The argument over fiscal decentralization and carbon dioxide emission(CO_(2))reduction has received much attention.However,evidence to back this claim is limited.Economic theory predicts that fiscal decentralization a...The argument over fiscal decentralization and carbon dioxide emission(CO_(2))reduction has received much attention.However,evidence to back this claim is limited.Economic theory predicts that fiscal decentralization affects environmental quality,but the specifics of this relationship are still up for debate.Some scholars noted that fiscal decentralization might lead to a race to the top,whereas others contended that it would result in a race to the bottom.In light of the current debates in environmental and development economics,this study aims to provide insight into how this relationship may function in South Africa from 1960 to 2020.In contrast to the existing research,the present study uses a novel dynamic autoregressive distributed lag simulation approach to assess the positive and negative changes in fiscal decentralization,scale effect,technique effect,technological innovation,foreign direct investment,energy consumption,industrial growth,and trade openness on CO_(2)emissions.The following are the main findings:(i)Fiscal decentralization had a CO_(2)emission reduction impact in the short and long run,highlighting the presence of the race to the top approach.(ii)Economic growth(as represented by the scale effect)eroded ecological integrity.However,its square(as expressed by technique effect)aided in strengthening ecological protection,validating the environmental Kuznets curve hypothesis.(iii)CO_(2)emissions were driven by energy utilization,trade openness,industrial value-added,and foreign direct investment,whereas technological innovation boosted ecological integrity.Findings suggest that further fiscal decentralization should be undertaken through further devolution of power to local entities,particularly regarding environmental policy issues,to maintain South Africa’s ecological sustainability.South Africa should also establish policies to improve environmental sustainability by strengthening a lower layer of government and clarifying responsibilities at the national and local levels to fulfill the energy-saving functions of fiscal expenditures.展开更多
Within the context of CO_(2)emission peaking and carbon neutrality,the study of CO_(2)emissions at the provincial level is few.Sichuan Province in China has not only superior clean energy resources endowment but also ...Within the context of CO_(2)emission peaking and carbon neutrality,the study of CO_(2)emissions at the provincial level is few.Sichuan Province in China has not only superior clean energy resources endowment but also great potential for the reduction of CO_(2)emissions.Therefore,using logarithmic mean Divisia index(LMDI)model to analysis the influence degree of different influencing factors on CO_(2)emissions from final energy consumption in Sichuan Province,so as to formulate corresponding emission reduction countermeasures from different paths according to the influencing factors.Based on the data of final energy consumption in Sichuan Province from 2010 to 2019,we calculated CO_(2)emission by the indirect emission calculation method.The influencing factors of CO_(2)emissions originating from final energy consumption in Sichuan Province were decomposed into population size,economic development,industrial structure,energy consumption intensity,and energy consumption structure by the Kaya-logarithmic mean Divisia index(LMDI)decomposition model.At the same time,grey correlation analysis was used to identify the correlation between CO_(2)emissions originating from final energy consumption and the influencing factors in Sichuan Province.The results showed that population size,economic development and energy consumption structure have positive contributions to CO_(2)emissions from final energy consumption in Sichuan Province,and economic development has a significant contribution to CO_(2)emissions from final energy consumption,with a contribution rate of 519.11%.The industrial structure and energy consumption intensity have negative contributions to CO_(2)emissions in Sichuan Province,and both of them have significant contributions,among which the contribution rate of energy consumption structure was 325.96%.From the perspective of industrial structure,secondary industry makes significant contributions and will maintain a restraining effect;from the perspective of energy consumption structure,industry sector has a significant contribution.The results of this paper are conducive to the implementation of carbon emission reduction policies in Sichuan Province.展开更多
The debate about climate change is highly politicized.Not everyone is convinced that CO_(2)emissions are worth curbing despite seemingly irrefutable evidence in the IPCC’s latest report.[1]Some have vested interests ...The debate about climate change is highly politicized.Not everyone is convinced that CO_(2)emissions are worth curbing despite seemingly irrefutable evidence in the IPCC’s latest report.[1]Some have vested interests in exploiting fossil fuels while others think alternative,cheaper solutions can be found.Countries that have shifted from manufacturing to service-based economies will find it easier to decarbonize.Other countries with relatively low carbon emissions per capita but large populations believe it is unfair that they should have to bear heavy costs of decarbonization to solve a problem that wealthier countries have created.展开更多
Stabilizing global climate change to within 1.5℃requires a reduction in greenhouse gas emissions,with a primary focus on carbon dioxide(CO_(2))emissions.CO_(2)flooding in oilfields has recently been recognized as an ...Stabilizing global climate change to within 1.5℃requires a reduction in greenhouse gas emissions,with a primary focus on carbon dioxide(CO_(2))emissions.CO_(2)flooding in oilfields has recently been recognized as an important way to reduce CO_(2)emissions by storing CO_(2)in oil reservoirs.This work proposes an advanced CO_(2)enhanced oil recovery(EOR)method-namely,storage-driven CO_(2)EOR-whose main target is to realize net-zero or even negative CO_(2)emissions by sequestrating the maximum possible amount of CO_(2)in oil reservoirs while accomplishing the maximum possible oil recovery.Here,dimethyl ether(DME)is employed as an efficient agent in assisting conventional CO_(2)EOR for oil recovery while enhancing CO_(2)sequestration in reservoirs.The results show that DME improves the solubility of CO_(2)in in situ oil,which is beneficial for the solubility trapping of CO_(2)storage;furthermore,the presence of DME inhibits the"escape"of lighter hydrocarbons from crude oil due to the CO_(2)extraction effect,which is critical for sustainable oil recovery.Sto rage-driven CO_(2)EOR is superior to conventional CO_(2)EOR in improving sweeping efficiency,especially during the late oil production period.This work demonstrates that storage-driven CO_(2)EOR exhibits higher oil-in-place(OIP)recovery than conventional CO_(2)EOR.Moreover,the amount of sequestrated CO_(2)in storage-driven CO_(2)EOR exceeds the amount of emissions from burning the produced oil;that is,the sequestrated CO_(2)offsets not only current emissions but also past CO_(2)emissions.By altering developing scenarios,such as water alternating storage-driven CO_(2)EOR,more CO_(2)sequestration and higher oil recovery can be achieved.This work demonstrates the potential utilization of DME as an efficient additive to CO_(2)for enhancing oil recovery while improving CO_(2)storage in oil reservoirs.展开更多
Estimating the impacts on PM_(2.5)pollution and CO_(2)emissions by human activities in different urban regions is important for developing efficient policies.In early 2020,China implemented a lockdown policy to contai...Estimating the impacts on PM_(2.5)pollution and CO_(2)emissions by human activities in different urban regions is important for developing efficient policies.In early 2020,China implemented a lockdown policy to contain the spread of COVID-19,resulting in a significant reduction of human activities.This event presents a convenient opportunity to study the impact of human activities in the transportation and industrial sectors on air pollution.Here,we investigate the variations in air quality attributed to the COVID-19 lockdown policy in the megacities of China by combining in-situ environmental and meteorological datasets,the Suomi-NPP/VIIRS and the CO_(2)emissions from the Carbon Monitor project.Our study shows that PM_(2.5)concentrations in the spring of 2020 decreased by 41.87%in the Yangtze River Delta(YRD)and 43.30%in the Pearl River Delta(PRD),respectively,owing to the significant shutdown of traffic and manufacturing industries.However,PM_(2.5)concentrations in the Beijing-Tianjin-Hebei(BTH)region only decreased by 2.01%because the energy and steel industries were not fully paused.In addition,unfavorable weather conditions contributed to further increases in the PM_(2.5)concentration.Furthermore,CO_(2)concentrations were not significantly affected in China during the short-term emission reduction,despite a 19.52%reduction in CO_(2)emissions compared to the same period in 2019.Our results suggest that concerted efforts from different emission sectors and effective long-term emission reduction strategies are necessary to control air pollution and CO_(2)emissions.展开更多
Detailed research on China's CO_(2) emission pathway of the 2030 peak and 2060 carbon neutrality goals is fundamental to promote China's climate change action.Previous studies on emission pathways have been ba...Detailed research on China's CO_(2) emission pathway of the 2030 peak and 2060 carbon neutrality goals is fundamental to promote China's climate change action.Previous studies on emission pathways have been based on long-term emission data or model analyses.However,few studies have achieved synergy and pathway optimization at both the micro and macro levels or focused on China's 2060 carbon neutrality goal,making it difficult to support the systematic management of national and regional emission pathways.In this study,we developed an integrated CO_(2) emission pathway model,the Chinese Academy of Environmental Planning Carbon Pathways 1.2 model,under China's climate change goals.Our pathway coupled the top-down and bottom-up approaches and conducted optimization analysis under social fairness and optimal cost conditions.The results provide a clear CO_(2) emission pathway and offer insights for implementing fine management of CO_(2) emissions at the national,regional,sectoral,and spatial gridded levels.展开更多
Green development has become an increasingly important global initiative.Therefore,this study focuses on the impact of green product exports on carbon emissions in China.Firm-level datasets are used to estimate provin...Green development has become an increasingly important global initiative.Therefore,this study focuses on the impact of green product exports on carbon emissions in China.Firm-level datasets are used to estimate provincial green product exports between 2001-2016.This study estimates the impact of green exports on carbon emissions using the system generalized method of moments methodology.In addition,heterogeneity and asymmetry of the nexus are explored.The following findings are highlighted:(1)China’s green product exports show a significant upward trend during the study period;(2)increased green product exports,especially those of high-technology manufacturers,can effectively mitigate CO_(2) emissions;(3)the influence of green product exports on carbon emissions is regional heterogeneous but consistent across quantiles;and(4)technique and scale effects are significant mediators,whereas the composition effect is not.These findings provide new evidence supporting methods to mitigate China’s CO_(2) emissions by adjusting green product export structures.展开更多
This research utilizes geospatial methodologies to investigate the influence of gas flaring and carbon dioxide emissions on precipitation patterns within the Niger Delta region of Nigeria.The study relies on average m...This research utilizes geospatial methodologies to investigate the influence of gas flaring and carbon dioxide emissions on precipitation patterns within the Niger Delta region of Nigeria.The study relies on average mean precipitation data sourced from CHRS at the University of Arizona and carbon dioxide emissions data from NASA’s AIRS in Giovanni,spanning from July 2002 to November 2011.To carry out the analysis,ArcGIS 5.0 and SPSS 25,employing Inverse Distance Weighting(IDW),were employed to assess CO_(2) emissions and rainfall for both November and July during the period from 2002 to 2011.Over the course of this study,it was observed that CO_(2) emission exhibited an upward trend,increasing from 327.5226 parts per million(ppm)in July 2002 to 390.0077 ppm in November 2011.Simultaneously,the rainfall demonstrated an increase,rising from 56.66 millimeters to 390.78 millimeters for both July and November from 2002 to 2011.Noteworthy findings emerged from the correlation analysis conducted.Specifically,from July 2000 to 2011,there was a weak positive correlation(0.3858)observed between CO_(2) emissions and minimum rainfall,while a strong negative correlation(–0.7998)was identified for maximum rainfall values.In November,both minimum and maximum CO_(2) emissions displayed strong negative correlations with rainfall,with coefficients of–0.8255 and–0.7415,respectively.These findings hold significant implications for comprehending the environmental dynamics within the Niger Delta.Policymakers and stakeholders can leverage this knowledge to formulate targeted strategies aimed at mitigating CO_(2) emissions and addressing potential climate change-induced alterations in rainfall patterns.展开更多
CO_(2)emission inventory provides fundamental data for climate research and emission mitigation.Currently,most global CO_(2)emission inventories were developed with energy statistics from International Energy Agency(I...CO_(2)emission inventory provides fundamental data for climate research and emission mitigation.Currently,most global CO_(2)emission inventories were developed with energy statistics from International Energy Agency(IEA)and were available at country level with limited source categories.Here,as the first step toward a high-resolution and dynamic updated global CO_(2)emission database,we developed a data-driven approach to construct seamless and highly-resolved energy consumption data cubes for 208 countries/territories,797 sub-country administrative divisions in 29 countries,42 fuel types,and 52 sectors,with the fusion of activity data from 24 international statistics and 65 regional/local statistics.Global CO_(2)emissions from fossil fuel combustion and cement production in 1970–2021 were then estimated with highly-resolved source category(1,484 of total)and sub-country information(797 of total).Specifically,73%of global CO_(2)emissions in 2021 were estimated with sub-country information,providing considerably improved spatial resolution for global CO_(2)emission accounting.With the support of detailed information,the dynamics of global CO_(2)emissions across sectors and fuel types were presented,representing the evolution of global economy and progress of climate mitigation.Remarkable differences of sectoral contribution were found across sub-country administrative divisions within a given country,revealing the uneven distribution of energy and economic structure among different regions.Our estimates were generally consistent with existing databases at aggregated level for global total or large emitters,while large discrepancies were observed for middle and small emitters.Our database,named the Multiresolution Emission Inventory model for Climate and air pollution research(MEIC)is publicly available through http://meicmodel.org.cn with highly-resolved information and timely update,which provides an independent carbon emission accounting data source for climate research.展开更多
In 2021,China updated its nationally determined contributions(NDCs)under the Paris Agreement,which prompts a more accurate mea-surement of its emissions inventory and a reasonable pathway toward carbon neutrality by 2...In 2021,China updated its nationally determined contributions(NDCs)under the Paris Agreement,which prompts a more accurate mea-surement of its emissions inventory and a reasonable pathway toward carbon neutrality by 2060.This study reviews the estimates using the bottom-up emissions factor method or the top-down atmospheric CO_(2) concentration inversion method to derive China's CO_(2) emissions inventory and finds that CO_(2) emissions from energy combustion and industrial processes in Chinese mainland range from 11.3-12.0 GtCO_(2) in 2021.Based on a comprehensive review of pathways proposed by domestic and international studies and an analysis of the origins of their differences,we proposed the Tsinghua-CMA pathway that coordinates the 2℃global temperature rise control target with China's current CO_(2) emissions status and mitigation policies.The pathway requires China's CO_(2) emissions to peak around 2028-2029 at about 12.8 GtCO_(2),then decline steadily to about 11.2 GtCO_(2) in 2035,3.6 GtCO_(2) in 2050,and 0.9 GtCO_(2) in 2060.Compared to a reference scenario without updated NDCs,this pathway would result in an economic cost of about 0.9%cumulative GDP between 2020 and 2060,only 1/4-1/3 of the cost associated with pathways that align with the 1.5℃target.We recommended that China improves emissions accounting by cross-validating bottom-up and top-down approaches and regularly updating the pathway toward carbon neutrality while maintaining consistency with its evolving CO_(2) emissions inventory,policy trends,and global CO_(2) emission budget updates.展开更多
An increasing divergence regarding fuel consumption(and/or CO_(2)emissions) between realworld and type-approval values for light-duty gasoline vehicles(LDGVs) has posed severe challenges to mitigating greenhouse gases...An increasing divergence regarding fuel consumption(and/or CO_(2)emissions) between realworld and type-approval values for light-duty gasoline vehicles(LDGVs) has posed severe challenges to mitigating greenhouse gases(GHGs) and achieving carbon emissions peak and neutrality. To address this divergence issue, laboratory test cycles with more real-featured and transient traffic patterns have been developed recently, for example, the China Lightduty Vehicle Test Cycle for Passenger cars(CLTC-P). We collected fuel consumption and CO_(2)emissions data of a LDGV under various conditions based on laboratory chassis dynamometer and on-road tests. Laboratory results showed that both standard test cycles and setting methods of road load affected fuel consumption slightly, with variations of less than 4%. Compared to the type-approval value, laboratory and on-road fuel consumption of the tested LDGV over the CLTC-P increased by 9% and 34% under the reference condition(i.e., air conditioning off, automatic stop and start(STT) on and two passengers). On-road measurement results indicated that fuel consumption under the low-speed phase of the CLTC-P increased by 12% due to the STT off, although only a 4% increase on average over the entire cycle. More fuel consumption increases(52%) were attributed to air conditioning usage and full passenger capacity. Strong correlations(R2> 0.9) between relative fuel consumption and average speed were also identified. Under traffic congestion(average speed below 25 km/hr), fuel consumption was highly sensitive to changes in vehicle speed. Thus,we suggest that real-world driving conditions cannot be ignored when evaluating the fuel economy and GHGs reduction of LDGVs.展开更多
As the proportion of electricity in final energy consumption gradually increases,CO_(2) emissions reduction actions in the power system will become the key to achieving China’s carbon-peak and carbon-neutrality goals...As the proportion of electricity in final energy consumption gradually increases,CO_(2) emissions reduction actions in the power system will become the key to achieving China’s carbon-peak and carbon-neutrality goals.It is essential to analyse and quantify the driving forces of CO_(2) emissions from electricity generation in the fossil-rich area in China.This paper aims to identify the characteristics of CO_(2) emissions generated by electricity and provide a basis for formulating CO_(2)-reduction policies in power systems.First,we analyse the current state of CO_(2) emissions from electricity generation in Anhui Province that was dominated by fossil energy during the period 2010-19.Then,we apply the logarithmic mean Divisia index method to find the nature of the factors influencing the changes in CO_(2) emissions.Finally,we analyse the CO_(2)-reduction measures of each side of the source-network-load-storage of the power system in Anhui through a power-system carbon-reduction path analysis model proposed in this study and provide policy suggestions.The results showed the following.(i)CO_(2) emissions in Anhui Province continued to increase from 2010 to 2019 and the trend in the growth rate of CO_(2) emissions presented approximately a u-shaped curve.(ii)Economic activity has always been the dominant factor driving the growth of electricity CO_(2) emis-sions.The increase in the proportion of renewable energy in power generation,the improvement in thermal power-conversion efficiency and the decrease in the intensity of power consumption are the three major driving factors for the reduction in CO_(2) emissions from power generation in Anhui.(iii)The CO_(2)-reduction measures of the power system are provided in each link of the source-network-load-storage,such as developing the photovoltaic industry and building energy storage,upgrading and transforming coal-fired power stations,redu-cing the loss rate of transmission lines on the grid side and improving the efficiency of the utilization of electricity on the user side.展开更多
With the development of the bike-sharing system(BSS)and the introduction of green and low carbon development,the environmental impacts of BSS had received increasing attention in recent years.However,the emissions fro...With the development of the bike-sharing system(BSS)and the introduction of green and low carbon development,the environmental impacts of BSS had received increasing attention in recent years.However,the emissions from the rebalancing of BSS,where fossil-fueled vehicles are commonly used,are usually neglected,which goes against the idea of green travel in a sharing economy.Previous studies on the bike-sharing rebalancing problem(BRP),which is considered NP-hard,have mainly focused on algorithm innovation instead of improving the solution model,thereby hindering the application of many existing models in large-scale BRP.This study then proposes a method for optimizing the CO_(2)emissions from BRP and takes the BSS of Beijing as a demonstration.We initially analyze the spatial and temporal characteristics of BSS,especially the flow between districts,and find that each district can be independently rebalanced.Afterward,we develop a rebalancing optimization model based on a partitioning strategy to avoid deciding the number of bikes being loaded or unloaded at each parking node.We then employ the tabu search algorithm to solve the model.Results show that(i)due to over launch and lack of planning in rebalancing,the BSS in Beijing shows great potential for optimization,such as by reducing the number of vehicle routes,CO_(2)emissions,and unmet demands;(ii)the CO_(2)emissions of BSS in Beijing can be reduced by 57.5%by forming balanced parking nodes at the end of the day and decreasing the repetition of vehicle routes and the loads of vehicles;and(iii)the launch amounts of bikes in specific districts,such as Shijingshan and Mentougou,should be increased.展开更多
As an important transportation infrastructure and transportation backbone in China,high-speed rail(HSR)plays a critical role in promoting the development of green and low-carbon transportation.Calculating the CO_(2) e...As an important transportation infrastructure and transportation backbone in China,high-speed rail(HSR)plays a critical role in promoting the development of green and low-carbon transportation.Calculating the CO_(2) emissions reduction performance of HSR will be conduci v e to pr omote the CO_(2) emissions r eduction w ork of the r ail w ay.Based on the Dalkic HSR CO_(2) emissions r eduction performance model,by adjusting the HSR CO_(2) emission factor(CEF HSR),the annual times of departures(T)and other parameters,this study develops a Chinese HSR CO_(2) emissions reduction performance model.Taking the Beijing-Shanghai HSR as the resear c h object,this study conducts a questionnaire survey to explore the substitution effect and demand effect of HSR on different transportation modes;collects data such as passenger v olume,av era ge electricity use and annual times of departures of the Beijing-Shanghai HSR in 2019;and calculates the CO_(2) emissions reduction performance of the Beijing-Shanghai HSR.This study has two main results:(1)It builds a Chinese HSR CO_(2) emissions reduction performance model based on substitution effect and demand effect.(2)In 2019,the CO_(2) emissions of the Beijing-Shanghai HSR are 2898233.62 t,the CO_(2) emissions reduction performance of the Beijing-Shanghai HSR is 17999482.8 t,the annual CO_(2) emissions of the Beijing-Shanghai line in‘No HSR’case are 7.2 times as in the’HSR’case and the PKT of the HSR is 10.2 g/pkm.Based on the research results,this study proposes three CO_(2) emissions reduction policy suggestions.This study would be helpful for further HSR CO_(2) emissions reduction resear c h and departments related to railway transportation management to make CO_(2) emissions reduction policies.展开更多
Developing countries are facing the problem of environmental degradation.Environmental degradation is caused by the use of non-renewable energy consumptions for economic growth but the consequences of environmental de...Developing countries are facing the problem of environmental degradation.Environmental degradation is caused by the use of non-renewable energy consumptions for economic growth but the consequences of environmental degradation cannot be ignored.This primary purpose of this study is to investigate the nexus between energy consumption,economic growth and CO_(2) emission in Pakistan by using annual time series data from 1965 to 2015.The estimated results of ARDL indicate that energy consumption and economic growth increase the CO_(2) emissions in Pakistan both in short run and long run.Based on the estimated results it is recommended that policy maker in Pakistan should adopt and promote such renewable energy sources that will help to meet the increased demand for energy by replacing old traditional energy sources such as coal,gas,and oil.Renewable energy sources are reusable that can reduce the CO_(2) emissions and also ensure sustainable economic development of Pakistan.展开更多
The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct an...The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct and indirect consequences on ecologi-cal quality utilizing the environmental Kuznets curve(EKC)methodological approach.Our empirical analysis is based on the novel dynamic autoregressive distributed lag simulations approach for South Africa between 1960 and 2020.The results,which used five distinct financial development measures,demonstrate that financial develop-ment boosts ecological integrity and environmental sustainability over the long and short terms.In the instance of South Africa,we additionally confirm the validity of the EKC theory.More importantly,the outcomes of the indirect channels demonstrate that financial development increases energy usage’s role in causing pollution while attenuating the detrimental impacts of economic growth,trade openness,and foreign direct investment on ecological quality.Moreover,the presence of an inadequate financial system is a requirement for the basis of the pollution haven hypothesis(PHH),which we examine using trade openness and foreign direct investment variables.PHH for both of these variables disappears when financial development crosses specified thresholds.Finally,industrial value addition destroys ecological quality while tech-nological innovation enhances it.This research provides some crucial policy recom-mendations and fresh perspectives for South Africa as it develops national initiatives to support ecological sustainability and reach its net zero emissions goal.展开更多
In order to develop limonite and decrease CO_(2) emissions,siderite is proposed as a clean reductant for suspension magnetization roasting(SMR) of limonite.An iron concentrate(iron grade:65.92wt%,iron recovery:98.54wt...In order to develop limonite and decrease CO_(2) emissions,siderite is proposed as a clean reductant for suspension magnetization roasting(SMR) of limonite.An iron concentrate(iron grade:65.92wt%,iron recovery:98.54wt%) was obtained by magnetic separation under the optimum SMR conditions:siderite dosage 40wt%,roasting temperature 700℃,roasting time 10 min.According to the magnetic analysis,SMR achieved the conversion of weak magnetic minerals to strong magnetic minerals,thus enabling the recovery of iron via magnetic separation.Based on the phase transformation analysis,during the SMR process,limonite was first dehydrated and converted to hematite,and then siderite decomposed to generate magnetite and CO,where CO reduced the freshly formed hematite to magnetite.The microstructure evolution analysis indicated that the magnetite particles were loose and porous with a destroyed structure,making them easier to be ground.The non-isothermal kinetic results show that the main reaction between limonite and siderite conformed to the two-dimension diffusion mechanism,suggesting that the diffusion of CO controlled the reaction.These results encourage the application of siderite as a reductant in SMR.展开更多
Carbon dioxide(CO_(2))is the main contributor to greenhouse gases that affect global warming.The industrial sector is the third largest producer of CO_(2) and the cement industry is one of the industries that consiste...Carbon dioxide(CO_(2))is the main contributor to greenhouse gases that affect global warming.The industrial sector is the third largest producer of CO_(2) and the cement industry is one of the industries that consistently produces the most significant CO_(2) emissions.The cement industry produces 5-8% of global CO_(2) emissions.Several methods for reducing specific CO_(2) emissions have been reported in the cement industry,including calcium looping,which uses the reversible reaction between calcination[calcium carbonate(CaCO_(3))decomposition]and carbonation[CO_(2) capture by calcium oxide(CaO)].This work investigates calcium looping employing limestone obtained directly from several cement factories in Indonesia to observe the carbon-absorption characteristics of limestone from different mining locations.The experiment was carried out using a tube furnace equipped with a controlled atmospheric condition that functions as a calciner and a carbonator.X-ray diffraction and scanning electron microscopy with energy-dispersive x-ray spec-troscopy characterization were conducted to analyse the changes in the experimental samples.The results demonstrated that the reactor configuration was capable of performing the calcination process,which converted CaCO_(3) to calcium hydroxide[Ca(OH)_(2)],as well as the carbonation process,which captured carbon and converted it back to CaCO_(3).Parametric analysis was performed on both reactions,including pressure,temperature,duration,particle size and reaction atmosphere.The results show that the limestone obtained from all sites can be used as the sorbents for the calcium-looping process with an average reactivity of 59.01%.Limestone from cement plants in various parts of Indonesia has the potential to be used as carbon sorbents in calcium-looping technology.With a similar CO_(2) concentration as the flue gas of 16.67%,the experimental results show that Bayah limestone has the maximum reactivity,as shown by the highest carbon-content addition of 12.15 wt% and has the highest CO_(2)-capture capability up to>75% per mole of Ca(OH)_(2) as a sorbent.Similar levels of the ability to capture CO_(2) per mole of Ca(OH)_(2) can be found in other limestones,ranging from 14.85% to 34.07%.The results show a promising performance of raw limestones from different mining sites,allowing further study and observation of the possibility of CO_(2) emission reduction in the sustainable cement-production process.展开更多
A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is studied.The considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming Pote...A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is studied.The considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming Potential.The main objective is the optimization of energy efficiency in order to minimize the environmental impact through the implementation of a sustainable strategy.It is shown that Exergy Analysis itself is a valuable tool in energy integration.Within the imposed framework of minimizing total annual costs,entropy analysis can be instrumental in determining the optimal plant concept,optimizing energy conversion and use,and improving profitability.The present results are discussed under the optimistic hope that they may help to define new energy and environmental policies.展开更多
文摘The argument over fiscal decentralization and carbon dioxide emission(CO_(2))reduction has received much attention.However,evidence to back this claim is limited.Economic theory predicts that fiscal decentralization affects environmental quality,but the specifics of this relationship are still up for debate.Some scholars noted that fiscal decentralization might lead to a race to the top,whereas others contended that it would result in a race to the bottom.In light of the current debates in environmental and development economics,this study aims to provide insight into how this relationship may function in South Africa from 1960 to 2020.In contrast to the existing research,the present study uses a novel dynamic autoregressive distributed lag simulation approach to assess the positive and negative changes in fiscal decentralization,scale effect,technique effect,technological innovation,foreign direct investment,energy consumption,industrial growth,and trade openness on CO_(2)emissions.The following are the main findings:(i)Fiscal decentralization had a CO_(2)emission reduction impact in the short and long run,highlighting the presence of the race to the top approach.(ii)Economic growth(as represented by the scale effect)eroded ecological integrity.However,its square(as expressed by technique effect)aided in strengthening ecological protection,validating the environmental Kuznets curve hypothesis.(iii)CO_(2)emissions were driven by energy utilization,trade openness,industrial value-added,and foreign direct investment,whereas technological innovation boosted ecological integrity.Findings suggest that further fiscal decentralization should be undertaken through further devolution of power to local entities,particularly regarding environmental policy issues,to maintain South Africa’s ecological sustainability.South Africa should also establish policies to improve environmental sustainability by strengthening a lower layer of government and clarifying responsibilities at the national and local levels to fulfill the energy-saving functions of fiscal expenditures.
基金supported by the Consultative and Research Project of the Chinese Academy of Engineering(2020-XY-19 and 2019-ZD-34)the Guangdong Basic and Applied Basic Research Foundation(2020A1515011230)the Humanities and Social Science Foundation of the Ministry of Education of China(16YJCZH162).
基金financially supported by the National Natural Science Foundation of China(41771535)the National Social Science Foundation Major Project(20&ZD092)。
文摘Within the context of CO_(2)emission peaking and carbon neutrality,the study of CO_(2)emissions at the provincial level is few.Sichuan Province in China has not only superior clean energy resources endowment but also great potential for the reduction of CO_(2)emissions.Therefore,using logarithmic mean Divisia index(LMDI)model to analysis the influence degree of different influencing factors on CO_(2)emissions from final energy consumption in Sichuan Province,so as to formulate corresponding emission reduction countermeasures from different paths according to the influencing factors.Based on the data of final energy consumption in Sichuan Province from 2010 to 2019,we calculated CO_(2)emission by the indirect emission calculation method.The influencing factors of CO_(2)emissions originating from final energy consumption in Sichuan Province were decomposed into population size,economic development,industrial structure,energy consumption intensity,and energy consumption structure by the Kaya-logarithmic mean Divisia index(LMDI)decomposition model.At the same time,grey correlation analysis was used to identify the correlation between CO_(2)emissions originating from final energy consumption and the influencing factors in Sichuan Province.The results showed that population size,economic development and energy consumption structure have positive contributions to CO_(2)emissions from final energy consumption in Sichuan Province,and economic development has a significant contribution to CO_(2)emissions from final energy consumption,with a contribution rate of 519.11%.The industrial structure and energy consumption intensity have negative contributions to CO_(2)emissions in Sichuan Province,and both of them have significant contributions,among which the contribution rate of energy consumption structure was 325.96%.From the perspective of industrial structure,secondary industry makes significant contributions and will maintain a restraining effect;from the perspective of energy consumption structure,industry sector has a significant contribution.The results of this paper are conducive to the implementation of carbon emission reduction policies in Sichuan Province.
文摘The debate about climate change is highly politicized.Not everyone is convinced that CO_(2)emissions are worth curbing despite seemingly irrefutable evidence in the IPCC’s latest report.[1]Some have vested interests in exploiting fossil fuels while others think alternative,cheaper solutions can be found.Countries that have shifted from manufacturing to service-based economies will find it easier to decarbonize.Other countries with relatively low carbon emissions per capita but large populations believe it is unfair that they should have to bear heavy costs of decarbonization to solve a problem that wealthier countries have created.
基金financial support from the Science Foundation of China University of Petroleum,Beijing(2462021QNXZ012 and 2462021YJRC012)supported by the Fundamental Research Funds for the Central Universities。
文摘Stabilizing global climate change to within 1.5℃requires a reduction in greenhouse gas emissions,with a primary focus on carbon dioxide(CO_(2))emissions.CO_(2)flooding in oilfields has recently been recognized as an important way to reduce CO_(2)emissions by storing CO_(2)in oil reservoirs.This work proposes an advanced CO_(2)enhanced oil recovery(EOR)method-namely,storage-driven CO_(2)EOR-whose main target is to realize net-zero or even negative CO_(2)emissions by sequestrating the maximum possible amount of CO_(2)in oil reservoirs while accomplishing the maximum possible oil recovery.Here,dimethyl ether(DME)is employed as an efficient agent in assisting conventional CO_(2)EOR for oil recovery while enhancing CO_(2)sequestration in reservoirs.The results show that DME improves the solubility of CO_(2)in in situ oil,which is beneficial for the solubility trapping of CO_(2)storage;furthermore,the presence of DME inhibits the"escape"of lighter hydrocarbons from crude oil due to the CO_(2)extraction effect,which is critical for sustainable oil recovery.Sto rage-driven CO_(2)EOR is superior to conventional CO_(2)EOR in improving sweeping efficiency,especially during the late oil production period.This work demonstrates that storage-driven CO_(2)EOR exhibits higher oil-in-place(OIP)recovery than conventional CO_(2)EOR.Moreover,the amount of sequestrated CO_(2)in storage-driven CO_(2)EOR exceeds the amount of emissions from burning the produced oil;that is,the sequestrated CO_(2)offsets not only current emissions but also past CO_(2)emissions.By altering developing scenarios,such as water alternating storage-driven CO_(2)EOR,more CO_(2)sequestration and higher oil recovery can be achieved.This work demonstrates the potential utilization of DME as an efficient additive to CO_(2)for enhancing oil recovery while improving CO_(2)storage in oil reservoirs.
基金supported by the National Science Foundation of China(Grant.No.41521004)the Gansu Provincial Special Fund Project for Guiding Scientific and Technological Innovation and Development(Grant No.2019ZX-06)the Fundamental Research Funds for the Central Universit-ies(lzujbky-2021-kb12)。
文摘Estimating the impacts on PM_(2.5)pollution and CO_(2)emissions by human activities in different urban regions is important for developing efficient policies.In early 2020,China implemented a lockdown policy to contain the spread of COVID-19,resulting in a significant reduction of human activities.This event presents a convenient opportunity to study the impact of human activities in the transportation and industrial sectors on air pollution.Here,we investigate the variations in air quality attributed to the COVID-19 lockdown policy in the megacities of China by combining in-situ environmental and meteorological datasets,the Suomi-NPP/VIIRS and the CO_(2)emissions from the Carbon Monitor project.Our study shows that PM_(2.5)concentrations in the spring of 2020 decreased by 41.87%in the Yangtze River Delta(YRD)and 43.30%in the Pearl River Delta(PRD),respectively,owing to the significant shutdown of traffic and manufacturing industries.However,PM_(2.5)concentrations in the Beijing-Tianjin-Hebei(BTH)region only decreased by 2.01%because the energy and steel industries were not fully paused.In addition,unfavorable weather conditions contributed to further increases in the PM_(2.5)concentration.Furthermore,CO_(2)concentrations were not significantly affected in China during the short-term emission reduction,despite a 19.52%reduction in CO_(2)emissions compared to the same period in 2019.Our results suggest that concerted efforts from different emission sectors and effective long-term emission reduction strategies are necessary to control air pollution and CO_(2)emissions.
基金The research was funded by the project“An Emission Scenario Air Quality Model Based Study on the Evaluation of‘Dual Attainments’of Chinese City”[Grant number.72074154],supported by the National Natural Science Foundation of China.
文摘Detailed research on China's CO_(2) emission pathway of the 2030 peak and 2060 carbon neutrality goals is fundamental to promote China's climate change action.Previous studies on emission pathways have been based on long-term emission data or model analyses.However,few studies have achieved synergy and pathway optimization at both the micro and macro levels or focused on China's 2060 carbon neutrality goal,making it difficult to support the systematic management of national and regional emission pathways.In this study,we developed an integrated CO_(2) emission pathway model,the Chinese Academy of Environmental Planning Carbon Pathways 1.2 model,under China's climate change goals.Our pathway coupled the top-down and bottom-up approaches and conducted optimization analysis under social fairness and optimal cost conditions.The results provide a clear CO_(2) emission pathway and offer insights for implementing fine management of CO_(2) emissions at the national,regional,sectoral,and spatial gridded levels.
基金This study was supported by the National Social Science Foundation of China[Grant number.20VGQ003].
文摘Green development has become an increasingly important global initiative.Therefore,this study focuses on the impact of green product exports on carbon emissions in China.Firm-level datasets are used to estimate provincial green product exports between 2001-2016.This study estimates the impact of green exports on carbon emissions using the system generalized method of moments methodology.In addition,heterogeneity and asymmetry of the nexus are explored.The following findings are highlighted:(1)China’s green product exports show a significant upward trend during the study period;(2)increased green product exports,especially those of high-technology manufacturers,can effectively mitigate CO_(2) emissions;(3)the influence of green product exports on carbon emissions is regional heterogeneous but consistent across quantiles;and(4)technique and scale effects are significant mediators,whereas the composition effect is not.These findings provide new evidence supporting methods to mitigate China’s CO_(2) emissions by adjusting green product export structures.
文摘This research utilizes geospatial methodologies to investigate the influence of gas flaring and carbon dioxide emissions on precipitation patterns within the Niger Delta region of Nigeria.The study relies on average mean precipitation data sourced from CHRS at the University of Arizona and carbon dioxide emissions data from NASA’s AIRS in Giovanni,spanning from July 2002 to November 2011.To carry out the analysis,ArcGIS 5.0 and SPSS 25,employing Inverse Distance Weighting(IDW),were employed to assess CO_(2) emissions and rainfall for both November and July during the period from 2002 to 2011.Over the course of this study,it was observed that CO_(2) emission exhibited an upward trend,increasing from 327.5226 parts per million(ppm)in July 2002 to 390.0077 ppm in November 2011.Simultaneously,the rainfall demonstrated an increase,rising from 56.66 millimeters to 390.78 millimeters for both July and November from 2002 to 2011.Noteworthy findings emerged from the correlation analysis conducted.Specifically,from July 2000 to 2011,there was a weak positive correlation(0.3858)observed between CO_(2) emissions and minimum rainfall,while a strong negative correlation(–0.7998)was identified for maximum rainfall values.In November,both minimum and maximum CO_(2) emissions displayed strong negative correlations with rainfall,with coefficients of–0.8255 and–0.7415,respectively.These findings hold significant implications for comprehending the environmental dynamics within the Niger Delta.Policymakers and stakeholders can leverage this knowledge to formulate targeted strategies aimed at mitigating CO_(2) emissions and addressing potential climate change-induced alterations in rainfall patterns.
基金supported by the National Natural Science Foundation of China(Grant No.41921005)the Major Project of High Resolution Earth Observation System(Grant No.30Y60B01-9003-22/23)+1 种基金the New Cornerstone Science Foundation through the XPLORER PRIZEthe Tsinghua University Initiative Scientific Research Program(Grant No.20223080041)。
文摘CO_(2)emission inventory provides fundamental data for climate research and emission mitigation.Currently,most global CO_(2)emission inventories were developed with energy statistics from International Energy Agency(IEA)and were available at country level with limited source categories.Here,as the first step toward a high-resolution and dynamic updated global CO_(2)emission database,we developed a data-driven approach to construct seamless and highly-resolved energy consumption data cubes for 208 countries/territories,797 sub-country administrative divisions in 29 countries,42 fuel types,and 52 sectors,with the fusion of activity data from 24 international statistics and 65 regional/local statistics.Global CO_(2)emissions from fossil fuel combustion and cement production in 1970–2021 were then estimated with highly-resolved source category(1,484 of total)and sub-country information(797 of total).Specifically,73%of global CO_(2)emissions in 2021 were estimated with sub-country information,providing considerably improved spatial resolution for global CO_(2)emission accounting.With the support of detailed information,the dynamics of global CO_(2)emissions across sectors and fuel types were presented,representing the evolution of global economy and progress of climate mitigation.Remarkable differences of sectoral contribution were found across sub-country administrative divisions within a given country,revealing the uneven distribution of energy and economic structure among different regions.Our estimates were generally consistent with existing databases at aggregated level for global total or large emitters,while large discrepancies were observed for middle and small emitters.Our database,named the Multiresolution Emission Inventory model for Climate and air pollution research(MEIC)is publicly available through http://meicmodel.org.cn with highly-resolved information and timely update,which provides an independent carbon emission accounting data source for climate research.
基金supported by the Special Project (42341202 and 72140005)of the National Natural Science Foundation of China,Pathways to Achieve Carbon Neutrality。
文摘In 2021,China updated its nationally determined contributions(NDCs)under the Paris Agreement,which prompts a more accurate mea-surement of its emissions inventory and a reasonable pathway toward carbon neutrality by 2060.This study reviews the estimates using the bottom-up emissions factor method or the top-down atmospheric CO_(2) concentration inversion method to derive China's CO_(2) emissions inventory and finds that CO_(2) emissions from energy combustion and industrial processes in Chinese mainland range from 11.3-12.0 GtCO_(2) in 2021.Based on a comprehensive review of pathways proposed by domestic and international studies and an analysis of the origins of their differences,we proposed the Tsinghua-CMA pathway that coordinates the 2℃global temperature rise control target with China's current CO_(2) emissions status and mitigation policies.The pathway requires China's CO_(2) emissions to peak around 2028-2029 at about 12.8 GtCO_(2),then decline steadily to about 11.2 GtCO_(2) in 2035,3.6 GtCO_(2) in 2050,and 0.9 GtCO_(2) in 2060.Compared to a reference scenario without updated NDCs,this pathway would result in an economic cost of about 0.9%cumulative GDP between 2020 and 2060,only 1/4-1/3 of the cost associated with pathways that align with the 1.5℃target.We recommended that China improves emissions accounting by cross-validating bottom-up and top-down approaches and regularly updating the pathway toward carbon neutrality while maintaining consistency with its evolving CO_(2) emissions inventory,policy trends,and global CO_(2) emission budget updates.
基金sponsored by the National Natural Science Foundation of China (Nos. 52170111 and 41977180)the first China First Automobile Works (FAW)-Volkswagen China Environmental Protection Foundation automobile environmental protection innovation leading plan。
文摘An increasing divergence regarding fuel consumption(and/or CO_(2)emissions) between realworld and type-approval values for light-duty gasoline vehicles(LDGVs) has posed severe challenges to mitigating greenhouse gases(GHGs) and achieving carbon emissions peak and neutrality. To address this divergence issue, laboratory test cycles with more real-featured and transient traffic patterns have been developed recently, for example, the China Lightduty Vehicle Test Cycle for Passenger cars(CLTC-P). We collected fuel consumption and CO_(2)emissions data of a LDGV under various conditions based on laboratory chassis dynamometer and on-road tests. Laboratory results showed that both standard test cycles and setting methods of road load affected fuel consumption slightly, with variations of less than 4%. Compared to the type-approval value, laboratory and on-road fuel consumption of the tested LDGV over the CLTC-P increased by 9% and 34% under the reference condition(i.e., air conditioning off, automatic stop and start(STT) on and two passengers). On-road measurement results indicated that fuel consumption under the low-speed phase of the CLTC-P increased by 12% due to the STT off, although only a 4% increase on average over the entire cycle. More fuel consumption increases(52%) were attributed to air conditioning usage and full passenger capacity. Strong correlations(R2> 0.9) between relative fuel consumption and average speed were also identified. Under traffic congestion(average speed below 25 km/hr), fuel consumption was highly sensitive to changes in vehicle speed. Thus,we suggest that real-world driving conditions cannot be ignored when evaluating the fuel economy and GHGs reduction of LDGVs.
基金support from the State Grid Economic and Technological Research Institute,and financial support from the State Grid Corporation of China Headquarters Technology Project‘Research on Electricity Carbon Emission Accounting Methods and Key Technologies in New Type of Power System’(Project Number:52182021N006).
文摘As the proportion of electricity in final energy consumption gradually increases,CO_(2) emissions reduction actions in the power system will become the key to achieving China’s carbon-peak and carbon-neutrality goals.It is essential to analyse and quantify the driving forces of CO_(2) emissions from electricity generation in the fossil-rich area in China.This paper aims to identify the characteristics of CO_(2) emissions generated by electricity and provide a basis for formulating CO_(2)-reduction policies in power systems.First,we analyse the current state of CO_(2) emissions from electricity generation in Anhui Province that was dominated by fossil energy during the period 2010-19.Then,we apply the logarithmic mean Divisia index method to find the nature of the factors influencing the changes in CO_(2) emissions.Finally,we analyse the CO_(2)-reduction measures of each side of the source-network-load-storage of the power system in Anhui through a power-system carbon-reduction path analysis model proposed in this study and provide policy suggestions.The results showed the following.(i)CO_(2) emissions in Anhui Province continued to increase from 2010 to 2019 and the trend in the growth rate of CO_(2) emissions presented approximately a u-shaped curve.(ii)Economic activity has always been the dominant factor driving the growth of electricity CO_(2) emis-sions.The increase in the proportion of renewable energy in power generation,the improvement in thermal power-conversion efficiency and the decrease in the intensity of power consumption are the three major driving factors for the reduction in CO_(2) emissions from power generation in Anhui.(iii)The CO_(2)-reduction measures of the power system are provided in each link of the source-network-load-storage,such as developing the photovoltaic industry and building energy storage,upgrading and transforming coal-fired power stations,redu-cing the loss rate of transmission lines on the grid side and improving the efficiency of the utilization of electricity on the user side.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.71871022,71828401 and 71521002)the Joint Development Program of Beijing Municipal Commission of Education,the Fok Ying Tung Education Foundation(Grant No.161076)+1 种基金the National Key R&D Program(Grant No.2016YFA0602603)the National Program for Support of Top-notch Young Professionals.
文摘With the development of the bike-sharing system(BSS)and the introduction of green and low carbon development,the environmental impacts of BSS had received increasing attention in recent years.However,the emissions from the rebalancing of BSS,where fossil-fueled vehicles are commonly used,are usually neglected,which goes against the idea of green travel in a sharing economy.Previous studies on the bike-sharing rebalancing problem(BRP),which is considered NP-hard,have mainly focused on algorithm innovation instead of improving the solution model,thereby hindering the application of many existing models in large-scale BRP.This study then proposes a method for optimizing the CO_(2)emissions from BRP and takes the BSS of Beijing as a demonstration.We initially analyze the spatial and temporal characteristics of BSS,especially the flow between districts,and find that each district can be independently rebalanced.Afterward,we develop a rebalancing optimization model based on a partitioning strategy to avoid deciding the number of bikes being loaded or unloaded at each parking node.We then employ the tabu search algorithm to solve the model.Results show that(i)due to over launch and lack of planning in rebalancing,the BSS in Beijing shows great potential for optimization,such as by reducing the number of vehicle routes,CO_(2)emissions,and unmet demands;(ii)the CO_(2)emissions of BSS in Beijing can be reduced by 57.5%by forming balanced parking nodes at the end of the day and decreasing the repetition of vehicle routes and the loads of vehicles;and(iii)the launch amounts of bikes in specific districts,such as Shijingshan and Mentougou,should be increased.
基金This study was supported by the Fundamental Research Funds for the Central Universities(Grant No.2022YJS053).
文摘As an important transportation infrastructure and transportation backbone in China,high-speed rail(HSR)plays a critical role in promoting the development of green and low-carbon transportation.Calculating the CO_(2) emissions reduction performance of HSR will be conduci v e to pr omote the CO_(2) emissions r eduction w ork of the r ail w ay.Based on the Dalkic HSR CO_(2) emissions r eduction performance model,by adjusting the HSR CO_(2) emission factor(CEF HSR),the annual times of departures(T)and other parameters,this study develops a Chinese HSR CO_(2) emissions reduction performance model.Taking the Beijing-Shanghai HSR as the resear c h object,this study conducts a questionnaire survey to explore the substitution effect and demand effect of HSR on different transportation modes;collects data such as passenger v olume,av era ge electricity use and annual times of departures of the Beijing-Shanghai HSR in 2019;and calculates the CO_(2) emissions reduction performance of the Beijing-Shanghai HSR.This study has two main results:(1)It builds a Chinese HSR CO_(2) emissions reduction performance model based on substitution effect and demand effect.(2)In 2019,the CO_(2) emissions of the Beijing-Shanghai HSR are 2898233.62 t,the CO_(2) emissions reduction performance of the Beijing-Shanghai HSR is 17999482.8 t,the annual CO_(2) emissions of the Beijing-Shanghai line in‘No HSR’case are 7.2 times as in the’HSR’case and the PKT of the HSR is 10.2 g/pkm.Based on the research results,this study proposes three CO_(2) emissions reduction policy suggestions.This study would be helpful for further HSR CO_(2) emissions reduction resear c h and departments related to railway transportation management to make CO_(2) emissions reduction policies.
文摘Developing countries are facing the problem of environmental degradation.Environmental degradation is caused by the use of non-renewable energy consumptions for economic growth but the consequences of environmental degradation cannot be ignored.This primary purpose of this study is to investigate the nexus between energy consumption,economic growth and CO_(2) emission in Pakistan by using annual time series data from 1965 to 2015.The estimated results of ARDL indicate that energy consumption and economic growth increase the CO_(2) emissions in Pakistan both in short run and long run.Based on the estimated results it is recommended that policy maker in Pakistan should adopt and promote such renewable energy sources that will help to meet the increased demand for energy by replacing old traditional energy sources such as coal,gas,and oil.Renewable energy sources are reusable that can reduce the CO_(2) emissions and also ensure sustainable economic development of Pakistan.
文摘The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct and indirect consequences on ecologi-cal quality utilizing the environmental Kuznets curve(EKC)methodological approach.Our empirical analysis is based on the novel dynamic autoregressive distributed lag simulations approach for South Africa between 1960 and 2020.The results,which used five distinct financial development measures,demonstrate that financial develop-ment boosts ecological integrity and environmental sustainability over the long and short terms.In the instance of South Africa,we additionally confirm the validity of the EKC theory.More importantly,the outcomes of the indirect channels demonstrate that financial development increases energy usage’s role in causing pollution while attenuating the detrimental impacts of economic growth,trade openness,and foreign direct investment on ecological quality.Moreover,the presence of an inadequate financial system is a requirement for the basis of the pollution haven hypothesis(PHH),which we examine using trade openness and foreign direct investment variables.PHH for both of these variables disappears when financial development crosses specified thresholds.Finally,industrial value addition destroys ecological quality while tech-nological innovation enhances it.This research provides some crucial policy recom-mendations and fresh perspectives for South Africa as it develops national initiatives to support ecological sustainability and reach its net zero emissions goal.
基金financially supported by the National Natural Science Foundation of China(Nos.51874071 and 52022019)。
文摘In order to develop limonite and decrease CO_(2) emissions,siderite is proposed as a clean reductant for suspension magnetization roasting(SMR) of limonite.An iron concentrate(iron grade:65.92wt%,iron recovery:98.54wt%) was obtained by magnetic separation under the optimum SMR conditions:siderite dosage 40wt%,roasting temperature 700℃,roasting time 10 min.According to the magnetic analysis,SMR achieved the conversion of weak magnetic minerals to strong magnetic minerals,thus enabling the recovery of iron via magnetic separation.Based on the phase transformation analysis,during the SMR process,limonite was first dehydrated and converted to hematite,and then siderite decomposed to generate magnetite and CO,where CO reduced the freshly formed hematite to magnetite.The microstructure evolution analysis indicated that the magnetite particles were loose and porous with a destroyed structure,making them easier to be ground.The non-isothermal kinetic results show that the main reaction between limonite and siderite conformed to the two-dimension diffusion mechanism,suggesting that the diffusion of CO controlled the reaction.These results encourage the application of siderite as a reductant in SMR.
基金supported by Research and Community Service Program(P2MI)ITB.
文摘Carbon dioxide(CO_(2))is the main contributor to greenhouse gases that affect global warming.The industrial sector is the third largest producer of CO_(2) and the cement industry is one of the industries that consistently produces the most significant CO_(2) emissions.The cement industry produces 5-8% of global CO_(2) emissions.Several methods for reducing specific CO_(2) emissions have been reported in the cement industry,including calcium looping,which uses the reversible reaction between calcination[calcium carbonate(CaCO_(3))decomposition]and carbonation[CO_(2) capture by calcium oxide(CaO)].This work investigates calcium looping employing limestone obtained directly from several cement factories in Indonesia to observe the carbon-absorption characteristics of limestone from different mining locations.The experiment was carried out using a tube furnace equipped with a controlled atmospheric condition that functions as a calciner and a carbonator.X-ray diffraction and scanning electron microscopy with energy-dispersive x-ray spec-troscopy characterization were conducted to analyse the changes in the experimental samples.The results demonstrated that the reactor configuration was capable of performing the calcination process,which converted CaCO_(3) to calcium hydroxide[Ca(OH)_(2)],as well as the carbonation process,which captured carbon and converted it back to CaCO_(3).Parametric analysis was performed on both reactions,including pressure,temperature,duration,particle size and reaction atmosphere.The results show that the limestone obtained from all sites can be used as the sorbents for the calcium-looping process with an average reactivity of 59.01%.Limestone from cement plants in various parts of Indonesia has the potential to be used as carbon sorbents in calcium-looping technology.With a similar CO_(2) concentration as the flue gas of 16.67%,the experimental results show that Bayah limestone has the maximum reactivity,as shown by the highest carbon-content addition of 12.15 wt% and has the highest CO_(2)-capture capability up to>75% per mole of Ca(OH)_(2) as a sorbent.Similar levels of the ability to capture CO_(2) per mole of Ca(OH)_(2) can be found in other limestones,ranging from 14.85% to 34.07%.The results show a promising performance of raw limestones from different mining sites,allowing further study and observation of the possibility of CO_(2) emission reduction in the sustainable cement-production process.
文摘A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is studied.The considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming Potential.The main objective is the optimization of energy efficiency in order to minimize the environmental impact through the implementation of a sustainable strategy.It is shown that Exergy Analysis itself is a valuable tool in energy integration.Within the imposed framework of minimizing total annual costs,entropy analysis can be instrumental in determining the optimal plant concept,optimizing energy conversion and use,and improving profitability.The present results are discussed under the optimistic hope that they may help to define new energy and environmental policies.
