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Technologies and practice of CO2 flooding and sequestration in China 被引量:8
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作者 HU Yongle HAO Mingqiang +2 位作者 CHEN Guoli SUN Ruiyan LI Shi 《Petroleum Exploration and Development》 2019年第4期753-766,共14页
The latest advancement of CO2 flooding and sequestration theory and technology in China is systematically described, and the future development direction is put forward. Based on the geological characteristics of cont... The latest advancement of CO2 flooding and sequestration theory and technology in China is systematically described, and the future development direction is put forward. Based on the geological characteristics of continental reservoirs, five theories and key technologies have been developed:(1) Enriched the understandings about the mass transfer characteristics of components between CO2 and crude oil in continental reservoirs, micro-flooding mechanism and sequestration mechanism of different geological bodies.(2) Established the design method of reservoir engineering parameters, injection-production control technology and development effect evaluation technology of CO2 flooding, etc.(3) Developed a series of production engineering technologies such as separated layer CO2 injection technology, high efficiency lifting technology, on-line wellbore corrosion monitoring and protection technology.(4) Innovated a series of surface engineering technology including CO2 capture technology, pipeline CO2 transportation, CO2 surface injection, and production gas circulation injection, etc.(5) Formed a series of supporting technologies including monitoring, and safety and environmental protection evaluation of CO2 flooding reservoir. On this basis, the technological development directions in the future have been put forward:(1) Breakthrough in low-cost CO2 capture technology to provide cheap CO2 gas source;(2) Improve the miscibility technology between CO2 and crude oil to enhance oil displacement efficiency;(3) Improve CO2 sweeping volume;(4) Develop more effective lifting tools and technologies;(5) Strengthen the research of basic theory and key technology of CO2 storage monitoring. CO2 flooding and sequestration in the Jilin Oilfield shows that this technology has broad application prospects in China. 展开更多
关键词 CONTINENTAL RESERVOIRS co2 FLOODING and SEQUESTRATION enhanced oil recovery RESERVOIR ENGINEERING injection and production ENGINEERING surface ENGINEERING development direction
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Robust Resource Management Control for CO2 Emission and Reduction of Greenhouse Effect: Stochastic Game Approach
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作者 Bor-Sen Chen Ying-Po Lin 《Journal of Environmental Protection》 2011年第9期1172-1191,共20页
With the increasingly severe global warming, investments in clean technology, reforestation and political action have been studied to reduce CO2 emission. In this study, a nonlinear stochastic model is proposed to des... With the increasingly severe global warming, investments in clean technology, reforestation and political action have been studied to reduce CO2 emission. In this study, a nonlinear stochastic model is proposed to describe the dynamics of CO2 emission with control inputs: clean technology, reforestation and carbon tax, under stochastic uncertainties. For the efficient resources management, a robust tracking control is designed to force resources tracking a desired reference output. The worst-case effect of stochastic parametric fluctuations, external disturbances and uncertain initial conditions on the tracking performance is considered and minimized from the dynamic game theory perspective. This stochastic game problem, in which one player (stochastic uncertainty) maximizes the tracking error and another player (control input) minimizes the tracking error, could be equivalent to a robust minimax tracking problem. To avoid solving the HJI, a fuzzy model is proposed to approximate the nonlinear CO2 emission model. Then the nonlinear stochastic game problem could be easily solved by fuzzy stochastic game approach via LMI technique. 展开更多
关键词 co2 Emission System Dynamic GAME Theory GREENHOUSE Effect LMI RESOURCE Management CONTROL ROBUST Tracking CONTROL T-S Fuzzy Model
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Influences of the NAO on the North Atlantic CO2 Fluxes in Winter and Summer on the Interannual Scale
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作者 Yujie JING Yangchun LI +1 位作者 Yongfu XU Guangzhou FAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第11期1288-1298,共11页
The differences in the influences of the North Atlantic Oscillation (NAO) on the air–sea CO2 fluxes (fCO2) in the North Atlantic (NA) between different seasons and between different regions are rarely fully investiga... The differences in the influences of the North Atlantic Oscillation (NAO) on the air–sea CO2 fluxes (fCO2) in the North Atlantic (NA) between different seasons and between different regions are rarely fully investigated. We used observation-based data of fCO2, surface-ocean CO2 partial pressure (pCO2sea), wind speed and sea surface temperature (SST) to analyze the relationship between the NAO and fCO2 of the subtropical and subpolar NA in winter and summer on the interannual time scale. Based on power spectrum estimation, there are significant interannual signs with a 2–6 year cycle in the NAO indexes and area-averaged fCO2 anomalies in winter and summer from 1980 to 2015. Regression analysis with the 2–6 year filtered data shows that on the interannual scale the response of the fCO2 anomalies to the NAO has an obvious meridional wave-train-like pattern in winter, but a zonal distribution in summer. This seasonal difference is because in winter the fCO2 anomalies are mainly controlled by the NAO-driven wind speed anomalies, which have a meridional distribution pattern, while in summer they are dominated by the NAO-driven SST anomalies, which show distinct zonal difference in the subtropical NA. In addition, in the same season, there are different factors controlling the variation of pCO2sea in different regions. In summer, SST is important to the interannual variation of pCO2sea in the subtropical NA, while some biogeochemical variables probably control the pCO2sea variation in the subpolar NA. 展开更多
关键词 AIR-SEA co2 flux North ATLANTIC Oscillation INTERANNUAL time SCALE wind speed surface-ocean co2 partial pressure
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Measurement of radial temperature distributions of the blown CO2 arcs under different conditions
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作者 Yang LI Shaodi FAN +4 位作者 Yi WU Hao SUN Haodong CHANG Luqi LIANG Weiping GUAN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第12期50-56,共7页
In this paper, the radial temperature distributions of the blown CO2 arcs in a model gas circuit breaker were investigated by optical emission spectroscopy methods. The CO2 flows with different flow rates(50, 100 and ... In this paper, the radial temperature distributions of the blown CO2 arcs in a model gas circuit breaker were investigated by optical emission spectroscopy methods. The CO2 flows with different flow rates(50, 100 and 150 1 min^-1) were created to axially blow the arcs burning in a polymethyl methacrylate(PMMA) nozzle. Discharges with different arc currents(200 and 400A) were conducted in the experiment. The absolute intensity method was applied for a carbon ionic line of 657.8 nm to obtain the radial temperature profiles of the arc columns at a cross-section 1 mm above the nozzle. The calibration for the intensity of the CⅡ 657.8 nm line was achieved by the Fowler–Milne method with the help of an oxygen atomic line of 777.2 nm.The highest temperature obtained in the arc center was up to 19 900 K when the arc current was 400 A and the CO2 flow rate was 50 1 min^-1, while the lowest temperature in the arc center was about 15 900 K when the arc current was 200 A and the CO2 flow rate was 150 1min^-1. The results indicate that as the arc current increases, the temperature in the arc center would also increase apparently, and a larger gas flow rate would lead to a lower central temperature in general. It can also be found that the influence of the CO2 flow rate on the arc temperature was much less than that of the arc current under the present experimental conditions. In addition,higher temperature in the arc center would cause a sharper temperature decrease from the central region towards the edge. 展开更多
关键词 blown co2 arc optical emission spectroscopy temperature distribution ABSOLUTE intensity METHOD FowlerMilne METHOD
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The impact of connate water saturation and salinity on oil recovery and CO2 storage capacity during carbonated water injection in carbonate rock 被引量:4
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作者 Mahmood Shakiba Masoud Riazi +1 位作者 Shahab Ayatollahi Mostafa Takband 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第7期1699-1707,共9页
Carbonated water injection(CWI)is known as an efficient technique for both CO2 storage and enhanced oil recovery(EOR).During CWI process,CO2 moves from the water phase into the oil phase and results in oil swelling.Th... Carbonated water injection(CWI)is known as an efficient technique for both CO2 storage and enhanced oil recovery(EOR).During CWI process,CO2 moves from the water phase into the oil phase and results in oil swelling.This mechanism is considered as a reason for EOR.Viscous fingering leading to early breakthrough and leaving a large proportion of reservoir un-swept is known as an unfavorable phenomenon during flooding trials.Generally,instability at the interface due to disturbances in porous medium promotes viscous fingering phenomenon.Connate water makes viscous fingers longer and more irregular consisting of large number of tributaries leading to the ultimate oil recovery reduction.Therefore,higher in-situ water content can worsen this condition.Besides,this water can play as a barrier between oil and gas phases and adversely affect the gas diffusion,which results in EOR reduction.On the other hand,from gas storage point of view,it should be noted that CO2 solubility is not the same in the water and oil phases.In this study for a specified water salinity,the effects of different connate water saturations(Swc)on the ultimate oil recovery and CO2 storage capacity during secondary CWI are being presented using carbonate rock samples from one of Iranian carbonate oil reservoir.The results showed higher oil recovery and CO2 storage in the case of lower connate water saturation,as 14%reduction of Swc resulted in 20%and 16%higher oil recovery and CO2 storage capacity,respectively. 展开更多
关键词 Carbonated WATER Connate WATER CARBONATE RESERVOIR Enhanced oil RECOVERY Secondary RECOVERY co2 storage
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Characterizing the catalyst fluidization with field synergy to improve the amine absorption for CO2 capture 被引量:1
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作者 Yunsong Yu Chen Zhang +1 位作者 Zaoxiao Zhang Geoff Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第7期1608-1617,共10页
There are great interests to capture the CO2 to control the greenhouse gas emission.Amine absorption of CO2 is being taken as an effective way to capture CO2 in industry.However,the amine absorption of CO2 is cost-ine... There are great interests to capture the CO2 to control the greenhouse gas emission.Amine absorption of CO2 is being taken as an effective way to capture CO2 in industry.However,the amine absorption of CO2 is cost-ineffective due to great energy consumption and solution consumption.In order to reduce the capture cost,catalyst fluidization is proposed here to intensify the mass transfer and heat transfer.Catalyst fluidization with field synergy and DFT model is developed by incorporating the effects of catalyst reaction kinetics,drag force and multi-field into the mass transfer,heat transfer,fluid flow and catalyst collision.Experiments with an improved distributor are performed well to validate the model.The reaction kinetics is determined by the DFT simulation and experiment.The mass transfer coefficient in the fluidized reactor is identified as 17%higher than the conventional packed reactor.With the field synergy of catalyst fluidization,the energy consumption for CO2 desorption is reduced by 9%.Stepwise operation and inclination reactor are used to improve catalyst fluidization process. 展开更多
关键词 co2 CAPTURE CATALYST FLUIDIZATION Mass transfer DFT Energy CONSUMPTION Field SYNERGY
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Effects of Anthropogenic CO2 and Thermally-Induced CO2 on Global Warming
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作者 Masaharu Nishioka 《Atmospheric and Climate Sciences》 2024年第3期317-327,共11页
Changes in CO2 and temperature are correlated, but it is difficult to observe which is the cause and which is the effect. The release of CO2 dissolved in the ocean into the atmosphere depends on the atmospheric temper... Changes in CO2 and temperature are correlated, but it is difficult to observe which is the cause and which is the effect. The release of CO2 dissolved in the ocean into the atmosphere depends on the atmospheric temperature. However, examining the relationship between changes in CO2 caused by other phenomena and temperature is difficult. Studies of soil respiration (Rs) since the late 20th century have shown that CO2 emissions from soil respiration (Rs) are overwhelmingly greater than CO2 emissions from fossil fuel combustion. This is also noted in the IPCC carbon budget assessment. In this paper, the dependences of Rs on temperature, time, latitude, precipitation, seasons, etc., were investigated using the latest NASA database. The changes in temperature and Rs correlated well. There is also a good correlation between Rs and CO2 generation. Therefore, an increase in temperature results in an increase in CO2. On the other hand, there is no evidence other than model calculations that an increase in anthropogenic CO2 is mainly linked to a rise in temperature. The idea that global warming is caused by anthropogenic CO2 production is still a hypothesis. For these reasons, the relationship between global warming and anthropogenic CO2 should be reconsidered based on physical evidence without preconceptions. . 展开更多
关键词 Global Warming Anthropogenic co2 Thermally-Induced co2 Soil Respiration Carbon Cycles
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Cross-Correlation between Global Temperature and Atmospheric CO2 with a Temperature-Leading Time Lag
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作者 Masaharu Nishioka 《Atmospheric and Climate Sciences》 2024年第4期484-494,共11页
The temperature change and rate of CO2 change are correlated with a time lag, as reported in a previous paper. The correlation was investigated by calculating a correlation coefficient r of these changes for selected ... The temperature change and rate of CO2 change are correlated with a time lag, as reported in a previous paper. The correlation was investigated by calculating a correlation coefficient r of these changes for selected ENSO events in this study. Annual periodical increases and decreases in the CO2 concentration were considered, with a regular pattern of minimum values in August and maximum values in May each year. An increased deviation in CO2 and temperature was found in response to the occurrence of El Niño, but the increase in CO2 lagged behind the change in temperature by 5 months. This pattern was not observed for La Niña events. An increase in global CO2 emissions and a subsequent increase in global temperature proposed by IPCC were not observed, but an increase in global temperature, an increase in soil respiration, and a subsequent increase in global CO2 emissions were noticed. This natural process can be clearly detected during periods of increasing temperature specifically during El Niño events. The results cast strong doubts that anthropogenic CO2 is the cause of global warming. 展开更多
关键词 Global Warming Thermally-Induced co2 Soil Respiration Cross-Correlation Coefficient Time Lag El Niño
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Cerium-modified Ni-La2O3/ZrO2 for CO2 methanation 被引量:3
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作者 Shuangshuang Li Guilong Liu +4 位作者 Siran Zhang Kang An Zhi Ma Luhui Wang Yuan Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第4期155-164,共10页
The key point in CO2 methanation is to improve the activity at low temperature and the stability.For this purpose,a new cerium-modified Ni-La2O3/ZrO2 catalyst was prepared using La1-xCexNiO3/ZrO2 with perovskite phase... The key point in CO2 methanation is to improve the activity at low temperature and the stability.For this purpose,a new cerium-modified Ni-La2O3/ZrO2 catalyst was prepared using La1-xCexNiO3/ZrO2 with perovskite phase as the precursor,which was obtained by citrate complexation combined with an impregnation method.The resulting catalyst was characterized through Nitrogen adsorption and desorption,X-ray diffraction (XRD),Transmission electron microscopy (TEM),Hydrogen temperature programmed reduction (H2-TPR),Temperature-programmed desorption of CO2 (CO2-TPD) and that of H2 (H2-TPD),and X-ray photoelectron spectroscopy (XPS) techniques,and the catalytic performances for CO2 methanation was investigated.Cerium modification could improve the effective activation of CO2,thus enhancing the activity at low temperature for CO2 methanation.The metal Ni nanoparticles prepared using this method were highly dispersed and showed excellent resistance to sintering,leading to very good stability,which could be attributed to the following:Ni nanoparticles could be confined by cerium-modified La2O3;La2O3could be confined by the cerium ions at the La2O3/ZrO2 interface;and the cerium ions were confined by ZrO2. 展开更多
关键词 co2 METHANATION CERIUM PEROVSKITE-TYPE oxide Resistance to sintering Nickel Additive
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Enhanced CO2 decomposition via metallic foamed electrode packed in self-cooling DBD plasma device 被引量:3
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作者 Shengjie ZHU Amin ZHOU +2 位作者 Feng YU Bin DAI Cunhua MA 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第8期82-88,共7页
A self-cooling dielectric barrier discharge reactor, packed with foamed Cu and Ni mesh and operated at ambient conditions, was used for the composition of CO2 into CO and O2.The influences of power, frequency, and oth... A self-cooling dielectric barrier discharge reactor, packed with foamed Cu and Ni mesh and operated at ambient conditions, was used for the composition of CO2 into CO and O2.The influences of power, frequency, and other discharge characteristics were investigated in order to have a better understanding of the effect of the packing materials on CO2 decomposition.It is found that porous foamed Cu and Ni not only played a role as the carrier of energy transformation and electrode distributed in discharge gaps but also promoted the equilibrium shifting toward the product side to yield more CO by consuming some part of O2 and O radicals generated from the decomposition of CO2.The maximum CO2 decomposition rates of 48.6%and 49.2% and the maximum energy efficiency of 9.71% and 10.18% were obtained in the foamed Ni and Cu mesh, respectively. 展开更多
关键词 dielectric BARRIER DISCHARGE co2 DECOMPOSITION metallic foamed materials energy efficiency
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Calculation of the Phase Equilibrium of CO2–Hydrocarbon Binary Mixtures by PR-BM EOS and PR EOS 被引量:2
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作者 Chuanyan Li Yahui Gao +2 位作者 Shuqian Xia Qiaoyan Shang Peisheng Ma 《Transactions of Tianjin University》 EI CAS 2019年第5期540-548,共9页
The phase equilibrium data of CO2 hydrocarbon binary mixtures are important for the design and operation of CO 2 ood- ing, coal liquefaction, and supercritical extraction processes. Numerous pieces of binary phase equ... The phase equilibrium data of CO2 hydrocarbon binary mixtures are important for the design and operation of CO 2 ood- ing, coal liquefaction, and supercritical extraction processes. Numerous pieces of binary phase equilibrium data have been obtained. Thus, models for the accurate calculation of binary and multicomponent mixtures must be developed on the basis of existing data. In this work, 3578 vapor liquid phase equilibrium data points for 10 CO 2 hydrocarbon binary mixtures, including CO2 butane, CO 2 pentane, CO 2 isopentane, C O 2 hexane, CO 2 benzene, CO 2 heptane, CO 2 octane, C O 2 non- ane, CO 2 decane, and C O 2 undecane, were collected. The PR and PR-BM equations of state (EOS) in combination with relevant mixing rules were used to calculate the phase equilibrium data of the CO 2 hydrocarbon binary mixtures. The binary interaction parameter k ij in the PR EOS was temperature independent, whereas parameters in the PR-BM EOS were functions of temperature. Thus, the phase equilibrium data and other thermodynamic properties of the binary and multicomponent mixtures at di erent temperatures and pressures can be calculated by using the parameters obtained in this work. The PR-BM EOS performed better than the PR EOS, and the average absolute deviations over the temperature range of 255.98 408.15 K calculated by the PR EOS and PR-BM EOS were less than 5.74% and 3.36%, respectively. The results calculated by the two EOS were compared with those calculated by other models, such as PPR78, PR + LCVM + UNIFAC, KIE + PR EOS + HV, and PSRK. The phase equilibrium data of CO 2 butane decane, CO 2 hexane decane, and C O 2 octane decane ternary mixtures were calculated by the two EOS. The average overall deviations for the CO 2 mole fractions calculated by the two EOS were less than 7.66%. 展开更多
关键词 Phase EQUILIBRIUM EQUATION of state MIXING RULE HYDROCARBON CO 2
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A Review on Technologies for the Use of CO2 as a Working Fluid in Refrigeration and Power Cycles
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作者 Orelien T. Boupda Hyacinthe D. Tessemo +3 位作者 Isidore B. Nkounda Fongang Francklin G. Nyami Frederic Lontsi Thomas Djiako 《Energy and Power Engineering》 2024年第6期217-256,共40页
The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its ther... The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its thermodynamic properties make it a fluid of choice in the efficient use of energy at low and medium temperatures in engine cycles. However, the performance of transcritical CO2 cycles weakens under high temperature and pressure conditions, especially in refrigeration systems;On the other hand, this disadvantage becomes rather interesting in engine cycles where CO2 can be used as an alternative to the organic working fluid in small and medium-sized electrical systems for low quality or waste heat sources. In order to improve the performance of systems operating with CO2 in the field of refrigeration and electricity production, research has made it possible to develop several concepts, of which this article deals with a review of the state of the art, followed by analyzes in-depth and critical of the various developments to the most recent modifications in these fields. Detailed discussions on the performance and technical characteristics of the different evolutions are also highlighted as well as the factors affecting the overall performance of the systems studied. Finally, perspectives on the future development of the use of CO2 in these different cycles are presented. 展开更多
关键词 Refrigeration Cycle Power Cycle System Performance Transcritical co2 Cycles Working Fluid
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The role of CO2 and ion type in the dynamic interfacial tension of acidic crude oil/carbonated brine
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作者 Mostafa Lashkarbolooki Ali Zeinolabedini Hezave Shahab Ayatollahi 《Petroleum Science》 SCIE CAS CSCD 2019年第4期850-858,共9页
The e ects of CO2 and salt type on the interfacial tension(IFT) between crude oil and carbonated brine(CB) have not been fully understood. This study focuses on measuring the dynamic IFT between acidic crude oil with ... The e ects of CO2 and salt type on the interfacial tension(IFT) between crude oil and carbonated brine(CB) have not been fully understood. This study focuses on measuring the dynamic IFT between acidic crude oil with a total acid number of 1.5 mg KOH/g and fully CO2-saturated aqueous solutions consisting of 15,000 ppm of KCl, NaCl, CaCl2 and MgCl2 at 30 °C and a wide range of pressures(500–4000 psi). The results of IFT measurements showed that solvation of CO2 into all the studied aqueous solutions led to an increase in IFT of acidic crude oil(i.e., comparison of IFT of crude oil/CB and crude oil/brine), while no significant e ect was observed for pressure. In contrast, the obtained results of studied salts indicated a positive e ect on the IFT reduction of acidic crude oil/carbonated water(CW)(i.e., comparison of IFT of crude oil/CB and crude oil/CW). 展开更多
关键词 Carbonated BRINE Interfacial tension Crude OIL Enhanced OIL recovery(EOR) co2 SEQUESTRATION
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Recent advances on first-principles modeling for the design of materials in CO2 capture technologies 被引量:5
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作者 Yue Yuan Huabei You Luis Ricardez-Sandoval 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第7期1554-1565,共12页
Novel technologies in consideration of industrial sustainability(IS)are in urgent need to satisfy the increasing demands from the society.IS realizes the production of materials while maintaining environmental and res... Novel technologies in consideration of industrial sustainability(IS)are in urgent need to satisfy the increasing demands from the society.IS realizes the production of materials while maintaining environmental and resource sustainability.The chemical materials used in CO2 capture and storage(CCS)technologies play a significant role in the disposal of greenhouse gas emissions coming from large stationary fossil-fired power plants,which breaks the principle of IS and brings severe environmental problems.This study aims at providing a detailed review of first-principles modeling(density functional theory,DFT)of materials in CO2 capture technologies.DFT analysis provides insight into the atomic properties of the studied systems and builds an efficient guidance of the future design of the materials used in CO2 capture technologies.Major materials including oxygen carriers,metal organic frameworks,membranes,zeolites,ionic liquids and some other promising candidates are considered.The computational studies bring the outcomes of the adsorption behaviors,structural characteristics and accurate force fields of the studied materials in short turn-around times at low cost.This review can stimulate the design of novel materials with specific target of CO2 capture and promote the industrial sustainability of fossil fuel combustion technologies. 展开更多
关键词 Industrial SUSTAINABILITY co2 CAPTURE DENSITY FUNCTIONAL theory FOSSIL fuels
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ZrO2 nanoparticles anchored on nitrogen-doped carbon nanosheets as efficient catalyst for electrochemical CO2 reduction 被引量:4
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作者 Zhengpei Miao Pei Hu +3 位作者 Chuanye Nie Huan Xie Wenli Fu Qing Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第11期114-118,共5页
Electrochemical reduction of CO2 to produce value-added feedstock chemicals using high-performance electrocatalysts is a promising protocol to address the excessive CO2 in the atmosphere and the energy crisis. However... Electrochemical reduction of CO2 to produce value-added feedstock chemicals using high-performance electrocatalysts is a promising protocol to address the excessive CO2 in the atmosphere and the energy crisis. However, the high overpotential, low current density, and poor product selectivity for CO2 electroreduction greatly impede their practical applications. In this work, we develop an efficient catalyst for CO2 reduction to CO consisting of well-dispersed ZrO2 nanoparticles tightly anchored on nitrogendoped carbon nanosheets(ZrO2/N-C) for the first time. Importantly, the ZrO2 nanoparticles possess oxygen vacancies and defects, which regulate the electronic structure of catalyst and thus greatly enhance the electrocatalytic activity. Specifically, ZrO2/N-C demonstrates a high CO Faradaic efficiency(FE) of 64% at-0.4 V vs. the reversible hydrogen electrode(RHE) and a respectable current density of ~2.6 m A cm-2 in CO2-saturated 0.5 M KHCO 3 solution. This work opens a new avenue for developing excellent catalysts for CO2 electroreduction with metal oxide/heteroatom-doped carbon composite structure. 展开更多
关键词 ZIRCONIUM oxide co2 REDUCTION ELECTROCATALYSIS Nitrogen doping Faradaic efficiency
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Electrochemical CO2 reduction over nitrogen-doped SnO2 crystal surfaces 被引量:4
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作者 Yuefeng Zhang Jianjun Liu +3 位作者 Zengxi Wei Quanhui Liu Caiyun Wang Jianmin Ma 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第6期22-30,共9页
Crystal planes of a catalyst play crucial role in determining the electrocatalytic performance for CO2 reduction.The catalyst SnO2 can convert CO2 molecules into valuable formic acid(HCOOH).Incorporating heteroatom N ... Crystal planes of a catalyst play crucial role in determining the electrocatalytic performance for CO2 reduction.The catalyst SnO2 can convert CO2 molecules into valuable formic acid(HCOOH).Incorporating heteroatom N into SnO2 further improves its catalytic activity.To understand the mechanism and realize a highly efficient CO2-to-HCOOH conversion,we used density functional theory(DFT)to calculate the free energy of CO2 reduction reactions(CO2RR)on different crystal planes of N-doped SnO2(N-SnO2).The results indicate that N-SnO2 lowered the activation energy of intermediates leading to a better catalytic performance than pure SnO2.We also discovered that the N-Sn O2 (211)plane possesses the most suitable free energy during the reduction process,exhibiting the best catalytic ability for the CO2-to-HCOOH conversion.The intermediate of CO2RR on N-SnO2 is HCOO*or COOH* instead of OCHO*.These results may provide useful insights into the mechanism of CO2RR,and promote the development of heteroatomdoped catalyst for efficient CO2RR. 展开更多
关键词 co2 REDUCTION reaction SNO2 Crystal surface ELECTROCATALYSIS First PRINCIPLES
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Theoretical study of CO2 hydrogenation to methanol on isolated small Pdx clusters 被引量:2
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作者 Adhitya G.Saputro Refaldi I.D.Putra +5 位作者 Arifin L.Maulana Muhammad U.Karami Mochamad R.Pradana Mohammad K.Agusta Hermawan K.Dipojono Hideaki Kasai 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第8期79-87,I0004,共10页
CO2 hydrogenation to methanol on small size Pdxclusters(x = 7, 9 and 13) has been studied using density functional theory calculations. It has been found that in contrast to metallic Pd system, these small Pdxclusters... CO2 hydrogenation to methanol on small size Pdxclusters(x = 7, 9 and 13) has been studied using density functional theory calculations. It has been found that in contrast to metallic Pd system, these small Pdxclusters can interact well with CO2 molecule. CO2 molecule can be adsorbed with a bidendate configuration on the Pdxclusters. The formation of CO2 bidendate adsorption configuration facilitates the first step of CO2 hydrogenation reaction on the clusters. The energy profiles for formate pathway and reverse water gas shift + CO hydrogenation pathways on Pdxclusters are quite similar with Cu(111) surface, except for the first and last hydrogenation steps where the Pdxclusters have lower activation energies. This improvement causing the Pdxclusters to have a tolerable turn over frequencies values. In general, the usage of Pd in the form of small size cluster can improve the catalytic performance of metallic Pd for the CO2 hydrogenation to methanol because small size Pd cluster can act not only as an H2 dissociation center but also as a CO2 hydrogenation center. 展开更多
关键词 Pdx CLUSTERS co2 ADSORPTION HYDROGENATION METHANOL Density functional theory
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新型煤气化燃烧集成制氢系统的热力学研究 被引量:35
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作者 王智化 王勤辉 +3 位作者 骆仲泱 周俊虎 樊建人 岑可法 《中国电机工程学报》 EI CSCD 北大核心 2005年第12期91-97,共7页
对于以CaO为CO2接受体的无氧气化法为基础的新型煤气化燃烧集成制氢系统进行了化学热力学分析,以化学热力学平衡为基础研究了温度、压力、煤种、H2O/C比对制氢过程的影响.计算结果表明CaO的加入在一定条件下可以大大提高H2产量,气化过... 对于以CaO为CO2接受体的无氧气化法为基础的新型煤气化燃烧集成制氢系统进行了化学热力学分析,以化学热力学平衡为基础研究了温度、压力、煤种、H2O/C比对制氢过程的影响.计算结果表明CaO的加入在一定条件下可以大大提高H2产量,气化过程的温度过高会引起CaCO3的重新分解,而温度过低则降低H2产量,合适的温度为850℃左右,合适的压力范围为2~3MPa.以纯碳为原料、气化炉中碳转化率为69%时,半焦燃烧的热量可以满足CaCO3的分解.当H2O/C在3.0~3.5之间时,气化效率达到79%左右,制氢效率为65%左右,产品气中H2含量为85%左右.与烟煤、褐煤相比,无烟煤为原料时产品气中H2含量最高,接近于以纯碳为原料的工况,而褐煤由于挥发份中CH4的含量多导致H2含量降低. 展开更多
关键词 CACO3 CaO H2O co2 CH4
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Selective electrocatalytic CO2 reduction enabled by SnO2 nanoclusters 被引量:4
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作者 Hui Yang Yang Huang +5 位作者 Jun Deng Yunling Wu Na Han Chenyang Zha Leigang Li Yanguang Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第10期93-96,共4页
The development of high-performance electrocatalysts holds the decisive key to the electrochemical CO2 reduction toward value-added products. Formic acid or formate is a desirable reduction product, but its selective ... The development of high-performance electrocatalysts holds the decisive key to the electrochemical CO2 reduction toward value-added products. Formic acid or formate is a desirable reduction product, but its selective production is often challenging. Tin based-materials have attracted great attention for formate production, and yet their performances are far from satisfactory. In this study, we reported the preparation of SnO2 nanoclusters from the controlled self-polymerization of dopamine together with SnO32-, followed by the mild-temperature calcination. The final product consisted of large primary particles that were further made of small secondary SnO2 nanocrystals. When evaluated as the electrocatalyst for CO2 reduction in 0.5 M NaHCO3, our material exhibited impressive activity, selectivity and stability for the selective CO2 reduction to formate. A peak formate Faradaic efficiency of^73% and large partial current density of 16.3 mA/cm2 was achieved at -0.92 V versus reversible hydrogen electrode. 展开更多
关键词 co2 REDUCTION reaction ELECTROCATALYSTS FORMATE Tin oxide Selectivity
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Low-overpotential selective reduction of CO2 to ethanol on electrodeposited CuxAuy nanowire arrays 被引量:4
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作者 Weiwei Zhu Kuangmin Zhao +7 位作者 Suqin Liu Min Liu Feng Peng Pengda An Binhao Qin Huimin Zhou Hongmei Li Zhen He 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第10期176-182,共7页
Direct electrochemical reduction of CO2 to multicarbon products is highly desirable, yet challenging. Here, we present a potentiostatic pulse-electrodeposition of high-aspect-ratio CuxAuy nanowire arrays (NWAs) as hig... Direct electrochemical reduction of CO2 to multicarbon products is highly desirable, yet challenging. Here, we present a potentiostatic pulse-electrodeposition of high-aspect-ratio CuxAuy nanowire arrays (NWAs) as high-performance electrocatalysts for the CO2 reduction reaction (CO2RR). The surface electronic structure related to the Cu:Au ratio in the CuxAuy NWAs could be facilely modulated by controlling the electrodeposition potential and the as-fabricated CuxAuy NWAs could be directly used as the catalytic electrode for the CO2RR. The morphology of the high-aspect-ratio nanowire array significantly lowers the onset potential of the alcohol formation due to the diffusion-induced enhancement of the local pH and CO concentration near the nanowire surface. Besides, the properly adjusted surface electronic structure of the CuxAuy NWA enables the adsorption of CO and facilitates the subsequent CO reduction to ethanol via the C-C coupling pathway. Owing to the synergistic effect of morphology and electronic structure, the optimized CuxAuy NWA selectively reduces CO2 to ethanol at low potentials of -0.5——0.7 V vs. RHE with a highest Faradaic efficiency of 48%. This work demonstrates the feasibility to optimize the activity and selectivity of the Cu-based electrocatalysts toward multicarbon alcohols for the CO2RR via simultaneous adjustment of the electronic structure and morphology of the catalysts. 展开更多
关键词 co2 reduction ELECTROCATALYSIS NANOWIRE array SELECTIVITY Cu-based catalyst
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