A large amount of waste liquids containing methanol/acetone/water mixtures are produced in the synthesis of methyl methacrylate(MMA).Under the advocacy of green chemical industry,it is urgent to develop an efficient,e...A large amount of waste liquids containing methanol/acetone/water mixtures are produced in the synthesis of methyl methacrylate(MMA).Under the advocacy of green chemical industry,it is urgent to develop an efficient,economic and energy-saving mixture separation process.Through thermodynamic azeotropic behavior and pressure sensitivity analysis,pressure-swing distillation was determined and the optimal separation pressure of each column in the process was obtained.Due to the composition of waste liquids produced were quite different in MMA production,the pressure-swing distillation separation process was designed to fully achieve the accurate waste liquids treatment.Taking the total annual cost(TAC)as the target,the sequential iteration method was used to optimize the process,and the impact of composition on economy was compared.In order to further realize the energy-saving of the separation process,the pervaporation membrane module was introduced to pretreat the waste liquid in the pressure-swing distillation.The results showed that the TAC of the coupling process was 46% higher than that of the pressure-swing distillation process,and the thermodynamic efficiency was 30% higher.This study provides waste liquid treatment technology for enterprises and analyzes its economic and energy efficiency,which has reference significance for the development of coupled separation technology.展开更多
This paper argues that major powers can play critical roles in a complicated regime system,as evidenced by China and the U.S.which have had pivotal influence in the construction of the post-2020 climate regime.China a...This paper argues that major powers can play critical roles in a complicated regime system,as evidenced by China and the U.S.which have had pivotal influence in the construction of the post-2020 climate regime.China and the U.S.have participated in multilateral consultations beyond the scope of the United Nations Framework Convention on Climate Change(UNFCCC)while making use of many political platforms,such as Asia-Pacific Economic Cooperation(APEC),G20,and informal meetings and dialogues to bridge the gap among various approaches to mitigating climate impacts.China-U.S.bilateral cooperation has incorporated energy and climate issues into the strategic and economic dialogue(S&ED)and launched other schemes,such as EcoPartnerships and wide-ranging dialogues and initiatives on clean energy/clean vehicles.These schemes support the reconciliation of ideas related to domestic abatement policies in the areas of energy,climate change,and environmental protection.Since the Trump administration came to power in 2017,the bilateral cooperation at national level has been retreated significantly and therefore slowdown the UN’s institutional response to climate change.At the stage,the U.S.may not be able to play a critical role in shaping the regime,yet China is regarded to be the most important player in negotiations under the Paris Agreement.展开更多
According to the analysis results of risk,economy and practical experiences for many years,the paper demonstrates that the great economic benifits can be got by reducing the design flood standard of energy dissipators...According to the analysis results of risk,economy and practical experiences for many years,the paper demonstrates that the great economic benifits can be got by reducing the design flood standard of energy dissipators and that the reduction of design flood standard is significant for reducing project investment and speeding project construction.展开更多
基金supported by the National Natural Science Foundation of China(22078166)。
文摘A large amount of waste liquids containing methanol/acetone/water mixtures are produced in the synthesis of methyl methacrylate(MMA).Under the advocacy of green chemical industry,it is urgent to develop an efficient,economic and energy-saving mixture separation process.Through thermodynamic azeotropic behavior and pressure sensitivity analysis,pressure-swing distillation was determined and the optimal separation pressure of each column in the process was obtained.Due to the composition of waste liquids produced were quite different in MMA production,the pressure-swing distillation separation process was designed to fully achieve the accurate waste liquids treatment.Taking the total annual cost(TAC)as the target,the sequential iteration method was used to optimize the process,and the impact of composition on economy was compared.In order to further realize the energy-saving of the separation process,the pervaporation membrane module was introduced to pretreat the waste liquid in the pressure-swing distillation.The results showed that the TAC of the coupling process was 46% higher than that of the pressure-swing distillation process,and the thermodynamic efficiency was 30% higher.This study provides waste liquid treatment technology for enterprises and analyzes its economic and energy efficiency,which has reference significance for the development of coupled separation technology.
基金This work was supported by IDE-JETRO research project,and JSPS KAKENHI Grant-in-Aid for Young Scientists(B)Number 16K17077.
文摘This paper argues that major powers can play critical roles in a complicated regime system,as evidenced by China and the U.S.which have had pivotal influence in the construction of the post-2020 climate regime.China and the U.S.have participated in multilateral consultations beyond the scope of the United Nations Framework Convention on Climate Change(UNFCCC)while making use of many political platforms,such as Asia-Pacific Economic Cooperation(APEC),G20,and informal meetings and dialogues to bridge the gap among various approaches to mitigating climate impacts.China-U.S.bilateral cooperation has incorporated energy and climate issues into the strategic and economic dialogue(S&ED)and launched other schemes,such as EcoPartnerships and wide-ranging dialogues and initiatives on clean energy/clean vehicles.These schemes support the reconciliation of ideas related to domestic abatement policies in the areas of energy,climate change,and environmental protection.Since the Trump administration came to power in 2017,the bilateral cooperation at national level has been retreated significantly and therefore slowdown the UN’s institutional response to climate change.At the stage,the U.S.may not be able to play a critical role in shaping the regime,yet China is regarded to be the most important player in negotiations under the Paris Agreement.
文摘According to the analysis results of risk,economy and practical experiences for many years,the paper demonstrates that the great economic benifits can be got by reducing the design flood standard of energy dissipators and that the reduction of design flood standard is significant for reducing project investment and speeding project construction.
