The Experts below are selected from a list of 105201 Experts worldwide ranked by ideXlab platform
Aiwu Zeng - One of the best experts on this subject based on the ideXlab platform.
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heat integrated triple column pressure swing distillation process with multi recycle streams for the separation of ternary azeotropic mixture of acetonitrile methanol benzene
Separation and Purification Technology, 2019Co-Authors: Qingjun Zhang, Meiling Liu, Aiwu ZengAbstract:Abstract The Steady-State Economics and dynamic controllability of heat-integrated triple-column pressure-swing distillation (TCPSD) process are explored by taking the separation of ternary mixture of acetonitrile, methanol and benzene as demonstrating example. The performance evaluation indicators of second-law efficiency and CO2 emissions are employed to rank different arrangements except only reference of total annual cost (TAC). Compared to the conventional process, the economically optimum flowsheets are the partially heat-integrated processes (Cases 1 and 2) since it can reduce about 20.00% in TAC, 35.19% in energy-saving and enhancement of 48.77% in thermodynamic efficiency. Dynamic control of the economic efficient processes are also investigated. A series of control structures are developed and assessed by the throughput and feed composition disturbances, which are divided to two categories including control schemes with or without split ratio of the distillate stream of second column. The snowballing effect is efficiently attenuated by control schemes (CS4 and CS5) with the ratio strategy to adjust the recycle stream flowrate for partial Case 1. These control strategies are also applied to partial Case 2, the stable regulatory control is achieved, yet oscillation phenomena for the response of condenser heat removal of second column exists for control strategies without split ratio scheme, while it is efficiently handled by the split ratio scheme coupling with pressure compensated temperature-composition cascade control strategy.
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heat integrated pressure swing distillation process for separation of the maximum boiling azeotrope diethylamine and methanol
Journal of The Taiwan Institute of Chemical Engineers, 2018Co-Authors: Qingjun Zhang, Chenxiaodong Li, Aiwu ZengAbstract:Abstract The Steady-State Economics and dynamic controllability of heat-integrated pressure-swing distillation (PSD) processes are explored by taking the separation of maximum-boiling azeotrope diethylamine and methanol as demonstrating example. Compared to the conventional process, the B-E configuration (hot stream preheating the feed of high-pressure column) is attractive than others due to reducing 36.83% in energy consumption, 20.49% in CO2 emissions and 25.69% in total annual cost (TAC) and enhancing 49.48% in thermodynamic efficiency, respectively. Dynamic controllability of the economic efficient backward-integrated processes is also investigated by teaching the terminology of “simultaneous design”. The effectiveness of single-end control strategy is determined by the method of feed composition sensitive analysis, and a series of control structures are devised and assessed by the perturbations of feed flowrate and composition. The robust control scheme (CS5) with the ratio strategy to manipulate recycle stream flowrate is constructed to eliminate snowball effect and oscillation phenomena for partially case. It is also used to the combinational heat-integrated processes, and the differences of integral absolute error (IAE) are small between the alternative arrangements, demonstrating that the performance of single-end control scheme with the feedforward strategy of molar ratio reflux-to-feed (R/F) is robust and efficient.
Qingjun Zhang - One of the best experts on this subject based on the ideXlab platform.
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heat integrated triple column pressure swing distillation process with multi recycle streams for the separation of ternary azeotropic mixture of acetonitrile methanol benzene
Separation and Purification Technology, 2019Co-Authors: Qingjun Zhang, Meiling Liu, Aiwu ZengAbstract:Abstract The Steady-State Economics and dynamic controllability of heat-integrated triple-column pressure-swing distillation (TCPSD) process are explored by taking the separation of ternary mixture of acetonitrile, methanol and benzene as demonstrating example. The performance evaluation indicators of second-law efficiency and CO2 emissions are employed to rank different arrangements except only reference of total annual cost (TAC). Compared to the conventional process, the economically optimum flowsheets are the partially heat-integrated processes (Cases 1 and 2) since it can reduce about 20.00% in TAC, 35.19% in energy-saving and enhancement of 48.77% in thermodynamic efficiency. Dynamic control of the economic efficient processes are also investigated. A series of control structures are developed and assessed by the throughput and feed composition disturbances, which are divided to two categories including control schemes with or without split ratio of the distillate stream of second column. The snowballing effect is efficiently attenuated by control schemes (CS4 and CS5) with the ratio strategy to adjust the recycle stream flowrate for partial Case 1. These control strategies are also applied to partial Case 2, the stable regulatory control is achieved, yet oscillation phenomena for the response of condenser heat removal of second column exists for control strategies without split ratio scheme, while it is efficiently handled by the split ratio scheme coupling with pressure compensated temperature-composition cascade control strategy.
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heat integrated pressure swing distillation process for separation of the maximum boiling azeotrope diethylamine and methanol
Journal of The Taiwan Institute of Chemical Engineers, 2018Co-Authors: Qingjun Zhang, Chenxiaodong Li, Aiwu ZengAbstract:Abstract The Steady-State Economics and dynamic controllability of heat-integrated pressure-swing distillation (PSD) processes are explored by taking the separation of maximum-boiling azeotrope diethylamine and methanol as demonstrating example. Compared to the conventional process, the B-E configuration (hot stream preheating the feed of high-pressure column) is attractive than others due to reducing 36.83% in energy consumption, 20.49% in CO2 emissions and 25.69% in total annual cost (TAC) and enhancing 49.48% in thermodynamic efficiency, respectively. Dynamic controllability of the economic efficient backward-integrated processes is also investigated by teaching the terminology of “simultaneous design”. The effectiveness of single-end control strategy is determined by the method of feed composition sensitive analysis, and a series of control structures are devised and assessed by the perturbations of feed flowrate and composition. The robust control scheme (CS5) with the ratio strategy to manipulate recycle stream flowrate is constructed to eliminate snowball effect and oscillation phenomena for partially case. It is also used to the combinational heat-integrated processes, and the differences of integral absolute error (IAE) are small between the alternative arrangements, demonstrating that the performance of single-end control scheme with the feedforward strategy of molar ratio reflux-to-feed (R/F) is robust and efficient.
Elke Pirgmaier - One of the best experts on this subject based on the ideXlab platform.
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the neoclassical trojan horse of steady state Economics
Ecological Economics, 2017Co-Authors: Elke PirgmaierAbstract:The vision of a Steady-State economy elaborated by Herman Daly describes an economy that uses materials and energy within the regenerative and assimilative limits of the planet's ecosystems. Sustainable scale, just distribution, and efficient allocation are its constitutive theoretical goals. This paper is a critique of the theoretical foundations of Steady-State Economics. It argues that Steady-State Economics consists in an attempt to squeeze neoclassical Economics into a biophysical and ethical corset. As a result, many fundamental flaws and criticisms of neoclassical Economics remain. As a consequence, Steady-State Economics does not lead to a radical departure from, or improvement upon, neoclassical theory but rather to fundamental internal inconsistencies between the ‘old’ Economics paradigm and ‘new’ progressive ecological economic thinking. Contradictions appear at various levels ranging from ontology and methodology to theory and values. As Daly has pioneered the foundations of ecological Economics with his thinking, these ambiguities are not only problematic for Steady-State Economics but ecological Economics as a field more generally. The paper concludes that ecological Economics has to let go of neoclassical foundations as they contradict its core values and ambitions. A new and consistent theory of political economy of the environment along heterodox lines is needed.
Meiling Liu - One of the best experts on this subject based on the ideXlab platform.
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heat integrated triple column pressure swing distillation process with multi recycle streams for the separation of ternary azeotropic mixture of acetonitrile methanol benzene
Separation and Purification Technology, 2019Co-Authors: Qingjun Zhang, Meiling Liu, Aiwu ZengAbstract:Abstract The Steady-State Economics and dynamic controllability of heat-integrated triple-column pressure-swing distillation (TCPSD) process are explored by taking the separation of ternary mixture of acetonitrile, methanol and benzene as demonstrating example. The performance evaluation indicators of second-law efficiency and CO2 emissions are employed to rank different arrangements except only reference of total annual cost (TAC). Compared to the conventional process, the economically optimum flowsheets are the partially heat-integrated processes (Cases 1 and 2) since it can reduce about 20.00% in TAC, 35.19% in energy-saving and enhancement of 48.77% in thermodynamic efficiency. Dynamic control of the economic efficient processes are also investigated. A series of control structures are developed and assessed by the throughput and feed composition disturbances, which are divided to two categories including control schemes with or without split ratio of the distillate stream of second column. The snowballing effect is efficiently attenuated by control schemes (CS4 and CS5) with the ratio strategy to adjust the recycle stream flowrate for partial Case 1. These control strategies are also applied to partial Case 2, the stable regulatory control is achieved, yet oscillation phenomena for the response of condenser heat removal of second column exists for control strategies without split ratio scheme, while it is efficiently handled by the split ratio scheme coupling with pressure compensated temperature-composition cascade control strategy.
Chenxiaodong Li - One of the best experts on this subject based on the ideXlab platform.
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heat integrated pressure swing distillation process for separation of the maximum boiling azeotrope diethylamine and methanol
Journal of The Taiwan Institute of Chemical Engineers, 2018Co-Authors: Qingjun Zhang, Chenxiaodong Li, Aiwu ZengAbstract:Abstract The Steady-State Economics and dynamic controllability of heat-integrated pressure-swing distillation (PSD) processes are explored by taking the separation of maximum-boiling azeotrope diethylamine and methanol as demonstrating example. Compared to the conventional process, the B-E configuration (hot stream preheating the feed of high-pressure column) is attractive than others due to reducing 36.83% in energy consumption, 20.49% in CO2 emissions and 25.69% in total annual cost (TAC) and enhancing 49.48% in thermodynamic efficiency, respectively. Dynamic controllability of the economic efficient backward-integrated processes is also investigated by teaching the terminology of “simultaneous design”. The effectiveness of single-end control strategy is determined by the method of feed composition sensitive analysis, and a series of control structures are devised and assessed by the perturbations of feed flowrate and composition. The robust control scheme (CS5) with the ratio strategy to manipulate recycle stream flowrate is constructed to eliminate snowball effect and oscillation phenomena for partially case. It is also used to the combinational heat-integrated processes, and the differences of integral absolute error (IAE) are small between the alternative arrangements, demonstrating that the performance of single-end control scheme with the feedforward strategy of molar ratio reflux-to-feed (R/F) is robust and efficient.