Renewable energy generation,as part of the global effort to mitigate climate change,will play a central role in reducing greenhouse gas emissions and achieving China's goal of carbon emissions peak before 2030 and...Renewable energy generation,as part of the global effort to mitigate climate change,will play a central role in reducing greenhouse gas emissions and achieving China's goal of carbon emissions peak before 2030 and carbon neutral before 2060.However,the impact of carbon quota auctions on renewable energy generation has not been sufficiently discussed.The main purpose of this study is to investigate whether China can rely on quota auctions to increase renewable energy generation in the short term,and to demonstrate which is more effective in promoting renewable energy development,policy enforcement or auction constraints?The improved neo-trans-log production model,the multiobjective linear programming model and the dispatch heuristic were used to predict additional emission reduction cost,optimized power mix with different auctioning rates,with economic development,technological progress and the unique characteristics of China's power generation industry being taken into consideration.The results show that the auctioning rate will have little influence on the optimized energy production structure,especially on the share of renewable energy resources;when the total on-grid electricity generation ranges from 7625 to 7926 billion kW h and the auctioning rate ranges from 0% to 5%,policy enforcement will influence the generation of renewable energy to a greater extent than auctioning in the near future.展开更多
Polyhydroxyalkanoates(PHA)have been produced by some bacteria as bioplastics for many years.Yet their commercialization is still on the way.A few issues are related to the difficulty of PHA commercialization:namely,hi...Polyhydroxyalkanoates(PHA)have been produced by some bacteria as bioplastics for many years.Yet their commercialization is still on the way.A few issues are related to the difficulty of PHA commercialization:namely,high cost and instabilities on molecular weights(Mw)and structures,thus instability on thermo-mechanical properties.The high cost is the result of complicated bioprocessing associated with sterilization,low conversion of carbon substrates to PHA products,and slow growth of microorganisms as well as difficulty of downstream separation.Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles,developments of engineering approaches for the extremophiles,increase on carbon substrates to PHA conversion and controlling Mw of PHA.The concept proof studies could still be conducted on E.coli or Pseudomonas spp.that are easily used for molecular manipulations.In this review,we will use E.coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.展开更多
基金This research was supported by the Natiorml Natural Scicnce Foundation of China(71673086).
文摘Renewable energy generation,as part of the global effort to mitigate climate change,will play a central role in reducing greenhouse gas emissions and achieving China's goal of carbon emissions peak before 2030 and carbon neutral before 2060.However,the impact of carbon quota auctions on renewable energy generation has not been sufficiently discussed.The main purpose of this study is to investigate whether China can rely on quota auctions to increase renewable energy generation in the short term,and to demonstrate which is more effective in promoting renewable energy development,policy enforcement or auction constraints?The improved neo-trans-log production model,the multiobjective linear programming model and the dispatch heuristic were used to predict additional emission reduction cost,optimized power mix with different auctioning rates,with economic development,technological progress and the unique characteristics of China's power generation industry being taken into consideration.The results show that the auctioning rate will have little influence on the optimized energy production structure,especially on the share of renewable energy resources;when the total on-grid electricity generation ranges from 7625 to 7926 billion kW h and the auctioning rate ranges from 0% to 5%,policy enforcement will influence the generation of renewable energy to a greater extent than auctioning in the near future.
基金This research was financially supported by a grant from Ministry of Sciences and Technology(Grant No.2016YFB0302504)grants from National Natural Science Foundation of China(Grant No.31430003)Tsinghua President Fund also supported this project(Grant No.2015THZ10).
文摘Polyhydroxyalkanoates(PHA)have been produced by some bacteria as bioplastics for many years.Yet their commercialization is still on the way.A few issues are related to the difficulty of PHA commercialization:namely,high cost and instabilities on molecular weights(Mw)and structures,thus instability on thermo-mechanical properties.The high cost is the result of complicated bioprocessing associated with sterilization,low conversion of carbon substrates to PHA products,and slow growth of microorganisms as well as difficulty of downstream separation.Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles,developments of engineering approaches for the extremophiles,increase on carbon substrates to PHA conversion and controlling Mw of PHA.The concept proof studies could still be conducted on E.coli or Pseudomonas spp.that are easily used for molecular manipulations.In this review,we will use E.coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.
