Yihang Yue, Zexu Yu, Xiaoju Yue, Wentao Zhou, Saiyu Wang, Yanxi Yang, Youliang Lao, Mengdi Yang, C. Du, Shifeng Wang
Biomass activated carbon has been widely used in the field of wastewater treatment because of its unique properties, such as high specific surface area and porosity, good adsorption capacity, good mechanical strength, rich functional groups and thermal stability. In this work, highland barley straw is recycled and made into activated carbon using hydrothermal carbonization and alkaline activation processes in which the dependence of the product properties on the activation temperature, as one of the critical parameters, is intensively investigated. Under the optimum conditions at an activation temperature of 1100 °C, activated carbon in the form of mesoporous structure and polycrystalline graphite was produced with a specific surface area as large as 1906 m2/g, which is superior to that of commercial products. To investigate the absorption capacity of the prepared samples for pollutants in water, such as heavy metals and organics, potassium dichromate and methylene blue were utilized as the simulated pollutants. The removal efficiency of Cr6+ and methylene blue in water reached 90.3 % within eight hours and 87.7 % within four hours, respectively, and this demonstrated an excellent absorption capacity for activated carbon converted from agricultural waste. Th e successful fabrication of activated carbon with a super large specific surface area and remarkable adsorption ability derived from highland barley straw through a hydrothermal carbonization and alkaline treatment demonstrated the feasibility of the “turning waste into wealth” recycling strategy. It has also shown great potential for use in environmental protection applications, especially for water purification.
{"title":"Activated carbon derived from highland barley straw for removing heavy metals and organic pollutants","authors":"Yihang Yue, Zexu Yu, Xiaoju Yue, Wentao Zhou, Saiyu Wang, Yanxi Yang, Youliang Lao, Mengdi Yang, C. Du, Shifeng Wang","doi":"10.1093/ijlct/ctad042","DOIUrl":"https://doi.org/10.1093/ijlct/ctad042","url":null,"abstract":"\u0000 Biomass activated carbon has been widely used in the field of wastewater treatment because of its unique properties, such as high specific surface area and porosity, good adsorption capacity, good mechanical strength, rich functional groups and thermal stability. In this work, highland barley straw is recycled and made into activated carbon using hydrothermal carbonization and alkaline activation processes in which the dependence of the product properties on the activation temperature, as one of the critical parameters, is intensively investigated. Under the optimum conditions at an activation temperature of 1100 °C, activated carbon in the form of mesoporous structure and polycrystalline graphite was produced with a specific surface area as large as 1906 m2/g, which is superior to that of commercial products. To investigate the absorption capacity of the prepared samples for pollutants in water, such as heavy metals and organics, potassium dichromate and methylene blue were utilized as the simulated pollutants. The removal efficiency of Cr6+ and methylene blue in water reached 90.3 % within eight hours and 87.7 % within four hours, respectively, and this demonstrated an excellent absorption capacity for activated carbon converted from agricultural waste. Th e successful fabrication of activated carbon with a super large specific surface area and remarkable adsorption ability derived from highland barley straw through a hydrothermal carbonization and alkaline treatment demonstrated the feasibility of the “turning waste into wealth” recycling strategy. It has also shown great potential for use in environmental protection applications, especially for water purification.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43738372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Alla, L. Bammou, S. Alami, M. Najim, A. Charef, Said Bouchta, M. Errai, M. Feddaoui
The need for freshwater supply in different parts of the world has given great interest to the study of seawater desalination which has led to the development of various innovative techniques in this field. The present numerical study contributes to the improvement of the evaporative desalination operation by introducing nanoparticles into the base fluid. The desalination technique considered in this study consists of a saltwater film falling along the inner wall of a vertical channel heated uniformly by a constant heat flux. The equations governing the flow and the heat and mass transfer associated with the boundary and interface conditions are solved numerically using the finite difference method. We considered two values of salinity, 10 g.kg-1 and 39 g.kg-1 which correspond respectively to brackish water and sea water with different types and volume fractions of nanoparticles in order to study the effect of the combination of these parameters on the enhancement of desalination by evaporation. The results showed that the evaporation process by injecting nanoparticles into salt water improves due to its positive effect on thermophysical properties. In addition, Al2O3 is significantly better for evaporative desalination than TiO2 and copper. Moreover, we can achieve the same heat and mass transfer performance by using 2% alumina instead of 4% TiO2.
{"title":"Effect of nanoparticles on the evaporation of a salt water film.","authors":"A. Alla, L. Bammou, S. Alami, M. Najim, A. Charef, Said Bouchta, M. Errai, M. Feddaoui","doi":"10.1093/ijlct/ctad035","DOIUrl":"https://doi.org/10.1093/ijlct/ctad035","url":null,"abstract":"\u0000 The need for freshwater supply in different parts of the world has given great interest to the study of seawater desalination which has led to the development of various innovative techniques in this field. The present numerical study contributes to the improvement of the evaporative desalination operation by introducing nanoparticles into the base fluid. The desalination technique considered in this study consists of a saltwater film falling along the inner wall of a vertical channel heated uniformly by a constant heat flux. The equations governing the flow and the heat and mass transfer associated with the boundary and interface conditions are solved numerically using the finite difference method. We considered two values of salinity, 10 g.kg-1 and 39 g.kg-1 which correspond respectively to brackish water and sea water with different types and volume fractions of nanoparticles in order to study the effect of the combination of these parameters on the enhancement of desalination by evaporation. The results showed that the evaporation process by injecting nanoparticles into salt water improves due to its positive effect on thermophysical properties. In addition, Al2O3 is significantly better for evaporative desalination than TiO2 and copper. Moreover, we can achieve the same heat and mass transfer performance by using 2% alumina instead of 4% TiO2.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44175174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kilanko Oluwaseun, O. O. Sunday, Dirisu O. Joseph, Leramo O Richard, Babalola O Philip, Aworinde K Abraham, Udo Mfon, Okonkwo M Alexander, Akomolafe I Marvellous, Saleh Bahaa
In this study, the Typical Meteorological Year (TMY) data for six locations representing the 6 geo-political zones in Nigeria were generated and analyzed using the Sandia Method. The analysis shows that seasonal variations exist in all the selected locations indicating two distinct seasons: the dry and wet seasons with varying lengths from north to south of the country. Due to its high global radiation levels (21–25 MJ/m2/day), the North is a desirable location for solar-thermal systems. Also, the high monthly mean temperature variations (about 18°C), low relative humidity (15%) and constant wind speeds (4m/s) experienced in the first three months of the year aid the installation of wind energy systems and the application of evaporative cooling techniques that reduce the thermal load and energy consumption of buildings. On the other side, the high relative humidity (80%) and mediocre radiation values derived almost throughout the year in the South-west, South-east and South-south regions discourages the extensive application of evaporative cooling and solar energy based systems in such locations, but the moderate wind speeds (2.9 m/s) and monthly mean temperature variations associated with these regions between the first three months of the year allow for the application of natural ventilation and some passive cooling systems so as to reduce the thermal load of buildings in the regions. The information presented in this work can serve as a guide for design and selection of energy systems and application of energy-related projects in Nigeria.
{"title":"Typical Meteorological Year Data Analysis for Optimal Utilization of Energy Systems at Six Selected Locations in Nigeria","authors":"Kilanko Oluwaseun, O. O. Sunday, Dirisu O. Joseph, Leramo O Richard, Babalola O Philip, Aworinde K Abraham, Udo Mfon, Okonkwo M Alexander, Akomolafe I Marvellous, Saleh Bahaa","doi":"10.1093/ijlct/ctad014","DOIUrl":"https://doi.org/10.1093/ijlct/ctad014","url":null,"abstract":"\u0000 In this study, the Typical Meteorological Year (TMY) data for six locations representing the 6 geo-political zones in Nigeria were generated and analyzed using the Sandia Method. The analysis shows that seasonal variations exist in all the selected locations indicating two distinct seasons: the dry and wet seasons with varying lengths from north to south of the country. Due to its high global radiation levels (21–25 MJ/m2/day), the North is a desirable location for solar-thermal systems. Also, the high monthly mean temperature variations (about 18°C), low relative humidity (15%) and constant wind speeds (4m/s) experienced in the first three months of the year aid the installation of wind energy systems and the application of evaporative cooling techniques that reduce the thermal load and energy consumption of buildings. On the other side, the high relative humidity (80%) and mediocre radiation values derived almost throughout the year in the South-west, South-east and South-south regions discourages the extensive application of evaporative cooling and solar energy based systems in such locations, but the moderate wind speeds (2.9 m/s) and monthly mean temperature variations associated with these regions between the first three months of the year allow for the application of natural ventilation and some passive cooling systems so as to reduce the thermal load of buildings in the regions. The information presented in this work can serve as a guide for design and selection of energy systems and application of energy-related projects in Nigeria.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45419436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rahul Velanparambil Ravindran, M. Huang, N. Hewitt
Organic Rankine cycle (ORC) and heat pump (HP) are two well-established technologies for industrial waste heat recovery. Given the similarity between ORC and HP configurations, a system that can switch between HP and ORC modes with minimal modification is feasible. The reversible system according to the requirement of the industry can exploit waste heat in lower temperature bands operating as a high-temperature heat pump (HTHP) to provide useful process heat or as an organic Rankine cycle system generating power and thus increasing the efficiency of waste heat exploitation. This study discusses the design aspects of a small-scale reversible HTHP - ORC system, including the system layout, component selection, selection of an appropriate working fluid, the operating conditions for both modes, and equipment sizing. R1233zd(E) was selected as the refrigerant for the reversible system and an automotive open drive scroll compressor was found to be suitable which can also be employed as an expander for ORC with minimum modifications. The study also presents the modelling of the reversible system in ORC and HTHP modes including performance analysis of scroll machine in expander and compressor roles attaining isentropic efficiency values up to 62.4% and 75.4% respectively. The modelling results show a cycle efficiency of 5.9% (Tev = 102 °C, ṁr = 0.064 kg/s) in ORC mode and a COP of 4.19 in HTHP mode (for a temperature lift of 49 K with Tsource: 85 °C, Ncomp: 2000 RPM).
{"title":"Design and modelling of a small-scale reversible high temperature heat pump – organic Rankine cycle system for industrial waste heat recovery","authors":"Rahul Velanparambil Ravindran, M. Huang, N. Hewitt","doi":"10.1093/ijlct/ctad038","DOIUrl":"https://doi.org/10.1093/ijlct/ctad038","url":null,"abstract":"\u0000 Organic Rankine cycle (ORC) and heat pump (HP) are two well-established technologies for industrial waste heat recovery. Given the similarity between ORC and HP configurations, a system that can switch between HP and ORC modes with minimal modification is feasible. The reversible system according to the requirement of the industry can exploit waste heat in lower temperature bands operating as a high-temperature heat pump (HTHP) to provide useful process heat or as an organic Rankine cycle system generating power and thus increasing the efficiency of waste heat exploitation. This study discusses the design aspects of a small-scale reversible HTHP - ORC system, including the system layout, component selection, selection of an appropriate working fluid, the operating conditions for both modes, and equipment sizing. R1233zd(E) was selected as the refrigerant for the reversible system and an automotive open drive scroll compressor was found to be suitable which can also be employed as an expander for ORC with minimum modifications. The study also presents the modelling of the reversible system in ORC and HTHP modes including performance analysis of scroll machine in expander and compressor roles attaining isentropic efficiency values up to 62.4% and 75.4% respectively. The modelling results show a cycle efficiency of 5.9% (Tev = 102 °C, ṁr = 0.064 kg/s) in ORC mode and a COP of 4.19 in HTHP mode (for a temperature lift of 49 K with Tsource: 85 °C, Ncomp: 2000 RPM).","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44658733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Photovoltaic (PV) is one of the very promising renewable energy sources, but its output power is fluctuating. To maintain PV-energy storage system-load power balance in low-voltage distribution networks, we propose a new optimized sag control strategy, which is no longer indexed by the battery voltage but by the battery state of charge (SOC), because the battery SOC can better reflect the remaining battery capacity for better performance. In addition, to further optimize its performance, we try to use the ratio of inter-cell SOC for optimization. We analyzed the deficiencies of sag control in detail, derived a control strategy with cell SOC as an indicator, and finally analyzed its performance in detail. To verify the performance of the proposed strategy, based on MATLAB, we designed the power variation of 2 Lithium-ion battery packs to maintain the bus power stability under two cases of sudden rise as well as sudden fall of PV power, and 3 Lithium-ion battery to maintain during the bus power stabilization with one set of performance after failure, and the simulation results prove the feasibility of the proposed strategy.
{"title":"Optimal control of energy storage system of high-permeability distributed photovoltaic low-voltage distribution network","authors":"Yezhou Yang, Yubo Yuan, Hao Jiao, Jinming Chen, Xianglu Pang, Shuyi Zhuang","doi":"10.1093/ijlct/ctad041","DOIUrl":"https://doi.org/10.1093/ijlct/ctad041","url":null,"abstract":"Photovoltaic (PV) is one of the very promising renewable energy sources, but its output power is fluctuating. To maintain PV-energy storage system-load power balance in low-voltage distribution networks, we propose a new optimized sag control strategy, which is no longer indexed by the battery voltage but by the battery state of charge (SOC), because the battery SOC can better reflect the remaining battery capacity for better performance. In addition, to further optimize its performance, we try to use the ratio of inter-cell SOC for optimization. We analyzed the deficiencies of sag control in detail, derived a control strategy with cell SOC as an indicator, and finally analyzed its performance in detail. To verify the performance of the proposed strategy, based on MATLAB, we designed the power variation of 2 Lithium-ion battery packs to maintain the bus power stability under two cases of sudden rise as well as sudden fall of PV power, and 3 Lithium-ion battery to maintain during the bus power stabilization with one set of performance after failure, and the simulation results prove the feasibility of the proposed strategy.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45140149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Photovoltaic (PV) and wind power generation are very promising renewable energy sources, reasonable capacity allocation of PV-wind complementary energy storage (ES) power generation system can improve the economy and reliability of system operation. In this paper, the goal is to ensure the power supply of the system and reduce the operation cost. The PV, wind and ES system models are analyzed. The differential evolutionary (DE) algorithm is adopted to optimize the particle swarm optimization (PSO) algorithm, and the parameters of the PSO algorithm are changed through the DE algorithm to obtain better performance. We use MATLAB to verify that when the system is composed of 100kW PV and 100kW wind power, the battery capacity obtained by PSO algorithm is 400kWh, while the algorithm proposed in this paper only requires 330kWh. although the loss of load probability of the system is improved by about 0.12%, the cost is saved by 17.5%. To improve the system operation reliability, we recommend increasing PV, wind and ES capacity at the same time rather than increasing ES capacity separately.
{"title":"Capacity optimization strategy for energy storage system to ensure power supply","authors":"H. Fu, Ming Shi, Miaomiao Feng","doi":"10.1093/ijlct/ctad039","DOIUrl":"https://doi.org/10.1093/ijlct/ctad039","url":null,"abstract":"\u0000 Photovoltaic (PV) and wind power generation are very promising renewable energy sources, reasonable capacity allocation of PV-wind complementary energy storage (ES) power generation system can improve the economy and reliability of system operation. In this paper, the goal is to ensure the power supply of the system and reduce the operation cost. The PV, wind and ES system models are analyzed. The differential evolutionary (DE) algorithm is adopted to optimize the particle swarm optimization (PSO) algorithm, and the parameters of the PSO algorithm are changed through the DE algorithm to obtain better performance. We use MATLAB to verify that when the system is composed of 100kW PV and 100kW wind power, the battery capacity obtained by PSO algorithm is 400kWh, while the algorithm proposed in this paper only requires 330kWh. although the loss of load probability of the system is improved by about 0.12%, the cost is saved by 17.5%. To improve the system operation reliability, we recommend increasing PV, wind and ES capacity at the same time rather than increasing ES capacity separately.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45743434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The comprehensive energy system of the park is one of the effective ways to solve the problems of low utilization efficiency of comprehensive energy and difficulty in absorbing renewable energy. By coordinating the output of each unit to optimize the scheduling of the system, the operating cost of the system can be reduced to a certain extent, and the space for new energy generation to be connected to the Internet can be increased. Aiming at the characteristics of electric, heat and gas load demand of the integrated energy system of industrial low-carbon parks and the overall needs of low-carbon development, a research on the optimal scheduling of integrated energy systems in low-carbon parks based on demand response is proposed. By analyzing the structure and components of the integrated energy system of the low-carbon park, different types of demand response are modeled. On this basis, based on the comprehensive demand response of electricity and heat, the optimal dispatch model of the integrated energy system of the low-carbon park is constructed, and the model is solved to realize the optimal dispatch of the integrated energy system of the low-carbon park. The experimental results show that the proposed method has lower operating cost of the integrated energy system, better economy of the integrated energy system, and can effectively improve the power supply reliability and energy saving rate of the integrated energy system. The average system load rate of the proposed method is up to 98.7%, the average comprehensive energy utilization rate is up to 97.9%, and the system operation cost is only 10343.1 yuan.
{"title":"Research on optimal scheduling of integrated energy system in low-carbon parks based on demand response","authors":"Wei Xu, W. Han, Huaizhang Jin, Y. Bai, Huan Liu","doi":"10.1093/ijlct/ctad020","DOIUrl":"https://doi.org/10.1093/ijlct/ctad020","url":null,"abstract":"\u0000 The comprehensive energy system of the park is one of the effective ways to solve the problems of low utilization efficiency of comprehensive energy and difficulty in absorbing renewable energy. By coordinating the output of each unit to optimize the scheduling of the system, the operating cost of the system can be reduced to a certain extent, and the space for new energy generation to be connected to the Internet can be increased. Aiming at the characteristics of electric, heat and gas load demand of the integrated energy system of industrial low-carbon parks and the overall needs of low-carbon development, a research on the optimal scheduling of integrated energy systems in low-carbon parks based on demand response is proposed. By analyzing the structure and components of the integrated energy system of the low-carbon park, different types of demand response are modeled. On this basis, based on the comprehensive demand response of electricity and heat, the optimal dispatch model of the integrated energy system of the low-carbon park is constructed, and the model is solved to realize the optimal dispatch of the integrated energy system of the low-carbon park. The experimental results show that the proposed method has lower operating cost of the integrated energy system, better economy of the integrated energy system, and can effectively improve the power supply reliability and energy saving rate of the integrated energy system. The average system load rate of the proposed method is up to 98.7%, the average comprehensive energy utilization rate is up to 97.9%, and the system operation cost is only 10343.1 yuan.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46762418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Currently, realizing the coordinated green development of the economy and environment has become the focus of all walks of life. To achieve this goal, it is important for cities to promote carbon reduction. China has implemented a low-carbon city pilot (LCP) policy since 2010 to achieve green transformative development. In this context, this study aims to assess whether the LCP policy achieves carbon peaking and carbon neutrality goals. Using 2007-2019 prefecture-level panel data from China and a time-varying difference-in-difference (DID) model, we conduct a quasi-natural experiment. The empirical results show that the carbon emission intensity (CEI) is greatly reduced in cities that implemented the LCP policy. Compared with the control group, the average value of CEI of cities in the experimental group is approximately three percentage points lower, and the robustness test results prove the reliability of the baseline estimates. In addition, we examine the time lag effect and find that in the experimental group, the CEI of cities is significantly lower in the fourth year and has a tendency to gradually increase. Meanwhile, the heterogeneity analysis in this research groups the samples according to economic development, population agglomeration and resource endowment. We find that in cities with better economic development, higher population agglomeration and relatively underdeveloped resource endowment, there is a greater reduction in CEI. Finally, we conduct a mechanism test and find that in the experimental group, the CEI of cities is severely reduced due to industrial structure optimization, environmental enforcement strengthening and technological innovation capabilities enhancement.
{"title":"Does the Low-Carbon Construction of Cities in China Reduce Carbon Emission Intensity?","authors":"Chengkang He, Cheng Shu, Jinlang Zou, Yunliang Li","doi":"10.1093/ijlct/ctac131","DOIUrl":"https://doi.org/10.1093/ijlct/ctac131","url":null,"abstract":"\u0000 Currently, realizing the coordinated green development of the economy and environment has become the focus of all walks of life. To achieve this goal, it is important for cities to promote carbon reduction. China has implemented a low-carbon city pilot (LCP) policy since 2010 to achieve green transformative development. In this context, this study aims to assess whether the LCP policy achieves carbon peaking and carbon neutrality goals. Using 2007-2019 prefecture-level panel data from China and a time-varying difference-in-difference (DID) model, we conduct a quasi-natural experiment. The empirical results show that the carbon emission intensity (CEI) is greatly reduced in cities that implemented the LCP policy. Compared with the control group, the average value of CEI of cities in the experimental group is approximately three percentage points lower, and the robustness test results prove the reliability of the baseline estimates. In addition, we examine the time lag effect and find that in the experimental group, the CEI of cities is significantly lower in the fourth year and has a tendency to gradually increase. Meanwhile, the heterogeneity analysis in this research groups the samples according to economic development, population agglomeration and resource endowment. We find that in cities with better economic development, higher population agglomeration and relatively underdeveloped resource endowment, there is a greater reduction in CEI. Finally, we conduct a mechanism test and find that in the experimental group, the CEI of cities is severely reduced due to industrial structure optimization, environmental enforcement strengthening and technological innovation capabilities enhancement.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48589525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing low-carbon economy is an inherent requirement for China's sustainable development, and digital economy is an important engine for China's economy to reduce carbon emission intensity in the new development stage. Identifying the industrial evolution law of China's digital economy is helpful to diagnose its development opportunity, tap the "green potential", and provide strategic support for the digital economy to play the low-carbon effect. Based on the data of China's digital industrialization and industry digitization from 2001 to 2020, the development level of China's digital economy industry was analyzed by Logistic curve estimation, and the evolution stage of China's digital economy industry was determined by the characteristic points of the curve. The results showed that, before 2008, China's digital economy industry was in the germination period; from 2009 to 2035, China's digital economy industry is in the period of accelerating growth; from 2036-2062, China's digital economy industry will be in the mature stage; after 2062, it will enter a period of decline. The above analysis results are basically in line with the requirements of China's "strategic plan to become a high-income country by 2035" and "strategic goal of achieving carbon neutrality by 2060". Finally, according to the carbon emission reduction development demand of China's digital economy in the "growth period", it is pointed out that it is urgent for China to continue to promote the construction of digital infrastructure, achieve green digital technology innovation, improve the social digital literacy level and increase the proportion of renewable energy application.
{"title":"Stage identification and strategy optimization of industrial evolution of China's digital economy supporting low-carbon effect","authors":"Yanping Yang, Bojun Wang","doi":"10.1093/ijlct/ctad007","DOIUrl":"https://doi.org/10.1093/ijlct/ctad007","url":null,"abstract":"\u0000 Developing low-carbon economy is an inherent requirement for China's sustainable development, and digital economy is an important engine for China's economy to reduce carbon emission intensity in the new development stage. Identifying the industrial evolution law of China's digital economy is helpful to diagnose its development opportunity, tap the \"green potential\", and provide strategic support for the digital economy to play the low-carbon effect. Based on the data of China's digital industrialization and industry digitization from 2001 to 2020, the development level of China's digital economy industry was analyzed by Logistic curve estimation, and the evolution stage of China's digital economy industry was determined by the characteristic points of the curve. The results showed that, before 2008, China's digital economy industry was in the germination period; from 2009 to 2035, China's digital economy industry is in the period of accelerating growth; from 2036-2062, China's digital economy industry will be in the mature stage; after 2062, it will enter a period of decline. The above analysis results are basically in line with the requirements of China's \"strategic plan to become a high-income country by 2035\" and \"strategic goal of achieving carbon neutrality by 2060\". Finally, according to the carbon emission reduction development demand of China's digital economy in the \"growth period\", it is pointed out that it is urgent for China to continue to promote the construction of digital infrastructure, achieve green digital technology innovation, improve the social digital literacy level and increase the proportion of renewable energy application.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41944793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A competitive advantage for the molten carbonate fuel cell (MCFC)-driven energy processes is their fuel versatility. On the other hand, since MCFC consumes carbon dioxide, it can reduce the amount of carbon dioxide emissions compared to other fuel cells. Accordingly, the current paper develops and evaluates the thermodynamic, exergoeconomic and environmental analysis of a new hybrid energy process (HEP) based on a reformer MCFC stack and a biomass gasification process. A homogeneous ignition engine (HIE) and a heat recovery system are two other main units embedded in the developed HEP. In the developed cycle, MCFC and HIE produce electric energy, for which the required fuel is supplied through the obtained syngas from the biomass gasification process and the anode off-gas, respectively. The heat recovery system also leads to the establishment of the thermal balance of the energy cycle by recovering the thermal energies of the MCFC and HIE. The aim of the present work is to develop the multi-aspect evaluation of the proposed energy system toward a fruitful implementation feasibility analysis. The outcomes indicated that, the rates of electrical and thermal powers obtained from the planned HEP were equal to nearly 1112 kW and 367 kW, respectively. Further, the calculated efficiencies for electric, gross power and total energy terms were equal to 51.5%, 55.7%, and 69.9%, respectively. The developed HEP had 48% less carbon dioxide emissions compared to an petroleum-fired power plant, 15.8% less compared to a natural gas-fired plant, and approximately 63% lower compared to a coal-fired power plant.
{"title":"Evaluation of carbon dioxide emission reduction in an energy cycle based on biomass gasification and molten carbonate fuel cell; Exergoeconomic and environmental analysis","authors":"Di Zhang, Te Ma, H. Fooladi","doi":"10.1093/ijlct/ctad006","DOIUrl":"https://doi.org/10.1093/ijlct/ctad006","url":null,"abstract":"\u0000 A competitive advantage for the molten carbonate fuel cell (MCFC)-driven energy processes is their fuel versatility. On the other hand, since MCFC consumes carbon dioxide, it can reduce the amount of carbon dioxide emissions compared to other fuel cells. Accordingly, the current paper develops and evaluates the thermodynamic, exergoeconomic and environmental analysis of a new hybrid energy process (HEP) based on a reformer MCFC stack and a biomass gasification process. A homogeneous ignition engine (HIE) and a heat recovery system are two other main units embedded in the developed HEP. In the developed cycle, MCFC and HIE produce electric energy, for which the required fuel is supplied through the obtained syngas from the biomass gasification process and the anode off-gas, respectively. The heat recovery system also leads to the establishment of the thermal balance of the energy cycle by recovering the thermal energies of the MCFC and HIE. The aim of the present work is to develop the multi-aspect evaluation of the proposed energy system toward a fruitful implementation feasibility analysis. The outcomes indicated that, the rates of electrical and thermal powers obtained from the planned HEP were equal to nearly 1112 kW and 367 kW, respectively. Further, the calculated efficiencies for electric, gross power and total energy terms were equal to 51.5%, 55.7%, and 69.9%, respectively. The developed HEP had 48% less carbon dioxide emissions compared to an petroleum-fired power plant, 15.8% less compared to a natural gas-fired plant, and approximately 63% lower compared to a coal-fired power plant.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45817535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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