Oil sand dry distillation flue gas gradient treatment and resource utilization integrated system
Through the coordinated processing of cascade purification and resource recycling modules, the problems of high investment, energy consumption and resource waste in flue gas treatment in the oil sands distillation process are solved, efficient pollutant purification and resource recovery are achieved, and the cost and environmental risks of oil sands mining are reduced.
Patent Information
- Application Number
- CN202511059829.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2025-09-12
AI Technical Summary
Flue gas treatment in traditional oil sands distillation process has problems of high investment, high energy consumption, waste of resources and environmental pollution. It fails to effectively utilize the carbon dioxide and nitrogen resources in the flue gas, and the desulfurization waste residue is difficult to recycle as a resource.
A cascade purification module is used for dust removal, heat exchange and coordinated removal of acidic gases. The resource recycling module is combined to recover sulfur and high-purity hydrogen. The distributed control module is used for collaborative operation to achieve cascade treatment and resource utilization of flue gas.
It achieves ultra-low emissions of pollutants such as dust, H2S, and NOx, recovers high-purity CO2 for oil recovery, recycles sulfur with a purity of ≥99.5% as a resource, and uses high-purity hydrogen and nitrogen for oilfield applications, significantly reducing costs and environmental risks and building a multi-closed-loop system.
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Figure CN120618142A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of flue gas treatment systems, and in particular relates to an integrated system for cascade treatment and resource utilization of oil sand retorting flue gas. Background Art
[0002] In the traditional oil sands distillation process, flue gas treatment faces the following deficiencies: To meet environmental emission requirements, independent, high-investment dust removal, desulfurization, and wastewater treatment facilities, such as electrostatic precipitators, wet desulfurization towers, and chemical sedimentation tanks, are required. These facilities not only occupy a large area but also consume a large amount of reagents (such as limestone and NaOH) and energy during operation and maintenance, resulting in high treatment costs. The medium-high temperature waste heat of 200-400°C carried by the retorting flue gas is usually directly discharged, resulting in a waste of heat energy equivalent to about 30-50kW·h / ton of oil sands; The high concentration of 10-20% carbon dioxide contained in the flue gas is not targeted for enrichment, but is simply diluted before being discharged, which not only increases carbon emission pressure but also misses its value as an efficient oil displacement agent. The sulfur-containing waste residues generated in the desulfurization process, such as sulfur paste and calcium sulfate sludge, are difficult to utilize as resources due to their low purity and high impurities. They need to be disposed of in landfills as hazardous waste, and there is a long-term environmental risk of heavy metal leaching and contaminating the soil and groundwater.
[0003] This "treatment-and-disposal" model creates a vicious cycle of investment, energy consumption, pollution, and resource waste, seriously restricting the benefits of green development of oil sands.
[0004] In addition, the hydrogen-rich tail gas produced by the traditional Claus process for sulfur recovery contains 25-30% H2, which is directly incinerated and discharged, failing to efficiently utilize its fuel value; the nitrogen generated during the denitrification process is also directly discharged, failing to match the oil field's stable demand for inert gas, resulting in secondary waste of resources.
[0005] Based on this, an integrated system for cascade treatment and resource utilization of oil sands retorting flue gas was proposed. Summary of the Invention
[0006] The technical problem to be solved by the present invention is to provide an integrated system for cascade treatment and resource utilization of oil sands retorting flue gas in view of the above-mentioned deficiencies in the prior art, so as to solve the problems raised in the above-mentioned background technology.
[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: an integrated system for cascade treatment and resource utilization of oil sands retorting flue gas, including a cascade purification module, a resource recycling module and a distributed control module; The dry distillation flue gas is sent to the cascade purification module, and after dust removal, heat exchange and acid gas collaborative removal in the cascade purification module, sulfamine-rich liquid, purified flue gas and denitrified by-product gas are generated; Among them, the sulfamine-rich liquid is processed by the resource recycling module to obtain industrial sulfur; The purified flue gas is liquefied and purified in the resource recycling module and then stored for oil recovery; After deoxidation and drying in the resource recycling module, the denitrified by-product gas is compressed, stored, and then transported to the oil field for use in the gas phase sealing protection of the nitrogen storage tank and the safe purging of the process pipeline. The distributed control module is used to control the coordinated operation of the cascade purification module and the resource recycling module.
[0008] As a further illustration of the present invention, the step purification module includes a cyclone separator and a high temperature resistant ceramic fiber filter, and the dry distillation flue gas is dust-removed through the cyclone separator and the high temperature resistant ceramic fiber filter.
[0009] As a further illustration of the present invention, the cascade purification module further includes a waste heat recovery unit, and the dry distillation flue gas that has undergone dust removal treatment is sent to the waste heat recovery unit to complete heat exchange treatment.
[0010] As a further illustration of the present invention, the waste heat recovery unit is a multi-channel plate heat exchanger.
[0011] As a further illustration of the present invention, the cascade purification module also includes an amine desulfurization tower and a catalytic oxidation denitrification tower. The dry distillation flue gas that has undergone heat exchange treatment is first passed through the amine desulfurization tower to remove hydrogen sulfide and then generate sulfur-rich amine liquid and primary treatment gas. The primary treatment gas is then passed through the catalytic oxidation denitrification tower to generate purified flue gas, denitrification by-product gas and water.
[0012] As a further illustration of the present invention, the resource recycling module includes a sulfur recovery unit. The sulfur-rich amine liquid is treated by the sulfur recovery unit to obtain industrial sulfur. The purity of the industrial sulfur is ≥99.5%, completing the closed cycle of sulfur resources.
[0013] As a further illustration of the present invention, the hydrogen-containing tail gas generated during the treatment process of the sulfur recovery unit is sent to a hydrogen purification unit, and after impurities are removed by the hydrogen purification unit, high-purity hydrogen with a purity of ≥99.9% is obtained, and the high-purity hydrogen is used for fuel replenishment.
[0014] As a further illustration of the present invention, the sulfur recovery unit is a Claus reactor, and the hydrogen purification unit is a PSA hydrogen extraction device.
[0015] As a further illustration of the present invention, the resource recycling module also includes a PSA membrane group and a liquefaction compression unit. The purified flue gas is purified by the PSA membrane group to obtain nitrogen with a purity of ≥97%, which is then sent to the liquefaction compression unit for liquefaction treatment and storage for future use.
[0016] As a further illustration of the present invention, the denitrification by-product gas is deoxygenated and dried to obtain industrial grade nitrogen with a purity of ≥98%.
[0017] Compared with the prior art, the present invention has the following advantages: Through the coordinated cooperation of the cascade purification module, the resource recycling module and the distributed control module, the present invention can complete the efficient purification and resource recovery of the distillation flue gas, and realize the ultra-low emission of pollutants such as dust, H2S, and NOx; the recovered CO2 with a purity of ≥97% is purified and liquefied for oil field oil displacement and storage, and the sulfur pollutants are converted into industrial sulfur with a purity of ≥99.5%. At the same time, the hydrogen produced as a by-product of the H2S sulfur production process is purified and recovered into hydrogen with a purity of ≥99.9% and used as an auxiliary fuel to replace part of the energy consumption; the high-purity nitrogen with a purity of ≥98% is compressed and used for sealing oil field nitrogen storage tanks and purging pipelines, further reducing external energy and material costs, and finally constructing a multi-closed-loop system of pollutant purification, resource recovery and energy self-circulation, significantly reducing the comprehensive cost and environmental risks of oil sands mining, and being economical and practical. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic diagram of the system of the present invention; Description of reference numerals: 1-Cyclone separator; 2-High-temperature resistant ceramic fiber filter; 3-Multi-channel plate heat exchanger; 4-Amine desulfurization tower; 5-Catalytic oxidation denitrification tower; 6-PSA membrane group; 7-Deaerator dryer; 8-Compressor; 9-Nitrogen storage tank; 10-Liquefaction compression unit; 11-Claus reactor; 12-PSA hydrogen extraction device. DETAILED DESCRIPTION
[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0020] Examples, such as Figure 1 As shown, the present invention provides a technical solution: an integrated system for cascade treatment and resource utilization of oil sands retorting flue gas, including a cascade purification module, a resource recycling module and a distributed control module; The dry distillation flue gas is sent to the cascade purification module, and after dust removal, heat exchange and acid gas collaborative removal in the cascade purification module, sulfamine-rich liquid, purified flue gas and denitrified by-product gas are generated; The step purification module includes a cyclone separator 1 and a high-temperature resistant ceramic fiber filter 2, and the dry distillation flue gas passes through the cyclone separator 1 and the high-temperature resistant ceramic fiber filter 2 to complete the dust removal process; The step purification module also includes a waste heat recovery unit, which is a multi-channel plate heat exchanger 3. The dry distillation flue gas after dust removal is sent to the waste heat recovery unit to complete the heat exchange treatment; The cascade purification module also includes an amine desulfurization tower 4 and a catalytic oxidation denitrification tower 5. The dry distillation flue gas after heat exchange treatment is first passed through the amine desulfurization tower 4 to remove hydrogen sulfide to generate sulfur-rich amine liquid and primary treatment gas. The primary treatment gas is then passed through the catalytic oxidation denitrification tower 5 to generate purified flue gas, denitrified by-product gas and water. Among them, the sulfamine-rich liquid is processed by the resource recycling module to obtain industrial sulfur; The resource recycling module includes a sulfur recovery unit, which is a Claus reactor 11. The sulfur-rich amine liquid is processed by the sulfur recovery unit to obtain industrial sulfur. The purity of the industrial sulfur is ≥99.5%, completing the closed cycle of sulfur resources. The hydrogen-containing tail gas generated during the treatment process of the sulfur recovery unit is sent to the hydrogen purification unit, which is a PSA hydrogen extraction device 12. After the impurities are removed by the hydrogen purification unit, high-purity hydrogen with a purity of ≥99.9% is obtained. The high-purity hydrogen is used for fuel replenishment.
[0021] The resource recycling module also includes a PSA membrane group 6 and a liquefaction compression unit 10. The purified flue gas is purified by the PSA membrane group 6 to obtain carbon dioxide with a purity of ≥97%, which is then sent to the liquefaction compression unit 10. After liquefaction treatment by the liquefaction compression unit 10, the carbon dioxide is stored for standby use. The liquefied high-purity carbon dioxide is transported to the oil field through a constant temperature and insulated pipeline and injected into the target oil reservoir after pressurization.
[0022] In oil reservoirs, carbon dioxide exerts multiple effects such as significant viscosity reduction, expansion and miscible displacement, effectively improving crude oil recovery and achieving geological storage of carbon dioxide, forming an integrated utilization of carbon resources for oil displacement and storage.
[0023] The denitrification by-product gas is deoxygenated and dried in the resource recycling module, which is specifically completed by the deoxygenation dryer 7 and the compressor 8. After deoxygenation and drying, the denitrification by-product gas reaches industrial-grade nitrogen with a purity of ≥98%, which is used for the gas phase space sealing protection of the nitrogen storage tank 9 and the safe purging operation of the process pipeline.
[0024] The distributed control module is used to control the coordinated operation of the cascade purification module and the resource recycling module.
[0025] Experimental example, the flow rate of the retort gas at the outlet of the retort furnace is 5000 Nm 3 / h, temperature 350℃, dust content 2 g / Nm 3 , H2S1.2%, CO215%, the dry distillation flue gas first passes through the cyclone separator 1, with a tangential flow rate of 20 m / s, centrifugally separates particles larger than 10 μm, and then passes through the high-temperature resistant ceramic fiber filter 2, with a pore size of 0.5 μm, and pulse backflushing to remove PM 2.5 Fine dust, reducing dust concentration to 8 mg / Nm 3 the following; The flue gas then enters the waste heat recovery unit and flows in the countercurrent to the oil sands raw material in the multi-channel plate heat exchanger 3. The dry distillation flue gas is cooled in steps from 350°C to 130°C, while the oil sands raw material is preheated from 25°C to 105°C, reducing the steam energy consumption of the drying system by 38%. Then it enters the amine desulfurization tower 4 and the catalytic oxidation denitrification tower 5; Amine desulfurization tower 4 concentration 30%, liquid-gas ratio 3 L / m 3 , 50℃, the H2S removal rate is increased to >99.5%, and sulfamine-rich liquid is generated. The temperature of catalytic oxidation denitrification tower 5 is 300℃, decomposing NOx into N2 / HO, with a denitrification rate of 93%; The final purified flue gas is purified to 96% CO2 at 1.5 MPa by the PSA membrane group 6, and then liquefied at -25°C by the liquefaction compression unit 10 to obtain 97% pure liquid CO2, which is stored in the 4 MPa nitrogen storage tank 9.
[0026] The sulfamine-rich liquid is transported to the Claus reactor 11, where the HS2 / O2 ratio is 2:1 and the temperature is 220°C. It undergoes two-stage catalytic conversion to produce liquid industrial sulfur with a purity of 99.8%, which meets the requirements of the national standard GB / T 2449-2021. The residual solution is then reinjected into the desulfurization tower for recycling. Claus reaction tail gas flow rate 120 Nm 3 / h, containing 28% H2, enters the PSA hydrogen extraction device 12 of the 4-tower cycle, with an operating pressure of 1.2 MPa, and produces 99.95% pure hydrogen, which is boosted to 0.8 MPa by the compressor and then transported to the retort burner, replacing 23% of natural gas consumption; The nitrogen produced by the denitrification by-product gas has a purity of 98.5% and a dew point of ≤-40°C. It is dehumidified by a two-stage deaerator dryer 7, pressurized to 15 MPa by a compressor 8 and stored in a buffer tank. It is then transported to the oilfield nitrogen storage tank sealing system through a constant pressure valve group, maintaining a pressure of 0.5 kPa and a pipeline purge unit. The gas consumption for a single purge is reduced to 60% of that of traditional liquid nitrogen.
[0027] At the same time, liquid CO2 is transported to the oilfield gas injection station through a -20°C constant-temperature pipeline and injected into the SAGD well group at a pressure of 18 MPa. Through viscosity reduction, the viscosity of the heavy oil is reduced from 4500 mPa·s to 1350 mPa·s, and expansion and miscible displacement effects are achieved, achieving an average daily increase of approximately 22 barrels of crude oil production per well.
[0028] The distributed control module monitors flue gas parameters in real time through the DCS system, dynamically adjusting the valve opening of the multi-channel plate heat exchanger 3 with a temperature control accuracy of ±5°C. The solution circulation volume of the amine desulfurization tower 4 is adaptively adjusted according to the H2S concentration, as is the separation and purge frequency of the PSA membrane group 6, ensuring a CO2 purification efficiency of >95%. At the same time, it adopts modular flange quick-connect layout, with 5000 Nm 3 Taking the processing scale of / h as an example, the total area is compressed to 200 m 2 The replacement time of the faulty module is ≤ 4 hours. The Karamay project has been verified to have an annual flue gas processing capacity of 43.8 million Nm 3 , produced 80 tons of sulfur, stored 12,000 tons of CO2, and reduced comprehensive operation and maintenance costs by 38%.
[0029] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.
[0030] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. An integrated system for cascade treatment and resource utilization of oil sands retorting flue gas, characterized by: It includes cascade purification module, resource recycling module and distributed control module; The dry distillation flue gas is sent to the cascade purification module, and after dust removal, heat exchange and acid gas collaborative removal in the cascade purification module, sulfamine-rich liquid, purified flue gas and denitrified by-product gas are generated; Among them, the sulfamine-rich liquid is processed by the resource recycling module to obtain industrial sulfur; The purified flue gas is liquefied and purified in the resource recycling module and then stored for oil recovery; After deoxidation and drying in the resource recycling module, the denitrified by-product gas is compressed, stored, and then transported to the oil field for use in the gas phase sealing protection of the nitrogen storage tank and the safe purging of the process pipeline. The distributed control module is used to control the coordinated operation of the cascade purification module and the resource recycling module.
2. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 1, characterized in that: The step purification module includes a cyclone separator and a high-temperature resistant ceramic fiber filter, and the dry distillation flue gas is dust-removed through the cyclone separator and the high-temperature resistant ceramic fiber filter.
3. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 2, characterized in that: The cascade purification module also includes a waste heat recovery unit, and the dry distillation flue gas that has undergone dust removal treatment is sent to the waste heat recovery unit to complete heat exchange treatment.
4. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 3, characterized in that: The waste heat recovery unit is a multi-channel plate heat exchanger.
5. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 3, characterized in that: The cascade purification module also includes an amine desulfurization tower and a catalytic oxidation denitrification tower. The dry distillation flue gas that has undergone heat exchange treatment first passes through the amine desulfurization tower to remove hydrogen sulfide and then generates sulfur-rich amine liquid and primary treatment gas. The primary treatment gas then passes through the catalytic oxidation denitrification tower to generate purified flue gas, denitrification by-product gas and water.
6. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 1, characterized in that: The resource recycling module includes a sulfur recovery unit. After the sulfur-rich amine liquid is treated by the sulfur recovery unit, industrial sulfur is obtained. The purity of the industrial sulfur is ≥99.5%, completing the closed cycle of sulfur resources.
7. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 6, characterized in that: The hydrogen-containing tail gas generated during the treatment process of the sulfur recovery unit is sent to the hydrogen purification unit. After the impurities are removed by the hydrogen purification unit, high-purity hydrogen with a purity of ≥99.9% is obtained. The high-purity hydrogen is used for fuel replenishment.
8. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 7, characterized in that: The sulfur recovery unit is a Claus reactor, and the hydrogen purification unit is a PSA hydrogen extraction device.
9. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 1, characterized in that: The resource recycling module also includes a PSA membrane group and a liquefaction compression unit. The purified flue gas is purified by the PSA membrane group to obtain carbon dioxide with a purity of ≥97%, which is then sent to the liquefaction compression unit for liquefaction treatment and storage for standby use.
10. The integrated system for cascade treatment and resource utilization of oil sands retorting flue gas according to claim 1, characterized in that: The denitrification by-product gas becomes industrial grade nitrogen with a purity of ≥98% after deoxygenation and drying.