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Meihong Wang - One of the best experts on this subject based on the ideXlab platform.
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conventional and advanced exergy analysis of post combustion co 2 capture based on Chemical Absorption integrated with supercritical coal fired power plant
International Journal of Greenhouse Gas Control, 2017Co-Authors: Akeem K Olaleye, Meihong WangAbstract:Abstract Post-combustion CO2 capture (PCC) based on Chemical Absorption is one of the strategic technologies identified to reduce emission of greenhouse gases from various power plants. However, PCC based on Chemical Absorption incurs serious energy penalty due to the use of energy for solvent regeneration. Reducing the energy/exergy use in this process can reduce energy penalties. It is also important to increase the efficiency of the CO2 capture system. This study focuses on: steady state simulation of a closed-loop PCC plant integrated with supercritical coal-fired power plant (SCPP); conventional and advanced exergy analyses of the PCC; and case studies on strategies to reduce exergy destruction in the system components. The conventional exergy analysis evaluates the amount and location of exergy destruction within the whole system. The advanced exergetic analysis estimates the sources of the exergy destruction in individual component or the whole system and the potential for reducing it. The results show that the energy consumption and the efficiency of the PCC process can be improved by recovering the avoidable exergy destroyed in the system components. This is important because for every 1% reduction in the energy required for capture, costs can be lowered to between 0.7–1%.
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process intensification for post combustion co2 capture with Chemical Absorption a critical review
Applied Energy, 2015Co-Authors: Meihong Wang, C Ramshaw, Atuman Samaila Joel, Dag Eimer, Nuhu Mamman MusaAbstract:The concentration of CO2 in the atmosphere is increasing rapidly. CO2 emissions may have an impact on global climate change. Effective CO2 emission abatement strategies such as carbon capture and storage (CCS) are required to combat this trend. Compared with pre-combustion carbon capture and oxy-fuel carbon capture approaches, post-combustion CO2 capture (PCC) using solvent process is one of the most mature carbon capture technologies. There are two main barriers for the PCC process using solvent to be commercially deployed: (a) high capital cost; (b) high thermal efficiency penalty due to solvent regeneration. Applying process intensification (PI) technology into PCC with solvent process has the potential to significantly reduce capital costs compared with conventional technology using packed columns. This paper intends to evaluate different PI technologies for their suitability in PCC process. The study shows that rotating packed bed (RPB) absorber/stripper has attracted much interest due to its high mass transfer capability. Currently experimental studies on CO2 capture using RPB are based on standalone absorber or stripper. Therefore a schematic process flow diagram of intensified PCC process is proposed so as to motivate other researches for possible optimal design, operation and control. To intensify heat transfer in reboiler, spinning disc technology is recommended. To replace cross heat exchanger in conventional PCC (with packed column) process, printed circuit heat exchanger will be preferred. Solvent selection for conventional PCC process has been studied extensively. However, it needs more studies for solvent selection in intensified PCC process. The authors also predicted research challenges in intensified PCC process and potential new breakthrough from different aspects.
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dynamic modelling validation and analysis of post combustion Chemical Absorption co2 capture plant
International Journal of Greenhouse Gas Control, 2012Co-Authors: Chechet Biliyok, Meihong Wang, Adekola Lawal, Frank SeibertAbstract:Abstract Development of dynamic models for post-combustion CO2 capture using monoethanolamine solvent has been reported in the literature. Such models are only validated at steady-state, which means the models can predict process performance at different operating points. However, without dynamic validation, there is no guarantee that the model in question would predict dynamic responses accurately. This paper presents a dynamic validation study. The absorber and regenerator were modelled to account for mass transfer with Chemical reactions assumed at equilibrium. Plant data logs were provided by the University of Texas at Austin. Three cases were considered: a conventional process and two cases with intercooled absorbers. The absorber temperature profile, capture level and reboiler duty were used for comparison. It is observed that the model satisfactorily predicts the pilot plant behaviour under multiple process inputs and disturbances. The validated model was then used to analyse the effect of increasing inlet flue gas moisture content and the impact of effective intercooling on the process performance. The former marginally influences the capture level, but significantly affects temperature profile, hence is an important parameter in model validation. The latter enhances capture level, and provides evidence that CO2 Absorption is mass transfer limited.
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post combustion co2 capture with Chemical Absorption a state of the art review
Chemical Engineering Research & Design, 2011Co-Authors: Meihong Wang, Adekola Lawal, Pete Stephenso, J Sidders, C RamshawAbstract:Abstract Global concentration of CO2 in the atmosphere is increasing rapidly. CO2 emissions have an impact on global climate change. Effective CO2 emission abatement strategies such as Carbon Capture and Storage (CCS) are required to combat this trend. There are three major approaches for CCS: post-combustion capture, pre-combustion capture and oxyfuel process. Post-combustion capture offers some advantages as existing combustion technologies can still be used without radical changes on them. This makes post-combustion capture easier to implement as a retrofit option (to existing power plants) compared to the other two approaches. Therefore, post-combustion capture is probably the first technology that will be deployed. This paper aims to provide a state-of-the-art assessment of the research work carried out so far in post-combustion capture with Chemical Absorption. The technology will be introduced first, followed by required preparation of flue gas from power plants to use this technology. The important research programmes worldwide and the experimental studies based on pilot plants will be reviewed. This is followed by an overview of various studies based on modelling and simulation. Then the focus is turned to review development of different solvents and process intensification. Based on these, we try to predict challenges and potential new developments from different aspects such as new solvents, pilot plants, process heat integration (to improve efficiency), modelling and simulation, process intensification and government policy impact.
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dynamic modelling and analysis of post combustion co2 Chemical Absorption process for coal fired power plants
Fuel, 2010Co-Authors: Adekola Lawal, Meihong Wang, Peter Stephenson, G Koumpouras, Hoi YeungAbstract:Abstract Post-combustion capture by Chemical Absorption using MEA solvent remains the only commercial technology for large scale CO2 capture for coal-fired power plants. This paper presents a study of the dynamic responses of a post-combustion CO2 capture plant by modelling and simulation. Such a plant consists mainly of the absorber (where CO2 is Chemically absorbed) and the regenerator (where the Chemical solvent is regenerated). Model development and validation are described followed by dynamic analysis of the absorber and regenerator columns linked together with recycle. The gPROMS (Process Systems Enterprise Ltd.) advanced process modelling environment has been used to implement the proposed work. The study gives insights into the operation of the absorber–regenerator combination with possible disturbances arising from integrated operation with a power generation plant. It is shown that the performance of the absorber is more sensitive to the molar L/G ratio than the actual flow rates of the liquid solvent and flue gas. In addition, the importance of appropriate water balance in the absorber column is shown. A step change of the reboiler duty indicates a slow response. A case involving the combination of two fundamental CO2 capture technologies (the partial oxyfuel mode in the furnace and the post-combustion solvent scrubbing) is studied. The flue gas composition was altered to mimic that observed with the combination. There was an initial sharp decrease in CO2 Absorption level which may not be observed in steady-state simulations.
Adekola Lawal - One of the best experts on this subject based on the ideXlab platform.
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dynamic modelling validation and analysis of post combustion Chemical Absorption co2 capture plant
International Journal of Greenhouse Gas Control, 2012Co-Authors: Chechet Biliyok, Meihong Wang, Adekola Lawal, Frank SeibertAbstract:Abstract Development of dynamic models for post-combustion CO2 capture using monoethanolamine solvent has been reported in the literature. Such models are only validated at steady-state, which means the models can predict process performance at different operating points. However, without dynamic validation, there is no guarantee that the model in question would predict dynamic responses accurately. This paper presents a dynamic validation study. The absorber and regenerator were modelled to account for mass transfer with Chemical reactions assumed at equilibrium. Plant data logs were provided by the University of Texas at Austin. Three cases were considered: a conventional process and two cases with intercooled absorbers. The absorber temperature profile, capture level and reboiler duty were used for comparison. It is observed that the model satisfactorily predicts the pilot plant behaviour under multiple process inputs and disturbances. The validated model was then used to analyse the effect of increasing inlet flue gas moisture content and the impact of effective intercooling on the process performance. The former marginally influences the capture level, but significantly affects temperature profile, hence is an important parameter in model validation. The latter enhances capture level, and provides evidence that CO2 Absorption is mass transfer limited.
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post combustion co2 capture with Chemical Absorption a state of the art review
Chemical Engineering Research & Design, 2011Co-Authors: Meihong Wang, Adekola Lawal, Pete Stephenso, J Sidders, C RamshawAbstract:Abstract Global concentration of CO2 in the atmosphere is increasing rapidly. CO2 emissions have an impact on global climate change. Effective CO2 emission abatement strategies such as Carbon Capture and Storage (CCS) are required to combat this trend. There are three major approaches for CCS: post-combustion capture, pre-combustion capture and oxyfuel process. Post-combustion capture offers some advantages as existing combustion technologies can still be used without radical changes on them. This makes post-combustion capture easier to implement as a retrofit option (to existing power plants) compared to the other two approaches. Therefore, post-combustion capture is probably the first technology that will be deployed. This paper aims to provide a state-of-the-art assessment of the research work carried out so far in post-combustion capture with Chemical Absorption. The technology will be introduced first, followed by required preparation of flue gas from power plants to use this technology. The important research programmes worldwide and the experimental studies based on pilot plants will be reviewed. This is followed by an overview of various studies based on modelling and simulation. Then the focus is turned to review development of different solvents and process intensification. Based on these, we try to predict challenges and potential new developments from different aspects such as new solvents, pilot plants, process heat integration (to improve efficiency), modelling and simulation, process intensification and government policy impact.
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dynamic modelling and analysis of post combustion co2 Chemical Absorption process for coal fired power plants
Fuel, 2010Co-Authors: Adekola Lawal, Meihong Wang, Peter Stephenson, G Koumpouras, Hoi YeungAbstract:Abstract Post-combustion capture by Chemical Absorption using MEA solvent remains the only commercial technology for large scale CO2 capture for coal-fired power plants. This paper presents a study of the dynamic responses of a post-combustion CO2 capture plant by modelling and simulation. Such a plant consists mainly of the absorber (where CO2 is Chemically absorbed) and the regenerator (where the Chemical solvent is regenerated). Model development and validation are described followed by dynamic analysis of the absorber and regenerator columns linked together with recycle. The gPROMS (Process Systems Enterprise Ltd.) advanced process modelling environment has been used to implement the proposed work. The study gives insights into the operation of the absorber–regenerator combination with possible disturbances arising from integrated operation with a power generation plant. It is shown that the performance of the absorber is more sensitive to the molar L/G ratio than the actual flow rates of the liquid solvent and flue gas. In addition, the importance of appropriate water balance in the absorber column is shown. A step change of the reboiler duty indicates a slow response. A case involving the combination of two fundamental CO2 capture technologies (the partial oxyfuel mode in the furnace and the post-combustion solvent scrubbing) is studied. The flue gas composition was altered to mimic that observed with the combination. There was an initial sharp decrease in CO2 Absorption level which may not be observed in steady-state simulations.
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dynamic modelling of co2 Absorption for post combustion capture in coal fired power plants
Fuel, 2009Co-Authors: Adekola Lawal, Meihong Wang, Peter Stephenson, Hoi YeungAbstract:Abstract Power generation from fossil fuel-fired power plants is the largest single source of CO 2 emissions. Post combustion capture via Chemical Absorption is viewed as the most mature CO 2 capture technique. This paper presents a study of the post combustion CO 2 capture with monoethanolamine (MEA) based on dynamic modelling of the process. The aims of the project were to compare two different approaches (the equilibrium-based approach versus the rate-based approach) in modelling the absorber dynamically and to understand the dynamic behaviour of the absorber during part load operation and with disturbances from the stripper. A powerful modelling and simulation tool gPROMS was chosen to implement the proposed work. The study indicates that the rate-based model gives a better prediction of the Chemical Absorption process than the equilibrium-based model. The dynamic simulation of the absorber indicates normal absorber column operation could be maintained during part load operation by maintaining the ratio of the flow rates of the lean solvent and flue gas to the absorber. Disturbances in the CO 2 loading of the lean solvent to the absorber significantly affect absorber performance. Further work will extend the dynamic modelling to the stripper for whole plant analysis.
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dynamic modeling and simulation of co2 Chemical Absorption process for coal fired power plants
Computer-aided chemical engineering, 2009Co-Authors: Adekola Lawal, Meihong Wang, Peter Stephenson, Hoi YeungAbstract:Post combustion capture via Chemical Absorption is viewed as the most mature CO2 capture technique. The effects of the addition of CO2 Chemical Absorption process on power plant performance have been studied using various steady-state models. However, there are several gaps in the understanding of the impact of post combustion capture on the operability of the power plant. These questions could be addressed by studying the dynamic behavior of such plants. In this study, dynamic models of the CO2 Chemical Absorption process were developed and validated. Dynamic analyses of the process reveal that absorber performance is sensitive to L/G ratio and that changes in reboiler duty significantly affect the regenerator performance.
Hoi Yeung - One of the best experts on this subject based on the ideXlab platform.
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dynamic modelling and analysis of post combustion co2 Chemical Absorption process for coal fired power plants
Fuel, 2010Co-Authors: Adekola Lawal, Meihong Wang, Peter Stephenson, G Koumpouras, Hoi YeungAbstract:Abstract Post-combustion capture by Chemical Absorption using MEA solvent remains the only commercial technology for large scale CO2 capture for coal-fired power plants. This paper presents a study of the dynamic responses of a post-combustion CO2 capture plant by modelling and simulation. Such a plant consists mainly of the absorber (where CO2 is Chemically absorbed) and the regenerator (where the Chemical solvent is regenerated). Model development and validation are described followed by dynamic analysis of the absorber and regenerator columns linked together with recycle. The gPROMS (Process Systems Enterprise Ltd.) advanced process modelling environment has been used to implement the proposed work. The study gives insights into the operation of the absorber–regenerator combination with possible disturbances arising from integrated operation with a power generation plant. It is shown that the performance of the absorber is more sensitive to the molar L/G ratio than the actual flow rates of the liquid solvent and flue gas. In addition, the importance of appropriate water balance in the absorber column is shown. A step change of the reboiler duty indicates a slow response. A case involving the combination of two fundamental CO2 capture technologies (the partial oxyfuel mode in the furnace and the post-combustion solvent scrubbing) is studied. The flue gas composition was altered to mimic that observed with the combination. There was an initial sharp decrease in CO2 Absorption level which may not be observed in steady-state simulations.
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dynamic modelling of co2 Absorption for post combustion capture in coal fired power plants
Fuel, 2009Co-Authors: Adekola Lawal, Meihong Wang, Peter Stephenson, Hoi YeungAbstract:Abstract Power generation from fossil fuel-fired power plants is the largest single source of CO 2 emissions. Post combustion capture via Chemical Absorption is viewed as the most mature CO 2 capture technique. This paper presents a study of the post combustion CO 2 capture with monoethanolamine (MEA) based on dynamic modelling of the process. The aims of the project were to compare two different approaches (the equilibrium-based approach versus the rate-based approach) in modelling the absorber dynamically and to understand the dynamic behaviour of the absorber during part load operation and with disturbances from the stripper. A powerful modelling and simulation tool gPROMS was chosen to implement the proposed work. The study indicates that the rate-based model gives a better prediction of the Chemical Absorption process than the equilibrium-based model. The dynamic simulation of the absorber indicates normal absorber column operation could be maintained during part load operation by maintaining the ratio of the flow rates of the lean solvent and flue gas to the absorber. Disturbances in the CO 2 loading of the lean solvent to the absorber significantly affect absorber performance. Further work will extend the dynamic modelling to the stripper for whole plant analysis.
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dynamic modeling and simulation of co2 Chemical Absorption process for coal fired power plants
Computer-aided chemical engineering, 2009Co-Authors: Adekola Lawal, Meihong Wang, Peter Stephenson, Hoi YeungAbstract:Post combustion capture via Chemical Absorption is viewed as the most mature CO2 capture technique. The effects of the addition of CO2 Chemical Absorption process on power plant performance have been studied using various steady-state models. However, there are several gaps in the understanding of the impact of post combustion capture on the operability of the power plant. These questions could be addressed by studying the dynamic behavior of such plants. In this study, dynamic models of the CO2 Chemical Absorption process were developed and validated. Dynamic analyses of the process reveal that absorber performance is sensitive to L/G ratio and that changes in reboiler duty significantly affect the regenerator performance.
Dianne E Wiley - One of the best experts on this subject based on the ideXlab platform.
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exergetic and exergoeconomic analysis of post combustion co2 capture using mea solvent Chemical Absorption
Energy, 2017Co-Authors: Dianne E Wiley, Giandomenico Ferrara, Andrea Lanzini, Pierluigi LeoneAbstract:Carbon Capture and Storage (CCS) has been acknowledged as a technology for CO2 emission reduction. However, developments to lower cost and energy consumption remains an important challenge. Exergetic and exergoeconomic analyses are methods which could be applied to optimize the energy consumption of CO2 capture technologies. An exergetic analysis reveals the locations and causes of inefficiency in an energy conversion process and provides options for improvements. An exergoeconomic analysis establishes the process of cost formation of different streams, including products, within energy systems based on exergy and economic cost balances. This paper aims to develop an exergy-based analysis of a post-combustion CO2 capture process using Chemical Absorption. A comprehensive flowsheet model has been built for an MEA-solvent Chemical Absorption, using ASPEN PlusTM Version 8.6 for a coal-fired power plant with a capture rate of 90%. Results have shown the highest irreversibilities to occur in the units related to the Chemical capture of CO2 (77% of total losses) and in the CO2 pipeline compressor (9% of total losses). An improvement in the design of the plant reduces the unit cost of carbon capture from 35.0 US$/tonCO2 in the baseline case to of 31.8 US$/tonCO2.
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reducing the cost of co2 capture from flue gases using aqueous Chemical Absorption
Industrial & Engineering Chemistry Research, 2013Co-Authors: Anggit Raksajati, Dianne E WileyAbstract:Chemical Absorption is widely regarded as the most promising technology for CO2 capture from large industrial sources in the short term. The cost of CO2 capture from postcombustion power plants using monoethanolamine (MEA), the benchmark for Chemical Absorption, is currently over US$70 per metric ton of CO2 avoided. This high cost is considered as the major obstacle to current large-scale implementation of carbon capture and storage (CCS). Thus, there has been significant focus on the development of new solvents with the aim to reduce costs. This paper provides insights into the impact of solvent properties on the cost of capture to assist in the development of new solvents based on a 500 MW supercritical black coal power plant as the emission source. The effect of solvent properties, specifically solvent loading, heat of reaction, solvent loss, and solvent concentration is examined. The effect of improvements in process design, specifically high pressure stripper operation, advanced structured packing, u...
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reducing the cost of co2 capture from flue gases using aqueous Chemical Absorption
Industrial & Engineering Chemistry Research, 2013Co-Authors: Anggit Raksajati, Minh T Ho, Dianne E WileyAbstract:Chemical Absorption is widely regarded as the most promising technology for CO2 capture from large industrial sources in the short term. The cost of CO2 capture from postcombustion power plants using monoethanolamine (MEA), the benchmark for Chemical Absorption, is currently over US$70 per metric ton of CO2 avoided. This high cost is considered as the major obstacle to current large-scale implementation of carbon capture and storage (CCS). Thus, there has been significant focus on the development of new solvents with the aim to reduce costs. This paper provides insights into the impact of solvent properties on the cost of capture to assist in the development of new solvents based on a 500 MW supercritical black coal power plant as the emission source. The effect of solvent properties, specifically solvent loading, heat of reaction, solvent loss, and solvent concentration is examined. The effect of improvements in process design, specifically high pressure stripper operation, advanced structured packing, u...
Rong Wang - One of the best experts on this subject based on the ideXlab platform.
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mass transfer study and modeling of gas liquid membrane contacting process by multistage cascade model for co2 Absorption
Separation and Purification Technology, 2008Co-Authors: Supakorn Atchariyawut, Ratana Jiraratananon, Rong WangAbstract:The objective of this work was to characterize the main mass transfer resistance for CO2 capture in the gas–liquid membrane contacting process by both physical and Chemical Absorption conditions. The characterization was performed based on the resistance-in-series model as well as the Wilson-plot method. In addition, a multistage cascade model, which is able to predict the time for the system to reach a steady-state condition, was developed to describe CO2 Absorption in the membrane contacting process. The cascade model was numerically solved by using the MATLAB program. It was found that the main mass transfer resistance of the physical Absorption (using pure water as an absorbent) and the Chemical Absorption (using 2 M NaOH as an absorbent) was in the liquid phase and in the membrane, respectively. The membrane mass transfer resistance in the case of physical Absorption presented approximately 36% of the total resistances at a liquid velocity of 2.13 m/s. For the Chemical Absorption condition applied, the membrane mass transfer resistance occupied around 99% of the total resistance. The results of simulation by the cascade model agreed well with the experimental results when the overall mass transfer coefficient obtained form the experiment was employed. The model can potentially be used with various operating conditions including the liquid velocity, gas concentration, and reactive absorbent used. © 2008 Elsevier B.V. All rights reserved.
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theoretical and experimental studies of membrane wetting in the membrane gas liquid contacting process for co2 Absorption
Journal of Membrane Science, 2008Co-Authors: Hongyan Zhang, Rong Wang, David Tee Liang, Joohwa TayAbstract:Abstract A systematic simulation has been carried out in membrane contactors to study CO 2 capture by water and diethanolamine (DEA) aqueous solutions from a CO 2 /N 2 mixture under the wetted and the non-wetted operation modes. Two types of microporous hollow fiber membrane modules made of polypropylene (PP) and polyvinylidene fluoride (PVDF) hollow fibers were used to conduct CO 2 Absorption experiments. The corresponding experimental data were used to verify simulated results. Experimental study showed that the membrane wetting could not be completely avoided especially in the case of Chemical Absorption. Both experimental and theoretical study disclosed that the membrane wetting would result in a significant drop of CO 2 flux. The simulation results further revealed that for the physical Absorption of CO 2 by water, the proportion of membrane phase resistance in the overall mass transfer resistance increased from less than 5 to about 90% when the operation mode was shifted from non-wetted to wetted. As for the Chemical Absorption, analysis on the mass transfer resistance revealed that the ratio of the membrane resistance increased sharply from 10 to 70% when only 10% membrane length was wetted. With the introduction of an extra resistance caused by the membrane wetting, the mass transfer in the wetted membrane phase finally became the rate-controlling step. It was not as effective to enhance the CO 2 flux by increasing the inlet gas velocity or the liquid velocity as in the non-wetted mode of operation.
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Mass transfer study and modeling of gas-liquid membrane contacting process by multistage cascade model for CO2 Absorption
Separation and Purification Technology, 2008Co-Authors: Supakorn Atchariyawut, Ratana Jiraratananon, Rong WangAbstract:Abstract The objective of this work was to characterize the main mass transfer resistance for CO2 capture in the gas–liquid membrane contacting process by both physical and Chemical Absorption conditions. The characterization was performed based on the resistance-in-series model as well as the Wilson-plot method. In addition, a multistage cascade model, which is able to predict the time for the system to reach a steady-state condition, was developed to describe CO2 Absorption in the membrane contacting process. The cascade model was numerically solved by using the MATLAB program. It was found that the main mass transfer resistance of the physical Absorption (using pure water as an absorbent) and the Chemical Absorption (using 2 M NaOH as an absorbent) was in the liquid phase and in the membrane, respectively. The membrane mass transfer resistance in the case of physical Absorption presented approximately 36% of the total resistances at a liquid velocity of 2.13 m/s. For the Chemical Absorption condition applied, the membrane mass transfer resistance occupied around 99% of the total resistance. The results of simulation by the cascade model agreed well with the experimental results when the overall mass transfer coefficient obtained form the experiment was employed. The model can potentially be used with various operating conditions including the liquid velocity, gas concentration, and reactive absorbent used.