH4, CO, CO2, H2, and hydrocarbons of C2-C5); the gas storage tank 11 is also respectively connected to the pyrolysis section 91 and the catalytic section 92 for using the non-condensable gases as fuel to assist in heating up the pyrolysis section 91 and the catalytic section 92. This greatly improves the energy utilization efficiency of the entire pyrolysis system and saves energy.
[0039] The condensation temperature of the primary condenser is set to 160°C to 180°C for recovering heavy hydrocarbons; the condensation temperature of the secondary condenser is set to 20°C to 40°C for recovering light hydrocarbons.
[0040] The condensation unit further includes a heat exchanger 10 disposed between the catalytic section 92 and the primary condenser 12 for exchanging heat between the pyrolysis gas output from the catalytic section 92 and the heavy components returned from the primary condenser 12. The heavy hydrocarbons collected from the primary condenser 12 return to the catalytic pyrolysis cycle along the pipeline and exchange heat with the pyrolysis oil and gas from the catalytic section 92, and the flow direction of the heavy hydrocarbons is opposite to that of the pyrolysis oil and gas flow. The heavy hydrocarbons become steam after heat exchange and enter the catalytic section 92; the pyrolysis oil and gas are cooled by the heavy hydrocarbons before condensation, improving the subsequent condensation efficiency.
[0041] In particular, the catalytic pyrolysis disposal system further includes a pretreatment unit, and the pretreatment unit includes a linear vibrating screen 3, a jaw crusher 4, and a double-shaft spiral mixer 5 that are sequentially connected; the linear vibrating screen 3 is used to screen the oil-based cuttings and directly convey the screened materials to the double-shaft spiral mixer 5, and the oversize materials are conveyed to the jaw crusher 4, and after crushing, they are conveyed to the double-shaft spiral mixer 5; the double-shaft spiral mixer 5 is used to mix the materials evenly and then convey them to the feeding unit.
[0042] The linear vibrating screen 3 is connected to the oil-based cuttings storage tank 1 through a screw pump 2. The double-shaft screw mixer 5 is connected to the silo 7 through a bucket elevator 6 for storing the uniformly mixed materials. The silo 7 is connected to the pyrolysis section 91 through a feed pump 8.
[0043] The heating rate of the pyrolysis section 91 is 10 °C / min, the pyrolysis temperature is 400 °C - 600 °C, and the heat preservation time is 40 min - 60 min to ensure the volatilization and cracking of hydrocarbon substances. The inert gases selected are nitrogen, carbon dioxide, argon, etc.
[0044] The catalysts used include one or more of molecular sieve catalysts, noble metal catalysts, sulfide catalysts, and nickel-based catalysts. For example, ZSM-5 type zeolite molecular sieve.
[0045] A cyclic catalytic pyrolysis treatment method for oil-based cuttings includes the following steps:
[0046] S1, Pretreat the oil-based cuttings: First, conduct a filtration treatment to screen out the impurities and large-particle oil-based cuttings, crush the large-particle oil-based cuttings, and then stir and mix the crushed oil-based cuttings to improve the fluidity of the oil-based cuttings and prevent blockage of the conveying pipeline.
[0047] S2, Send the oil-based cuttings into the pyrolysis section through a conveying pipeline for pyrolysis, and ensure that the pyrolysis equipment is in a sealed state during the entire feeding process of the oil-based cuttings to prevent air from entering and affecting the pyrolysis effect. At the same time, use an inert gas to remove the air in the pipeline and the device, so that the oil-based cuttings are pyrolyzed in an inert atmosphere.
[0048] S3, The oil and gas generated in the pyrolysis section are sent into the catalytic section with the inert gas, and the temperature of the catalytic section is the same as that of the pyrolysis section. Among them, the pyrolyzed oil and gas come into contact with the catalyst and undergo a catalytic reaction to promote the cracking of hydrocarbons. The catalytic pyrolyzed oil and gas return to the pyrolysis section with the inert gas to continue pyrolysis, completing the first catalytic pyrolysis cycle.
[0049] S4, Set to terminate after cycling a certain number of times, and then the pyrolyzed oil and gas enter the condenser. A two-stage fractional condensation (the temperature drops step by step) is set in the condenser. Most of the heavy hydrocarbons are collected in the first-stage condensation section, while the remaining light hydrocarbon components are collected in the second-stage condensation section.
[0050] S5, The heavy hydrocarbons collected from the first-stage condensation section are heat-exchanged with the high-temperature pyrolyzed oil and gas from the pyrolysis cycle to make the heavy hydrocarbons volatilize again and return to the catalytic section for further cracking; the light hydrocarbons collected from the second-stage condensation section enter the recovered oil storage tank.
[0051] S6, The non-condensable combustible gas is sent into the pyrolysis section as fuel gas to assist in heating up.
[0052] S7, Recover the pyrolysis slag of the oil-based cuttings after pyrolysis treatment.
[0053] For the pretreatment of oil-based cuttings in S1, solids with a particle size greater than 5 mm are screened out by a vibrating screen, crushed by a crusher, and finally the oil-based cuttings are stirred and mixed by a double-shaft screw mixer.
[0054] Example 1
[0055] S1: The oil-based cuttings are pumped out from the oil-based cuttings storage tank 1 (meeting the "Pollution Control Standard for Hazardous Waste Storage" GB 18597-2023) by a screw pump 2, transported through a pipeline to a linear vibrating screen 3 to screen out solids with a particle size greater than 5 mm, then leave from the oversize outlet of the vibrating screen, and are sent to a jaw crusher 4 for crushing. The crushed material and the remaining oil-based cuttings enter the mixer from above a double-shaft screw mixer 5 for stirring and mixing to improve the fluidity of the oil-based cuttings and prevent the transportation pipeline from being blocked. Finally, it leaves from the discharge port of the mixer to complete the pretreatment of the oil-based cuttings. The pretreated oil-based cuttings are sent to a cylindrical silo 7 for storage by a bucket elevator 6.
[0056] S2: A two-stage electric rotary kiln pyrolysis furnace 9 is selected as the oil-based cuttings pyrolysis device. The first stage is the pyrolysis section, whose feed inlet and discharge outlet handle the entry and exit of the oil-based cuttings. At the same time, there is also an air outlet and an air inlet respectively connected to the air inlet and air outlet of the catalytic section; the second stage is the catalytic section, whose air inlet and air outlet are used to handle the entry and exit of the pyrolysis oil and gas.
[0057] Specifically, the pyrolysis furnace where the catalytic section is located is provided with two air inlets and two air outlets. One of the air outlets is connected to the pyrolysis furnace of the pyrolysis section for circulating catalytic pyrolysis, and the other air outlet is used to send the pyrolysis oil and gas to the condensation section when the circulation terminates. Only one of the two air outlets is in the open state at the same time. For the two air inlets, one is connected to the pyrolysis section, and the other is connected to a heat exchanger 10 to receive the heavy hydrocarbon steam from a primary condenser 12. To prevent air from entering the pyrolysis device, the entire feeding process should be kept sealed. Before the oil-based cuttings are fed, nitrogen is continuously introduced into the pyrolysis device to remove the air in the device, and the oil-based cuttings are sent to the pyrolysis furnace for pyrolysis by a feed pump 8.
[0058] S3: The pyrolysis furnace is heated by gas, the heating rate of the pyrolysis section is set at 10 °C / min, the pyrolysis temperature is 400 °C to 600 °C, and the holding time is 40 min to 60 min. Ensure that hydrocarbon substances volatilize and crack, and the pyrolysis oil and gas analyzed come out from the air outlet of the pyrolysis chamber and enter the catalytic section for catalytic pyrolysis through a fan pipeline. Heat insulation materials are set on the pipeline to prevent heat dissipation.
[0059] S4. The temperature condition in the catalytic section is the same as that in the pyrolysis section. ZSM-5 zeolite molecular sieve is selected as the catalyst. In this process, the pyrolysis oil and gas come into contact with the catalyst to undergo catalytic reactions, cracking heavy hydrocarbons into light hydrocarbons and increasing the content of light components in the oil and gas. After catalytic cracking, the oil and gas return to the pyrolysis section through a pipeline connecting the catalytic section and the pyrolysis section by a blower, forming a cycle. Steps S3 and S4 are repeated. After the above cycle is carried out a certain number of times, the cycle is terminated, the air inlet of the pipeline connecting the catalytic section and the pyrolysis section is closed, and the air outlet connecting to the condensation section is opened. The pyrolysis oil and gas leave from this air outlet, enter the condenser after passing through heat exchanger 10.
[0060] S5. The condensation section consists of two condensers with different temperature circulating media. The condensation temperature of the primary condenser 12 is 160°C - 180°C; the condensation temperature of the secondary condenser 13 is 20°C - 40°C, and the temperature distribution decreases step by step. When the pyrolysis oil and gas pass through the primary condenser 12, heavy components are condensed and leave the condensation section through a pipeline to return to the catalytic section for further catalytic cracking; when the pyrolysis oil and gas pass through the secondary condenser 13, the remaining hydrocarbon substances (mainly light hydrocarbons) are recovered into the recovered oil storage tank 14, and the remaining non-condensable combustible gases (mainly composed of CH4, CO, CO2, H2 and C2 - C5 hydrocarbons) will pass through the pipeline to the gas storage tank 11.
[0061] S6. Before the heavy hydrocarbons recovered in the condensation section return to the pyrolysis furnace through a pipeline, the heavy hydrocarbons and the pyrolysis oil and gas from the pyrolysis furnace exchange heat in heat exchanger 10. By absorbing the heat in the pyrolysis oil and gas, the heavy hydrocarbons are regenerated into steam, saving the energy consumed in the re-volatilization process of the heavy hydrocarbons in the pyrolysis furnace; after the pyrolysis oil and gas are cooled down, the condensation efficiency in the subsequent condensation section can be improved.
[0062] S7. The non-condensable combustible gases recovered from the secondary condenser 13 are stored in the gas storage tank 11 and can be transported to the combustion chamber of the pyrolysis furnace as fuel for combustion-assisted heating.
[0063] S8. After pyrolysis, the pyrolysis slag of oil-based cuttings is discharged from the discharge port of the pyrolysis furnace, and then conveyed to the storage area 15 of the pyrolysis slag of oil-based cuttings by a conveyor belt. After pyrolysis treatment, the oil content of the oil-based cuttings is less than 1%, meeting the emission requirements in GB 31571-2015 "Emission Standards for Pollutants in the Petroleum Chemical Industry", and can be used for building fillers or directly landfilled in the follow-up.
[0064] Example 2
[0065] Based on Example 1, the following improvements are made in this example:
[0066] In S1, during the pretreatment process, the oil-based cuttings are dried and preheated, and the double-shaft screw mixer is replaced with a dehumidifying mixer with end drying.
[0067] In S2, replacing the inert gas nitrogen with carbon dioxide can not only provide the inert atmosphere required for pyrolysis, but also utilize the carbon dioxide gas recovered from the gas storage tank.
[0068] In S7, a flow meter and a flow control valve are installed on the pipeline connecting the gas storage tank and the pyrolysis furnace. The flow control valve is adjusted according to the heat load required by the pyrolysis furnace to control the flow rate of the non-condensable combustible gas, so as to achieve more efficient utilization of the non-condensable combustible gas.
[0069] In S8, the pyrolysis slag of oil-based cuttings is heat-exchanged and cooled by the low-temperature non-condensable combustible gas of the secondary condenser 13 before being sent to the storage area 15 of the pyrolysis slag of oil-based cuttings.
[0070] In summary, the present invention pre-treats oil-based cuttings, including screening out large-particle oil-based cuttings for crushing and stirring, and then sending them into the pyrolysis section for heating to raise the temperature of the oil-based cuttings to the volatilization and cracking temperatures of different hydrocarbon components. The pyrolysis oil and gas volatilized are sent into the catalytic section with the carrier gas, and after being catalytically decomposed by the catalyst, they are sent back into the pyrolysis section to complete one cycle. After the cycle reaches a certain number of times, the cycle is terminated. Then, the pyrolysis oil and gas enter the fractional condensation section to separate the heavy hydrocarbon components and the light hydrocarbon components therein. The heavy hydrocarbon components are re-sent back to the catalytic pyrolysis section for circulation, while the light hydrocarbon components enter the recovered oil storage tank. This method not only utilizes the advantages of catalytic pyrolysis to promote the cracking of heavy components, but also makes the catalytic reaction more sufficient by means of cyclic pyrolysis, improves the content of light components in the recovered oil, thereby improving the quality of the recovered oil, and the oil content of the treated oil-based cuttings is less than 1%, meeting the disposal requirements of oil-containing solid waste and eliminating environmental hazards. It not only solves the environmental pollution problem of oil-based cuttings, but also realizes the efficient resource utilization of petroleum hydrocarbons.
[0071] It is easy for those skilled in the art to understand that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A cyclic oil-based cuttings catalytic pyrolysis disposal system, characterized in that, It includes a feeding unit, a pyrolysis unit, a condensation unit, and a recovery unit connected in sequence; The pyrolysis unit includes a pyrolysis section and a catalytic section. The pyrolysis section is provided with a feed inlet connected to the feeding unit, a discharge outlet connected to the recovery unit, and an air outlet and an air inlet connected to the catalytic section; The catalytic section is also provided with an air inlet and an air outlet connected to the condensation unit; A catalyst is placed in the catalytic section for catalyzing the cracking of the pyrolysis oil and gas generated in the pyrolysis section, and at the same time is separated from the pyrolysis slag in the pyrolysis section; The condensation unit includes a primary condenser and a secondary condenser connected to the catalytic section in sequence. The discharge outlet of the secondary condenser is connected to the recovery unit; The condensation temperature of the primary condenser is higher than that of the secondary condenser; The primary condenser is used to condense the heavy components in the pyrolysis gas of the catalytic section and return them to the catalytic section for continuous catalytic cracking, and the hydrocarbon substances and non-condensable gases are obtained after condensation by the secondary condenser.
2. The circulating oil-based rock cuttings catalytic pyrolysis treatment system according to claim 1 is characterized in that: The temperature of the pyrolysis section and the catalytic section is 400°C to 600°C, the condensation temperature of the primary condenser is 160°C to 180°C, and the condensation temperature of the secondary condenser is 20°C to 40°C.
3. The circulating oil-based rock cuttings catalytic pyrolysis treatment system according to claim 1 is characterized in that: The condensation unit further includes a heat exchanger disposed between the catalytic section and the primary condenser for heat-exchanging the pyrolysis gas output from the catalytic section and the heavy components returned from the primary condenser.
4. The catalytic pyrolysis treatment system for cyclic oil-based cuttings according to any one of claims 1-3, characterized in that, The catalytic pyrolysis treatment system further includes a gas storage tank connected to the secondary condenser for storing the non-condensable gas; The gas storage tank is also connected to the pyrolysis section and the catalytic section respectively for using the non-condensable gas as the fuel for the pyrolysis section and the catalytic section to assist in heating up; And / or, the recovery unit includes a pyrolysis slag storage area connected to the pyrolysis section and a recovered oil storage tank connected to the secondary condenser.
5. The catalytic pyrolysis treatment system for cyclic oil-based cuttings according to any one of claims 1-3, characterized in that, The catalytic pyrolysis treatment system further includes a pretreatment unit, and the pretreatment unit includes a vibrating screen, a crusher, and a mixer connected in sequence; The vibrating screen is used for screening the oil-based cuttings, and directly conveying the undersize materials to the mixer, and the oversize materials are conveyed to the crusher, and after being crushed, they are conveyed to the mixer; The mixer is used for mixing the materials evenly and then conveying them to the feeding unit.
6. A catalytic pyrolysis disposal method for cyclic oil-based cuttings, characterized in that, Using the circulating oil-based cuttings catalytic pyrolysis treatment system according to any one of claims 1-5, it includes the following steps: S1. Open the air outlet and the air inlet between the pyrolysis section and the catalytic section, and put a catalyst in the catalytic section; Convey the oil-based cuttings to the pyrolysis section, and carry out pyrolysis in an inert atmosphere. The pyrolysis oil and gas generated by pyrolysis enter the catalytic section through the air outlet for catalytic cracking; S2. The pyrolysis gas generated by catalytic cracking enters the pyrolysis section for pyrolysis again. After circulating and processing in the pyrolysis section and the catalytic section for a preset time, the pyrolysis gas is conveyed from the catalytic section to the condensation unit. The heavy components are condensed and returned to the catalytic section for continuous catalytic cracking, and the hydrocarbon substances and non-condensable gases are separated and recovered after condensation.
7. The catalytic pyrolysis disposal method for cyclic oil-based cuttings according to claim 6, characterized in that, The temperature of the pyrolysis section and the catalytic section is 400°C to 600°C, and the preset time for circulating treatment is 40 min to 60 min; And / or, the condensation temperature of the primary condenser is 160°C to 180°C, and the condensation temperature of the secondary condenser is 20°C to 40°C.
8. The catalytic pyrolysis disposal method for cyclic oil-based cuttings according to claim 6, characterized in that, Step S2 further includes: conveying the pyrolysis gas from the catalytic section to the heat exchanger first, and then entering the primary condenser of the condensation unit. The heavy components returned by the primary condenser are heat-exchanged with the pyrolysis gas in the heat exchanger and then enter the catalytic section.
9. The catalytic pyrolysis treatment method for cyclic oil-based cuttings according to claim 6, characterized in that, Step S1 further includes screening and crushing the oil-based cuttings, mixing them evenly, and then conveying them to the pyrolysis section; And / or, the non-condensable gas generated after condensation by the secondary condenser is used as fuel and conveyed to the pyrolysis section and the catalytic section for auxiliary heating.
10. The catalytic pyrolysis disposal method for cyclic oil-based cuttings according to any one of claims 6-9, characterized in that, It further includes: Discharging the pyrolysis slag generated in the pyrolysis section to the pyrolysis slag storage area, and heating and regenerating the catalyst in the catalytic section; The catalyst includes one or more of molecular sieve catalysts, noble metal catalysts, sulfide catalysts, and nickel-based catalysts.