Supercritical carbon dioxide （scCO2） microemulsion was formed by supercritical CO2, H20, sodium bis（2-ethylhexyl） sulfosuccinate （AOT, surfactant） and C2HsOH （co-surfactant） under pressures higher than 8 MPa a...Supercritical carbon dioxide （scCO2） microemulsion was formed by supercritical CO2, H20, sodium bis（2-ethylhexyl） sulfosuccinate （AOT, surfactant） and C2HsOH （co-surfactant） under pressures higher than 8 MPa at 45 ℃. The fundamental characteristics of the scCO2 microemulsion and the minimum miscibility pressure （MMP） with Daqing oil were investigated with a high-pressure falling sphere viscometer, a high-pressure interfacial tension meter, a PVT cell and a slim tube test. The mechanism of the scCO2 microemulsion for enhancing oil recovery is discussed. The results showed that the viscosity and density of the scCO2 microemulsion were higher than those of the scCO2 fluid at the same pressure and temperature. The results of interfacial tension and slim tube tests indicated that the MMP of the scCO2 microemulsion and crude oil was lower than that of the scCO2 and crude oil at 45 ℃. It is the combined action of viscosity, density and MMP which made the oil recovery efficiency of the scCO2 microemulsion higher than that of the scCO2 fluid.展开更多
Climate researchers have observed that the carbon dioxide （CO2） concentration in the atmosphere have been growing significantly over the past century. CO2 from energy represents about 75% of the greenhouse gas （GHG...Climate researchers have observed that the carbon dioxide （CO2） concentration in the atmosphere have been growing significantly over the past century. CO2 from energy represents about 75% of the greenhouse gas （GHG） emissions for Annex B （Developed） countries, and over 60% of global emissions. Because of impermeable cap rocks hydrocarbon reservoirs are able to sequester CO〉 In addition, due to high-demand for oil worldwide, injection of CO2 is a useful way to enhance oil production. Hence, applying an efficient method to co-optimize CO2 storage and oil production is vital. Lack of suitable optimization techniques in the past led most multi-objective optimization problems to be tackled in the same way as a single objective optimization issue. However, there are some basic differences between the multi and single objective optimization methods. In this study, by using a non- dominated sorting genetic algorithm （NSGA-II） for an oil reservoir, some appropriate scenarios are proposed based on simultaneous gas storage and enhanced oil recovery optimization. The advantages of this method allow us to amend production scenarios after implementing the optimization process, by regarding the variation of economic parameters such as oil price and CO2 tax. This leads to reduced risks and time duration of making new decisions based on upcoming situations.展开更多
The development and deployment of Carbon dioxide Capture and Storage （CCS） technology is a cornerstone of the Norwegian government＇s climate strategy. A number of projects are currently evaluated/planned along the ...The development and deployment of Carbon dioxide Capture and Storage （CCS） technology is a cornerstone of the Norwegian government＇s climate strategy. A number of projects are currently evaluated/planned along the Norwegian West Coast, one at Tjeldbergodden. COe from this project will be utilized in part for enhanced oil recovery in the Halten oil field, in the Norwegian Sea. We study a potential design of such a system. A combined cycle power plant with a gross power output of 832 MW is combined with CO2 capture plant based on a post-combustion capture using amines as a solvent. The captured CO2 is used for enhanced oil recovery （EOR）. We employ a hybrid life-cycle assessment （LCA） method to assess the environmental impacts of the system. The study focuses on the modifications and operations of the platform during EOR. We allocate the impacts connected to the capture of CO2 to electricity production, and the impacts connected to the transport and storage of CO2 to the oil produced. Our study shows a substantial reduction of the greenhouse gas emissions from power production by 80% to 75 g·（kW·h）^-1. It also indicates a reduction of the emissions associated with oil production per unit oil produced, mostly due to the increased oil production. Reductions are especially significant if the additional power demand due to EOR leads to power supply from the land.展开更多
In order to enhance coalbed methane recovery, taking a self-developed largecalesimulation system for the platform, a modeling experiment of driving CH_4 by CO_2 gasinjection was studied.The results of experiment indic...In order to enhance coalbed methane recovery, taking a self-developed largecalesimulation system for the platform, a modeling experiment of driving CH_4 by CO_2 gasinjection was studied.The results of experiment indicates that there is a significant lag effectof adsorption and desorption on gas, the gas pressure is changed more rapidly in theprocess of carbon dioxide adsorption of coal than methane adsorption of coal; After theinjection of carbon dioxide, compare with methane single desorption.In an early stage,speed and amount of methane single desorption are greater than the speed and amountof displacement desorption, the speed and amount of displacement desorption becamegreater.In the process of replacement, CH_4 concentration constantly declined, while CO_2concentration constantly rose.In the process of CO_2 gas injection, the temperature of coalhave been significantly increased, it is more beneficial to make CH_4 gas molecules becomefree from the adsorbed state when temperature is increased.Under the pressurestep-down at the same rate, using the method of CO_2 driving CH_4, compared with themethod of conventional pressure step-down, the desorption rate of CH_4 in coal can beraised about 2.13 times, at the same time, a lot of greenhouse gas CO_2 will also be buriedin the ground, there is a very significant environmental benefit.展开更多
This study reviews the recent progress and trends of carbon capture,utilization and storage(CCUS)technologies,with a particular focus on related policy orientations,technological status,and representative projects acr...This study reviews the recent progress and trends of carbon capture,utilization and storage(CCUS)technologies,with a particular focus on related policy orientations,technological status,and representative projects across North America,Europe,the Middle East,and China.The technical connotations of CCUS are elucidated,and the existing issues and challenges are identified from the perspectives of technology,economics,safety and system integration.The CO_(2) capture technologies are relatively mature;the emergence of novel processes such as direct air capture(DAC)and advanced materials such as metal-organic frameworks(MOFs)offer new choices for efficient capture,but issues related to high energy consumption and operational costs remain unresolved.The CO_(2) geological utilization has developed earlier,where breakthroughs rely on effective source matching,enhanced miscibility and increased swept volume.The CO_(2) chemical utilization exhibits broad market potential for producing high value-added products,and the development of catalytic systems with high conversion efficiency and low cost is identified as the core challenge.For CO_(2) storage,diverse geological bodies provide vast theoretical capacities on both land and offshore worldwide,but subsidy policies and carbon market regulation are required to offset the limited economic returns of storage technologies.This study highlights several frontier technologies,including low-concentration CO_(2) capture,CO_(2)-enhanced oil recovery(EOR),CO_(2)-based green fuel synthesis,microbial CO_(2) conversion,CO_(2) mineralization and hydrogen production,and CO_(2) cushion gas replacement in underground gas storage(UGS).Through cost-effective innovation,regional pipeline network development,flexible technology integration,coordinated macro-policy regulation,and cross-disciplinary collaboration,CCUS can achieve a transformative scale-up from million-ton and ten-million-ton capacities to the hundred-million-ton level,contributing to the achievement of the carbon neutrality goals of China.展开更多
Sodium glycinate absorption and ethylene carbonate synthesis from a mixture gas of ethylene oxide and carbon dioxide are evaluated as carbon dioxide capture and utilization system for gas engine flue gas. The energy r...Sodium glycinate absorption and ethylene carbonate synthesis from a mixture gas of ethylene oxide and carbon dioxide are evaluated as carbon dioxide capture and utilization system for gas engine flue gas. The energy requirement for CO2 capture is estimated at 3.3 GJ/tonne CO2. The ethylene carbonate synthesis utilizes more than 90% of the captured CO2 and supply 2.5 GJ/tonne CO2 of thermal energy, which is 76% of the energy requirement for CO2 capture. The thermal integration of the sodium glycinate absorption and the ethylene carbonate synthesis reduces the energy requirement for CO2 capture from 3.3 GJ/tonne CO2 to 0.8 GJ/tonne CO2. The energy requirement for the CO2 capture is supplied using the steam saturated at 0.78 MPa from the gas engine without its electric power reduction.展开更多
Carbon dioxide capture,EOR-utilization and storage(CCUS-EOR)are the most practical and feasible large-scale carbon reduction technologies,and also the key technologies to greatly improve the recovery of low-permeabili...Carbon dioxide capture,EOR-utilization and storage(CCUS-EOR)are the most practical and feasible large-scale carbon reduction technologies,and also the key technologies to greatly improve the recovery of low-permeability oil fields.This paper sorts out the main course of CCUS-EOR technological development abroad and its industrialization progress.The progress of CCUS-EOR technological research and field tests in China are summarized,the development status,problems and challenges of the entire industry chain of CO_(2) capture,transportation,oil displacement,and storage are analyzed.The results show a huge potential of the large-scale application of CCUS-EOR in China in terms of carbon emission reduction and oil production increase.At present,CCUS-EOR in China is in a critical stage of development,from field pilot tests to industrialization.Aiming at the feature of continental sedimentary oil and gas reservoirs in China,and giving full play to the advantages of the abundant reserves for CO_(2) flooding,huge underground storage space,surface infrastructure,and wide distribution of wellbore injection channels,by cooperating with carbon emission enterprises,critical technological research and demonstration project construction should be accelerated,including the capture of low-concentration CO_(2) at low-cost and on large-scale,supercritical CO_(2) long-distance transportation,greatly enhancing oil recovery and storage rate,and CO_(2) large-scale and safe storage.CCUS-EOR theoretical and technical standard system should be constructed for the whole industrial chain to support and promote the industrial scale application,leading the rapid and profitable development of CCUS-EOR emerging industrial chain with innovation.展开更多
To achieve carbon dioxide(CO_(2))storage through enhanced oil recovery,accurate forecasting of CO_(2) subsurface storage and cumulative oil production is essential.This study develops hybrid predictive models for the ...To achieve carbon dioxide(CO_(2))storage through enhanced oil recovery,accurate forecasting of CO_(2) subsurface storage and cumulative oil production is essential.This study develops hybrid predictive models for the determination of CO_(2) storage mass and cumulative oil production in unconventional reservoirs.It does so with two multi-layer perceptron neural networks(MLPNN)and a least-squares support vector machine(LSSVM),hybridized with grey wolf optimization(GWO)and/or particle swarm optimization(PSO).Large,simulated datasets were divided into training(70%)and testing(30%)groups,with normalization applied to both groups.Mahalanobis distance identifies/eliminates outliers in the training subset only.A non-dominated sorting genetic algorithm(NSGA-II)combined with LSSVM selected seven influential features from the nine available input parameters:reservoir depth,porosity,permeability,thickness,bottom-hole pressure,area,CO_(2) injection rate,residual oil saturation to gas flooding,and residual oil saturation to water flooding.Predictive models were developed and tested,with performance evaluated with an overfitting index(OFI),scoring analysis,and partial dependence plots(PDP),during training and independent testing to enhance model focus and effectiveness.The LSSVM-GWO model generated the lowest root mean square error(RMSE)values(0.4052 MMT for CO_(2) storage and 9.7392 MMbbl for cumulative oil production)in the training group.That trained model also exhibited excellent generalization and minimal overfitting when applied to the testing group(RMSE of 0.6224 MMT for CO_(2) storage and 12.5143 MMbbl for cumulative oil production).PDP analysis revealed that the input features“area”and“porosity”had the most influence on the LSSVM-GWO model's pre-diction performance.This paper presents a new hybrid modeling approach that achieves accurate forecasting of CO_(2) subsurface storage and cumulative oil production.It also establishes a new standard for such forecasting,which can lead to the development of more effective and sustainable solutions for oil recovery.展开更多
The decarbonization of the built environment is a pressing issue to achieve CO_(2)reduction targets in the concrete industry.Carbon mineralization of construction and demolition waste(C&DW)is an attractive pathway...The decarbonization of the built environment is a pressing issue to achieve CO_(2)reduction targets in the concrete industry.Carbon mineralization of construction and demolition waste(C&DW)is an attractive pathway to capture of CO_(2)as stable carbonates which can be re-utilized and upcycled in a circularized fashion through the creation of new building blocks.Material recovery from the C&DW is often performed in hydrometallurgical leaching using acidic media;however,this process is often hindered by solubility issues and passivation.To ensure high recoveries of these elements,ligands can be used to enhance dissolution.Carboxylic acids are used in conventional hydrometallurgical mineral processing,such as leaching,floatation,and solvent extraction,and are desired due to their affordability and stability.In this study,we explore the dissolution of waste cement pastes in acidic conditions under the presence of four carboxylic acid ligands:formate,acetate,glutamate,and citrate.The leaching kinetics are categorized and the pseudo-rate constants are established,demonstrating the advantages of these agents to enhance reaction rates in the general order of citrate⋙formate>acetate>glutamate>control.The characterization of the post-extraction reactor residue(PERR)revealed a significant increase in Si-content.Finally,the leachate was carbonated to produce calcium carbonate,which was characterized for its use based on morphology and size.Glutamate demonstrated distinct advantages compared to other ligands,with a dual function of not only improving leachability of cement but promoting and stabilizing vaterite during crystallization.Overall,this study motivates the use of sustainable ligands to enhance material recovery during the dissolution of alkaline wastes for carbon mineralization.展开更多
A high efficiency sorbent for CO2 capture was developed by loading polyethylenimine （PEI） on mesoporous carbons which possessed well-developed mesoporous structures and large pore volume. The physicochemical propert...A high efficiency sorbent for CO2 capture was developed by loading polyethylenimine （PEI） on mesoporous carbons which possessed well-developed mesoporous structures and large pore volume. The physicochemical properties of the sorbent were characterized by N2 adsorption/desorption, scanning electron microscopy （SEM）, thermal gravimetric analysis （TG） and Fourier transform infrared spectroscopy （FT-IR） techniques followed by testing for CO2 capture. Factors that affected the sorption capacity of the sorbent were studied. The sorbent exhibited extraordinary capture capacity with CO2 concentration ranging from 5% to 80%. The optimal PEI loading was determined to be 65 wt.% with a CO2 sorption capacity of 4.82 mmol-CO2/g-sorbent in 15% CO2/N2 at 75℃, owing to low mass-transfer resistance and a high utilization ratio of the amine compound （63%）. Moisture had a promoting effect on the sorption separation of CO2. In addition, the developed sorbent could be regenerated easily at 100℃, and it exhibited excellent regenerability and stability. These results indicate that this PEI-loaded mesoporous carbon sorbent should have a good potential for CO2 capture in the future.展开更多
The increase of atmospheric carbon dioxide and the global warming due to its greenhouse effect resulted in worldwide concerns. On the other hand, carbon dioxide might be considered as a valuable and renewable carbon s...The increase of atmospheric carbon dioxide and the global warming due to its greenhouse effect resulted in worldwide concerns. On the other hand, carbon dioxide might be considered as a valuable and renewable carbon source. One approach to reduce carbon dioxide emissions could be its capture and recycle via transformation into chemicals using the technologies in C1 chemistry. Despite its great interest, there are difficulties in CO2 separation on the one hand, and thermodynamic stability of carbon dioxide molecule rendering its chemical activity low on the other hand. Carbon dioxide has been already used in petrochemical industries for production of limited chemicals such as urea. The utilization of carbon dioxide does not necessarily involve development of new processes, and in certain processes such as methanol synthesis and methane steam reforming, addition of CO2 into the feed results in its utilization and increases carbon efficiency. In other cases, modifications in catalyst and/or processes, or even new catalysts and processes, are necessary. In either case, catalysis plays a crucial role in carbon dioxide conversion and effective catalysts are required for commercial realization of the related processes. Technologies for CO2 utilization are emerging after many years of research and development efforts.展开更多
In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is maturing.In this review,we summarized the basic reaction theory of CO2,the CO2 conversion,...In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is maturing.In this review,we summarized the basic reaction theory of CO2,the CO2 conversion,and the change of energy-consumption when CO2 was introduced in converter steelmaking process.In the CO2-O2 mixed injection(COMI)process,the CO2 conversion ratio can be obtained as high as 80%or more with a control of the CO2 ratio in mixture gas and the flow rate of CO2,and the energy is saving and even the energy consumption can be reduced by 145.65 MJ/t under certain operations.In addition,a complete route of CO2 disposal technology is proposed combining the comparatively mature technologies of CO2 capture,CO2 compression,and liquid CO2 storage to improve the technology of CO2 utilization.The results are expected to form a large-scale,highly efficient,and valuable method to dispose of CO2.展开更多
An approach to the simultaneous reclamation of carbon and sulfur resources from CO2 and H2S has been proposed and effectively implemented with the aid of catalysts. A brief thermodynamic study reveals the potential of...An approach to the simultaneous reclamation of carbon and sulfur resources from CO2 and H2S has been proposed and effectively implemented with the aid of catalysts. A brief thermodynamic study reveals the potential of direct reduction of CO2 with H2S（15：15 mol% balanced with N2） for selective production of CO and elemental sulfur. The experiments carried out in a fixed-bed flow reactor over the temperature range of 400–800 °C give evidence of the importance of the employment of catalysts. Both the conversions of the reactants and the selectivities of the target products can be substantially promoted over most catalysts studied. Nevertheless, little difference appears among their catalytic performance. The results also prove that the presence of CO2 can remarkably enhance H2S conversion and the sulfur yield in comparison with H2S direct decomposition. A longtime reaction test on Mg O catalyst manifests its superior durability at high temperature（700 °C） and huge gas hourly space velocity（100,000 h-1）. Free radicals initiated by catalysts are supposed to dominate the reactions between CO2 and H2S.展开更多
The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to b...The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo(GCMC)simulations were then carried out to investigate the single and binary component adsorption of CO_2 and CH_4with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO_2 adsorption is greater than that of CH_4 adsorption. CO_2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH_4, which can account for the larger adsorption capacity of CO_2 in the bituminous coal model. In the case of binary adsorption of CO_2 and CH_4mixtures, CO_2 exhibits the preferential adsorption compared with CH_4 under the studied conditions. The adsorption selectivity of CO_2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO_2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO_2 decreases gradually with the increase of the bulk CO_2 mole fraction and the depth of CO_2 injection site.展开更多
The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main...The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main source of carbon emissions,the consumption of fossil energy is the most profoundly affected by carbon neutrality.This work presents an analysis of how China can achieve its goal of carbon neutrality based on its status of fossil energy utilization.The significance of transforming fossils from energy to resource utilization in the future is addressed,while the development direction and key technologies are discussed.展开更多
Carbon capture,utilization,and storage(CCUS)is widely recognized as a technological system capable of achieving large-scale carbon dioxide emission reductions.However,its high costs and potential risks have limited it...Carbon capture,utilization,and storage(CCUS)is widely recognized as a technological system capable of achieving large-scale carbon dioxide emission reductions.However,its high costs and potential risks have limited its large-scale implementation.This study focuses on enhancing the economic viability of traditional CCUS by proposing a novel technological concept and system that integrates CCUS with water extraction,geothermal energy harvesting,hydrogen production,and energy storage.The system comprises three interconnected modules:(1)upstream CO_(2)-enhanced water recovery(CO_(2)-EWR),(2)midstream green hydrogen synthesis,and(3)downstream energy utilization.Through detailed explanations of the fundamental concept and related technological systems,its feasibility is demonstrated.Preliminary estimates indicate that under current conditions,the system lacks economic advantages.However,significant reductions in hydrogen production costs could enable the system to yield a profit of nearly 1000 Chinese Yuan(approximately 145 US dollars)per ton of CO_(2)in the future.Following an in-depth investigation,priority implementation in China's Tarim Basin and Ordos Basin is recommended.This technological system could significantly extend the industrial chain of traditional CCUS projects,promising additional social and ecnomic benefits.Furthermore,the involved gas-water displacement technology can help manage formation pressure and reduce leakage risks in large-scale carbon storage projects.展开更多
CO_(2)-enhanced oil recovery(CO_(2)-EOR)is an economically viable carbon capture,utilization,and storage(CCUS)technique that is widely practiced and greatly contributes to the achievement of carbon-neutral cities.Howe...CO_(2)-enhanced oil recovery(CO_(2)-EOR)is an economically viable carbon capture,utilization,and storage(CCUS)technique that is widely practiced and greatly contributes to the achievement of carbon-neutral cities.However,studies on CO_(2)-EOR source-sink matching involving different emission sources,different carbon capture rates,and stepwise CO_(2)pipeline construction are scarce.Considering four types of carbon sources,including coal-fired power,iron and steel,cement,and chemical plants,with different CO_(2)capture rates(85%,90%,95%,and 100%,respectively),and using a five-phased construction plan with a 25-year build-up period,we developed a method for quantifying carbon emissions from different sources,calculating the effective storage of carbon in CO_(2)-EOR and optimizing CO_(2)-EOR source-sink matching to reduce project costs.Using the Subei Basin in the Jiangsu Province,China,as a case study,we calculated the theoretical CO_(2)-EOR storage to be 1.7408×10^(8)t and the effective CO_(2)-EOR storage to be 0.435×10^(8)t.We analyzed the completion rate of transportation pipelines,the number of connected carbon sources,and the mass of CO_(2)stored,as well as the cost-effectiveness and sensitivity.Implementation of CO_(2)-EOR effectively reduced the total cost of source-sink matching in the five-stage 25-year construction approach.The reduction of CO_(2)capture rates had no effect on the value of oil repelling.The capture cost significantly affected the total cost of source-sink matching,and the impacts of the carbon sources on the total cost were in the order coal-fired power>iron and steel>cement>chemical plants.This study provides an innovative tool for evaluating the CO_(2)storage potential of CO_(2)-EOR and provides an important framework for implementing CO_(2)-EOR and planning CCUS projects in the Subei Basin and similar regions.展开更多
Synthesis of cyclic carbonates from carbon dioxide(CO_(2))and epoxides is an effective pathway for the CO_(2) utilization.Although various metal catalysts have been reported,it is highly desirable to develop a method ...Synthesis of cyclic carbonates from carbon dioxide(CO_(2))and epoxides is an effective pathway for the CO_(2) utilization.Although various metal catalysts have been reported,it is highly desirable to develop a method for the reuse or recycling of catalysts.Herein,an N-heterocyclic carbene-pyridine molybdenum complex supported over SBA-15(Mo@SBA-15)was used as an efficient and recyclable catalyst for converting CO_(2) and epoxides into cyclic carbonates.Mo@SBA-15 in combination with tetra-butylammonium bromide(TBAB)shows high catalytic activity in the synthesis of cyclic carbonates under 100℃and 1 MPa CO_(2) pressure.In addition,Mo@SBA-15 was reused seven times without any significant activity loss.展开更多
In recent years, China’s industrialization and urbanization have deepened, and the economy has grown considerably. But at the same time, they have also brought about many environmental problems. As a pillar of the na...In recent years, China’s industrialization and urbanization have deepened, and the economy has grown considerably. But at the same time, they have also brought about many environmental problems. As a pillar of the national economy, the iron and steel(IS) industry is one of the most emitting and energy-consuming sub-sectors of the industrial sector. It is also one of the industries with the most severe overcapacity problem in China. In this paper, we explore the impact of capacity utilization on carbon dioxide emission based on panel data of China’s iron and steel industry from 2005 to 2014. We also tested the heterogeneity in different regions and different sub-samples. Results show that capacity utilization and carbon dioxide emission are positively correlated. However, the impact of capacity utilization on carbon dioxide emission differs when considering regional heterogeneity. Results in all three regions show a positive relationship between capacity utilization and carbon dioxide emission,but the impact intensity is strongest in the western region, followed by the eastern and central regions.Moreover, capacity utilization impacts carbon dioxide emission by influencing firm numbers in the iron and steel industry and energy consumption. Further analysis shows that there exists a threshold effect in different stages of energy consumption and energy structure. Finally, some findings and practical policy recommendations are provided.展开更多
CO_(2) capture is a process with a high energy consumption,and its large-scale implementation should be based on comprehensive analysis of its impact on the energy,economy,and environment.The process of injecting CO_(...CO_(2) capture is a process with a high energy consumption,and its large-scale implementation should be based on comprehensive analysis of its impact on the energy,economy,and environment.The process of injecting CO_(2) into existing oil fields is a well-known enhanced oil recovery(CO_(2)-EOR)technique.Using CO_(2) as a working fluid to recover oil can compensate for the energy consumption of the capture and transport processes,increasing the feasibility of CO_(2) capture while achieving carbon sequestration.In this study,a full-chain CO_(2) capture,utilization,and storage(CCUS)system based on the post-combustion capture method is deconstructed and coupled.A full-chain energy consumption calculation software is developed,and optimization analysis of the energy consumption system is conducted.The energy budget of the oil displacement utilization is deconstructed,and the advantages of the water alternating gas(WAG)method are clarified from an energy budget point of view.The analysis reveals that the benefits of CO_(2)-EOR are far greater than the energy consumption of other CCUS processes,and CCUS-EOR is a CO_(2) utilization method with positive energy benefits.Based on the simulation of the effects of N_(2) and CH_(4) on the recovery factor,a multi-well combined injection-production method is proposed,and the reasons for increasing profit are analyzed.展开更多
基金support from the National Natural Science Fund (50904073)the CNPC Science and Technology Innovation Fund (2008D-5006-02-06)
文摘Supercritical carbon dioxide （scCO2） microemulsion was formed by supercritical CO2, H20, sodium bis（2-ethylhexyl） sulfosuccinate （AOT, surfactant） and C2HsOH （co-surfactant） under pressures higher than 8 MPa at 45 ℃. The fundamental characteristics of the scCO2 microemulsion and the minimum miscibility pressure （MMP） with Daqing oil were investigated with a high-pressure falling sphere viscometer, a high-pressure interfacial tension meter, a PVT cell and a slim tube test. The mechanism of the scCO2 microemulsion for enhancing oil recovery is discussed. The results showed that the viscosity and density of the scCO2 microemulsion were higher than those of the scCO2 fluid at the same pressure and temperature. The results of interfacial tension and slim tube tests indicated that the MMP of the scCO2 microemulsion and crude oil was lower than that of the scCO2 and crude oil at 45 ℃. It is the combined action of viscosity, density and MMP which made the oil recovery efficiency of the scCO2 microemulsion higher than that of the scCO2 fluid.
文摘Climate researchers have observed that the carbon dioxide （CO2） concentration in the atmosphere have been growing significantly over the past century. CO2 from energy represents about 75% of the greenhouse gas （GHG） emissions for Annex B （Developed） countries, and over 60% of global emissions. Because of impermeable cap rocks hydrocarbon reservoirs are able to sequester CO〉 In addition, due to high-demand for oil worldwide, injection of CO2 is a useful way to enhance oil production. Hence, applying an efficient method to co-optimize CO2 storage and oil production is vital. Lack of suitable optimization techniques in the past led most multi-objective optimization problems to be tackled in the same way as a single objective optimization issue. However, there are some basic differences between the multi and single objective optimization methods. In this study, by using a non- dominated sorting genetic algorithm （NSGA-II） for an oil reservoir, some appropriate scenarios are proposed based on simultaneous gas storage and enhanced oil recovery optimization. The advantages of this method allow us to amend production scenarios after implementing the optimization process, by regarding the variation of economic parameters such as oil price and CO2 tax. This leads to reduced risks and time duration of making new decisions based on upcoming situations.
文摘The development and deployment of Carbon dioxide Capture and Storage （CCS） technology is a cornerstone of the Norwegian government＇s climate strategy. A number of projects are currently evaluated/planned along the Norwegian West Coast, one at Tjeldbergodden. COe from this project will be utilized in part for enhanced oil recovery in the Halten oil field, in the Norwegian Sea. We study a potential design of such a system. A combined cycle power plant with a gross power output of 832 MW is combined with CO2 capture plant based on a post-combustion capture using amines as a solvent. The captured CO2 is used for enhanced oil recovery （EOR）. We employ a hybrid life-cycle assessment （LCA） method to assess the environmental impacts of the system. The study focuses on the modifications and operations of the platform during EOR. We allocate the impacts connected to the capture of CO2 to electricity production, and the impacts connected to the transport and storage of CO2 to the oil produced. Our study shows a substantial reduction of the greenhouse gas emissions from power production by 80% to 75 g·（kW·h）^-1. It also indicates a reduction of the emissions associated with oil production per unit oil produced, mostly due to the increased oil production. Reductions are especially significant if the additional power demand due to EOR leads to power supply from the land.
文摘In order to enhance coalbed methane recovery, taking a self-developed largecalesimulation system for the platform, a modeling experiment of driving CH_4 by CO_2 gasinjection was studied.The results of experiment indicates that there is a significant lag effectof adsorption and desorption on gas, the gas pressure is changed more rapidly in theprocess of carbon dioxide adsorption of coal than methane adsorption of coal; After theinjection of carbon dioxide, compare with methane single desorption.In an early stage,speed and amount of methane single desorption are greater than the speed and amountof displacement desorption, the speed and amount of displacement desorption becamegreater.In the process of replacement, CH_4 concentration constantly declined, while CO_2concentration constantly rose.In the process of CO_2 gas injection, the temperature of coalhave been significantly increased, it is more beneficial to make CH_4 gas molecules becomefree from the adsorbed state when temperature is increased.Under the pressurestep-down at the same rate, using the method of CO_2 driving CH_4, compared with themethod of conventional pressure step-down, the desorption rate of CH_4 in coal can beraised about 2.13 times, at the same time, a lot of greenhouse gas CO_2 will also be buriedin the ground, there is a very significant environmental benefit.
基金Supported by the Major Project of the National Social Science Fund of China(24&ZD106)National Science and Technology Major Project on New Oil and Gas Exploration and Development(205ZD1406807)Soft Science Research Project of CNPC(20250110-4).
文摘This study reviews the recent progress and trends of carbon capture,utilization and storage(CCUS)technologies,with a particular focus on related policy orientations,technological status,and representative projects across North America,Europe,the Middle East,and China.The technical connotations of CCUS are elucidated,and the existing issues and challenges are identified from the perspectives of technology,economics,safety and system integration.The CO_(2) capture technologies are relatively mature;the emergence of novel processes such as direct air capture(DAC)and advanced materials such as metal-organic frameworks(MOFs)offer new choices for efficient capture,but issues related to high energy consumption and operational costs remain unresolved.The CO_(2) geological utilization has developed earlier,where breakthroughs rely on effective source matching,enhanced miscibility and increased swept volume.The CO_(2) chemical utilization exhibits broad market potential for producing high value-added products,and the development of catalytic systems with high conversion efficiency and low cost is identified as the core challenge.For CO_(2) storage,diverse geological bodies provide vast theoretical capacities on both land and offshore worldwide,but subsidy policies and carbon market regulation are required to offset the limited economic returns of storage technologies.This study highlights several frontier technologies,including low-concentration CO_(2) capture,CO_(2)-enhanced oil recovery(EOR),CO_(2)-based green fuel synthesis,microbial CO_(2) conversion,CO_(2) mineralization and hydrogen production,and CO_(2) cushion gas replacement in underground gas storage(UGS).Through cost-effective innovation,regional pipeline network development,flexible technology integration,coordinated macro-policy regulation,and cross-disciplinary collaboration,CCUS can achieve a transformative scale-up from million-ton and ten-million-ton capacities to the hundred-million-ton level,contributing to the achievement of the carbon neutrality goals of China.
文摘Sodium glycinate absorption and ethylene carbonate synthesis from a mixture gas of ethylene oxide and carbon dioxide are evaluated as carbon dioxide capture and utilization system for gas engine flue gas. The energy requirement for CO2 capture is estimated at 3.3 GJ/tonne CO2. The ethylene carbonate synthesis utilizes more than 90% of the captured CO2 and supply 2.5 GJ/tonne CO2 of thermal energy, which is 76% of the energy requirement for CO2 capture. The thermal integration of the sodium glycinate absorption and the ethylene carbonate synthesis reduces the energy requirement for CO2 capture from 3.3 GJ/tonne CO2 to 0.8 GJ/tonne CO2. The energy requirement for the CO2 capture is supplied using the steam saturated at 0.78 MPa from the gas engine without its electric power reduction.
基金Supported by the Major Science and Technology Project of PetroChina(2021ZZ01).
文摘Carbon dioxide capture,EOR-utilization and storage(CCUS-EOR)are the most practical and feasible large-scale carbon reduction technologies,and also the key technologies to greatly improve the recovery of low-permeability oil fields.This paper sorts out the main course of CCUS-EOR technological development abroad and its industrialization progress.The progress of CCUS-EOR technological research and field tests in China are summarized,the development status,problems and challenges of the entire industry chain of CO_(2) capture,transportation,oil displacement,and storage are analyzed.The results show a huge potential of the large-scale application of CCUS-EOR in China in terms of carbon emission reduction and oil production increase.At present,CCUS-EOR in China is in a critical stage of development,from field pilot tests to industrialization.Aiming at the feature of continental sedimentary oil and gas reservoirs in China,and giving full play to the advantages of the abundant reserves for CO_(2) flooding,huge underground storage space,surface infrastructure,and wide distribution of wellbore injection channels,by cooperating with carbon emission enterprises,critical technological research and demonstration project construction should be accelerated,including the capture of low-concentration CO_(2) at low-cost and on large-scale,supercritical CO_(2) long-distance transportation,greatly enhancing oil recovery and storage rate,and CO_(2) large-scale and safe storage.CCUS-EOR theoretical and technical standard system should be constructed for the whole industrial chain to support and promote the industrial scale application,leading the rapid and profitable development of CCUS-EOR emerging industrial chain with innovation.
文摘To achieve carbon dioxide(CO_(2))storage through enhanced oil recovery,accurate forecasting of CO_(2) subsurface storage and cumulative oil production is essential.This study develops hybrid predictive models for the determination of CO_(2) storage mass and cumulative oil production in unconventional reservoirs.It does so with two multi-layer perceptron neural networks(MLPNN)and a least-squares support vector machine(LSSVM),hybridized with grey wolf optimization(GWO)and/or particle swarm optimization(PSO).Large,simulated datasets were divided into training(70%)and testing(30%)groups,with normalization applied to both groups.Mahalanobis distance identifies/eliminates outliers in the training subset only.A non-dominated sorting genetic algorithm(NSGA-II)combined with LSSVM selected seven influential features from the nine available input parameters:reservoir depth,porosity,permeability,thickness,bottom-hole pressure,area,CO_(2) injection rate,residual oil saturation to gas flooding,and residual oil saturation to water flooding.Predictive models were developed and tested,with performance evaluated with an overfitting index(OFI),scoring analysis,and partial dependence plots(PDP),during training and independent testing to enhance model focus and effectiveness.The LSSVM-GWO model generated the lowest root mean square error(RMSE)values(0.4052 MMT for CO_(2) storage and 9.7392 MMbbl for cumulative oil production)in the training group.That trained model also exhibited excellent generalization and minimal overfitting when applied to the testing group(RMSE of 0.6224 MMT for CO_(2) storage and 12.5143 MMbbl for cumulative oil production).PDP analysis revealed that the input features“area”and“porosity”had the most influence on the LSSVM-GWO model's pre-diction performance.This paper presents a new hybrid modeling approach that achieves accurate forecasting of CO_(2) subsurface storage and cumulative oil production.It also establishes a new standard for such forecasting,which can lead to the development of more effective and sustainable solutions for oil recovery.
基金supported by the New York State Energy Research&Development Authority(NYSERDA,Albany,New York)Agreement Number:0000185059the Lenfest Center for Sustainable Energy(Columbia University,New York,New York).
文摘The decarbonization of the built environment is a pressing issue to achieve CO_(2)reduction targets in the concrete industry.Carbon mineralization of construction and demolition waste(C&DW)is an attractive pathway to capture of CO_(2)as stable carbonates which can be re-utilized and upcycled in a circularized fashion through the creation of new building blocks.Material recovery from the C&DW is often performed in hydrometallurgical leaching using acidic media;however,this process is often hindered by solubility issues and passivation.To ensure high recoveries of these elements,ligands can be used to enhance dissolution.Carboxylic acids are used in conventional hydrometallurgical mineral processing,such as leaching,floatation,and solvent extraction,and are desired due to their affordability and stability.In this study,we explore the dissolution of waste cement pastes in acidic conditions under the presence of four carboxylic acid ligands:formate,acetate,glutamate,and citrate.The leaching kinetics are categorized and the pseudo-rate constants are established,demonstrating the advantages of these agents to enhance reaction rates in the general order of citrate⋙formate>acetate>glutamate>control.The characterization of the post-extraction reactor residue(PERR)revealed a significant increase in Si-content.Finally,the leachate was carbonated to produce calcium carbonate,which was characterized for its use based on morphology and size.Glutamate demonstrated distinct advantages compared to other ligands,with a dual function of not only improving leachability of cement but promoting and stabilizing vaterite during crystallization.Overall,this study motivates the use of sustainable ligands to enhance material recovery during the dissolution of alkaline wastes for carbon mineralization.
基金supported by the National Natural Science Foundation of China (No. 50730003)the Program for New Century Excellent Talents in University (No. NCET-07-0285)the Fundamental Research Funds for the Central Universities
文摘A high efficiency sorbent for CO2 capture was developed by loading polyethylenimine （PEI） on mesoporous carbons which possessed well-developed mesoporous structures and large pore volume. The physicochemical properties of the sorbent were characterized by N2 adsorption/desorption, scanning electron microscopy （SEM）, thermal gravimetric analysis （TG） and Fourier transform infrared spectroscopy （FT-IR） techniques followed by testing for CO2 capture. Factors that affected the sorption capacity of the sorbent were studied. The sorbent exhibited extraordinary capture capacity with CO2 concentration ranging from 5% to 80%. The optimal PEI loading was determined to be 65 wt.% with a CO2 sorption capacity of 4.82 mmol-CO2/g-sorbent in 15% CO2/N2 at 75℃, owing to low mass-transfer resistance and a high utilization ratio of the amine compound （63%）. Moisture had a promoting effect on the sorption separation of CO2. In addition, the developed sorbent could be regenerated easily at 100℃, and it exhibited excellent regenerability and stability. These results indicate that this PEI-loaded mesoporous carbon sorbent should have a good potential for CO2 capture in the future.
文摘The increase of atmospheric carbon dioxide and the global warming due to its greenhouse effect resulted in worldwide concerns. On the other hand, carbon dioxide might be considered as a valuable and renewable carbon source. One approach to reduce carbon dioxide emissions could be its capture and recycle via transformation into chemicals using the technologies in C1 chemistry. Despite its great interest, there are difficulties in CO2 separation on the one hand, and thermodynamic stability of carbon dioxide molecule rendering its chemical activity low on the other hand. Carbon dioxide has been already used in petrochemical industries for production of limited chemicals such as urea. The utilization of carbon dioxide does not necessarily involve development of new processes, and in certain processes such as methanol synthesis and methane steam reforming, addition of CO2 into the feed results in its utilization and increases carbon efficiency. In other cases, modifications in catalyst and/or processes, or even new catalysts and processes, are necessary. In either case, catalysis plays a crucial role in carbon dioxide conversion and effective catalysts are required for commercial realization of the related processes. Technologies for CO2 utilization are emerging after many years of research and development efforts.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51334001,51674021,51574021,and 51734003).
文摘In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is maturing.In this review,we summarized the basic reaction theory of CO2,the CO2 conversion,and the change of energy-consumption when CO2 was introduced in converter steelmaking process.In the CO2-O2 mixed injection(COMI)process,the CO2 conversion ratio can be obtained as high as 80%or more with a control of the CO2 ratio in mixture gas and the flow rate of CO2,and the energy is saving and even the energy consumption can be reduced by 145.65 MJ/t under certain operations.In addition,a complete route of CO2 disposal technology is proposed combining the comparatively mature technologies of CO2 capture,CO2 compression,and liquid CO2 storage to improve the technology of CO2 utilization.The results are expected to form a large-scale,highly efficient,and valuable method to dispose of CO2.
基金financial supports from the Fushun Research Institute of Petroleum&Petrochemicals(no.KG12009)the Natural Science Foundation of China(no.21276077)the Fundamental Research Funds for Central Universities(no.WG1213011)
文摘An approach to the simultaneous reclamation of carbon and sulfur resources from CO2 and H2S has been proposed and effectively implemented with the aid of catalysts. A brief thermodynamic study reveals the potential of direct reduction of CO2 with H2S（15：15 mol% balanced with N2） for selective production of CO and elemental sulfur. The experiments carried out in a fixed-bed flow reactor over the temperature range of 400–800 °C give evidence of the importance of the employment of catalysts. Both the conversions of the reactants and the selectivities of the target products can be substantially promoted over most catalysts studied. Nevertheless, little difference appears among their catalytic performance. The results also prove that the presence of CO2 can remarkably enhance H2S conversion and the sulfur yield in comparison with H2S direct decomposition. A longtime reaction test on Mg O catalyst manifests its superior durability at high temperature（700 °C） and huge gas hourly space velocity（100,000 h-1）. Free radicals initiated by catalysts are supposed to dominate the reactions between CO2 and H2S.
基金Supported by the CNPC Huabei Oilfield Science and Technology Development Project(HBYT-CYY-2014-JS-378,HBYT-CYY-2015-JS-47)
文摘The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo(GCMC)simulations were then carried out to investigate the single and binary component adsorption of CO_2 and CH_4with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO_2 adsorption is greater than that of CH_4 adsorption. CO_2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH_4, which can account for the larger adsorption capacity of CO_2 in the bituminous coal model. In the case of binary adsorption of CO_2 and CH_4mixtures, CO_2 exhibits the preferential adsorption compared with CH_4 under the studied conditions. The adsorption selectivity of CO_2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO_2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO_2 decreases gradually with the increase of the bulk CO_2 mole fraction and the depth of CO_2 injection site.
文摘The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main source of carbon emissions,the consumption of fossil energy is the most profoundly affected by carbon neutrality.This work presents an analysis of how China can achieve its goal of carbon neutrality based on its status of fossil energy utilization.The significance of transforming fossils from energy to resource utilization in the future is addressed,while the development direction and key technologies are discussed.
基金Joint Funds of the National Natural Science Foundation of China,Grant/Award Number:U2344226。
文摘Carbon capture,utilization,and storage(CCUS)is widely recognized as a technological system capable of achieving large-scale carbon dioxide emission reductions.However,its high costs and potential risks have limited its large-scale implementation.This study focuses on enhancing the economic viability of traditional CCUS by proposing a novel technological concept and system that integrates CCUS with water extraction,geothermal energy harvesting,hydrogen production,and energy storage.The system comprises three interconnected modules:(1)upstream CO_(2)-enhanced water recovery(CO_(2)-EWR),(2)midstream green hydrogen synthesis,and(3)downstream energy utilization.Through detailed explanations of the fundamental concept and related technological systems,its feasibility is demonstrated.Preliminary estimates indicate that under current conditions,the system lacks economic advantages.However,significant reductions in hydrogen production costs could enable the system to yield a profit of nearly 1000 Chinese Yuan(approximately 145 US dollars)per ton of CO_(2)in the future.Following an in-depth investigation,priority implementation in China's Tarim Basin and Ordos Basin is recommended.This technological system could significantly extend the industrial chain of traditional CCUS projects,promising additional social and ecnomic benefits.Furthermore,the involved gas-water displacement technology can help manage formation pressure and reduce leakage risks in large-scale carbon storage projects.
基金Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20231488National Natural Science Foundation of China,Grant/Award Numbers:52378083,52078481。
文摘CO_(2)-enhanced oil recovery(CO_(2)-EOR)is an economically viable carbon capture,utilization,and storage(CCUS)technique that is widely practiced and greatly contributes to the achievement of carbon-neutral cities.However,studies on CO_(2)-EOR source-sink matching involving different emission sources,different carbon capture rates,and stepwise CO_(2)pipeline construction are scarce.Considering four types of carbon sources,including coal-fired power,iron and steel,cement,and chemical plants,with different CO_(2)capture rates(85%,90%,95%,and 100%,respectively),and using a five-phased construction plan with a 25-year build-up period,we developed a method for quantifying carbon emissions from different sources,calculating the effective storage of carbon in CO_(2)-EOR and optimizing CO_(2)-EOR source-sink matching to reduce project costs.Using the Subei Basin in the Jiangsu Province,China,as a case study,we calculated the theoretical CO_(2)-EOR storage to be 1.7408×10^(8)t and the effective CO_(2)-EOR storage to be 0.435×10^(8)t.We analyzed the completion rate of transportation pipelines,the number of connected carbon sources,and the mass of CO_(2)stored,as well as the cost-effectiveness and sensitivity.Implementation of CO_(2)-EOR effectively reduced the total cost of source-sink matching in the five-stage 25-year construction approach.The reduction of CO_(2)capture rates had no effect on the value of oil repelling.The capture cost significantly affected the total cost of source-sink matching,and the impacts of the carbon sources on the total cost were in the order coal-fired power>iron and steel>cement>chemical plants.This study provides an innovative tool for evaluating the CO_(2)storage potential of CO_(2)-EOR and provides an important framework for implementing CO_(2)-EOR and planning CCUS projects in the Subei Basin and similar regions.
文摘Synthesis of cyclic carbonates from carbon dioxide(CO_(2))and epoxides is an effective pathway for the CO_(2) utilization.Although various metal catalysts have been reported,it is highly desirable to develop a method for the reuse or recycling of catalysts.Herein,an N-heterocyclic carbene-pyridine molybdenum complex supported over SBA-15(Mo@SBA-15)was used as an efficient and recyclable catalyst for converting CO_(2) and epoxides into cyclic carbonates.Mo@SBA-15 in combination with tetra-butylammonium bromide(TBAB)shows high catalytic activity in the synthesis of cyclic carbonates under 100℃and 1 MPa CO_(2) pressure.In addition,Mo@SBA-15 was reused seven times without any significant activity loss.
基金Supported by National Natural Science Foundation of China (72071067, 71601064, 71801067)。
文摘In recent years, China’s industrialization and urbanization have deepened, and the economy has grown considerably. But at the same time, they have also brought about many environmental problems. As a pillar of the national economy, the iron and steel(IS) industry is one of the most emitting and energy-consuming sub-sectors of the industrial sector. It is also one of the industries with the most severe overcapacity problem in China. In this paper, we explore the impact of capacity utilization on carbon dioxide emission based on panel data of China’s iron and steel industry from 2005 to 2014. We also tested the heterogeneity in different regions and different sub-samples. Results show that capacity utilization and carbon dioxide emission are positively correlated. However, the impact of capacity utilization on carbon dioxide emission differs when considering regional heterogeneity. Results in all three regions show a positive relationship between capacity utilization and carbon dioxide emission,but the impact intensity is strongest in the western region, followed by the eastern and central regions.Moreover, capacity utilization impacts carbon dioxide emission by influencing firm numbers in the iron and steel industry and energy consumption. Further analysis shows that there exists a threshold effect in different stages of energy consumption and energy structure. Finally, some findings and practical policy recommendations are provided.
基金supported by the National Key Research and Development Program of China(No.2016YFB0600805).
文摘CO_(2) capture is a process with a high energy consumption,and its large-scale implementation should be based on comprehensive analysis of its impact on the energy,economy,and environment.The process of injecting CO_(2) into existing oil fields is a well-known enhanced oil recovery(CO_(2)-EOR)technique.Using CO_(2) as a working fluid to recover oil can compensate for the energy consumption of the capture and transport processes,increasing the feasibility of CO_(2) capture while achieving carbon sequestration.In this study,a full-chain CO_(2) capture,utilization,and storage(CCUS)system based on the post-combustion capture method is deconstructed and coupled.A full-chain energy consumption calculation software is developed,and optimization analysis of the energy consumption system is conducted.The energy budget of the oil displacement utilization is deconstructed,and the advantages of the water alternating gas(WAG)method are clarified from an energy budget point of view.The analysis reveals that the benefits of CO_(2)-EOR are far greater than the energy consumption of other CCUS processes,and CCUS-EOR is a CO_(2) utilization method with positive energy benefits.Based on the simulation of the effects of N_(2) and CH_(4) on the recovery factor,a multi-well combined injection-production method is proposed,and the reasons for increasing profit are analyzed.
