Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typ...Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies.展开更多
Asphalt modifications either involved commercial or recycled waste materials modifiers help optimise and improve the deficient properties of asphalt mixtures relative to current standards.This manuscript reviews the r...Asphalt modifications either involved commercial or recycled waste materials modifiers help optimise and improve the deficient properties of asphalt mixtures relative to current standards.This manuscript reviews the recycling of waste materials generated from various sources such as household,agricultural and industrial to minimise natural resources exploitation,lower energy demand,and enhance overall pavement performance.The actual development and implementation of recycled asphalt pavement in numerous countries in Asia,North America,South America,Europe and Africa are emphasised,and their influence on the performance of asphalt pavements is reviewed.Modified pavement showed satisfying performance for years as maintenance and restoration are not required.Generally,solid wastes are required to undergo pre-requisite treatments via mechanical,biological stabilization,thermal or chemical methods before the implementation as asphalt modifiers to ease the handling process.Moisture damage issues have been spotted in the implementation of several types of solid wastes and consequently reduced the strength and durability of pavement.Therefore,potential hydrophobic treatment can be adopted to improve the quality of asphalt mixtures by modifying the hydrophilic characteristics that are contributed by the hydroxyl groups on the cellulose nanocrystals(CNCs)or providing a superhydrophobic coating onto the particles.The treatments greatly weakened the moisture sensitivity of modified materials by reducing their water absorption and increasing their water contact angle.The modified mixtures are necessary to have identical or enhanced pavement performance to the conventional mixtures.Besides,future researchers are encouraged to broaden the research field in pavement engineering by considering chemical treatments in improving material properties to achieve cost-saving,efficient waste management,and higher commercial feasibility.Before implementing any virgin materials,waste materials and by-products as alternative substances or modifiers,it is strongly advised to consider the environmental and economic impacts of the material properties and their optimal incorporation.展开更多
我国多煤少油的能源禀赋,决定了煤炭是使用最多的化石能源。大量煤炭用于燃料产生巨量的二氧化碳排放,加剧了我国实现碳达峰、碳中和目标的难度。自2010年以来,我国电力行业不断优化调整,火力发电比例和火电装机容量占比都在持续下降,...我国多煤少油的能源禀赋,决定了煤炭是使用最多的化石能源。大量煤炭用于燃料产生巨量的二氧化碳排放,加剧了我国实现碳达峰、碳中和目标的难度。自2010年以来,我国电力行业不断优化调整,火力发电比例和火电装机容量占比都在持续下降,非化石能源发电比例逐年上升。尽管火电占比逐年减少,但其在我国电力能源结构中的主导地位仍无法改变。对中国碳核算数据库China Emission Accounts and Datasets(CEADs)的数据进行分析,2020年我国电力行业碳排放46.24亿t,占当年总碳排放量42.21%。电力行业的发展关系国计民生,是国民经济的支柱。在相当长的历史时期,煤炭在我国能源结构中都占据主导地位。在能源需求稳健上涨的背景下,煤电成为我国能源电力稳定供应的“压舱石”,在短期内很难被其它能源完全取代。目前煤电行业碳减排主要采取节能与提高能效比、燃料掺烧、碳捕集、利用与封存(CCUS)技术及二氧化碳矿化技术。结合电厂的实际碳排放情况及目前CCUS技术成熟度来看,生物质能结合碳捕集与封存技术与间接矿化技术是目前电厂可行的实现碳中和的方案。但生物质能结合碳捕集与封存技术需要对原有的锅炉进行混烧改造,目前我国在生物质发电技术仍存在很多不足,尤其体现在生物质燃料的收集、运输、加工、储存等特殊辅助机械的开发配套方面。对于煤电行业碳中和技术的发展,根据我国的实际情况,建议采用中长期的碳捕集利用技术路线,应同步开展燃烧前捕集技术、富氧燃烧技术及燃烧后捕集技术的技术创新、研发低成本、高效率技术体系并商业化应用。展开更多
基金support was received the Science&Technology Foundation of RIPP(PR20230092,PR20230259)the National Natural Science Foundation of China(22278419)the Key Core Technology Research(Social Development)Foundation of Suzhou(2023ss06).
文摘Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies.
基金Universiti Sains Malaysia for the financial support via Research University Individual(RUI)Grant(1001.PAWAM.8014140)to conduct this research work.
文摘Asphalt modifications either involved commercial or recycled waste materials modifiers help optimise and improve the deficient properties of asphalt mixtures relative to current standards.This manuscript reviews the recycling of waste materials generated from various sources such as household,agricultural and industrial to minimise natural resources exploitation,lower energy demand,and enhance overall pavement performance.The actual development and implementation of recycled asphalt pavement in numerous countries in Asia,North America,South America,Europe and Africa are emphasised,and their influence on the performance of asphalt pavements is reviewed.Modified pavement showed satisfying performance for years as maintenance and restoration are not required.Generally,solid wastes are required to undergo pre-requisite treatments via mechanical,biological stabilization,thermal or chemical methods before the implementation as asphalt modifiers to ease the handling process.Moisture damage issues have been spotted in the implementation of several types of solid wastes and consequently reduced the strength and durability of pavement.Therefore,potential hydrophobic treatment can be adopted to improve the quality of asphalt mixtures by modifying the hydrophilic characteristics that are contributed by the hydroxyl groups on the cellulose nanocrystals(CNCs)or providing a superhydrophobic coating onto the particles.The treatments greatly weakened the moisture sensitivity of modified materials by reducing their water absorption and increasing their water contact angle.The modified mixtures are necessary to have identical or enhanced pavement performance to the conventional mixtures.Besides,future researchers are encouraged to broaden the research field in pavement engineering by considering chemical treatments in improving material properties to achieve cost-saving,efficient waste management,and higher commercial feasibility.Before implementing any virgin materials,waste materials and by-products as alternative substances or modifiers,it is strongly advised to consider the environmental and economic impacts of the material properties and their optimal incorporation.
文摘我国多煤少油的能源禀赋,决定了煤炭是使用最多的化石能源。大量煤炭用于燃料产生巨量的二氧化碳排放,加剧了我国实现碳达峰、碳中和目标的难度。自2010年以来,我国电力行业不断优化调整,火力发电比例和火电装机容量占比都在持续下降,非化石能源发电比例逐年上升。尽管火电占比逐年减少,但其在我国电力能源结构中的主导地位仍无法改变。对中国碳核算数据库China Emission Accounts and Datasets(CEADs)的数据进行分析,2020年我国电力行业碳排放46.24亿t,占当年总碳排放量42.21%。电力行业的发展关系国计民生,是国民经济的支柱。在相当长的历史时期,煤炭在我国能源结构中都占据主导地位。在能源需求稳健上涨的背景下,煤电成为我国能源电力稳定供应的“压舱石”,在短期内很难被其它能源完全取代。目前煤电行业碳减排主要采取节能与提高能效比、燃料掺烧、碳捕集、利用与封存(CCUS)技术及二氧化碳矿化技术。结合电厂的实际碳排放情况及目前CCUS技术成熟度来看,生物质能结合碳捕集与封存技术与间接矿化技术是目前电厂可行的实现碳中和的方案。但生物质能结合碳捕集与封存技术需要对原有的锅炉进行混烧改造,目前我国在生物质发电技术仍存在很多不足,尤其体现在生物质燃料的收集、运输、加工、储存等特殊辅助机械的开发配套方面。对于煤电行业碳中和技术的发展,根据我国的实际情况,建议采用中长期的碳捕集利用技术路线,应同步开展燃烧前捕集技术、富氧燃烧技术及燃烧后捕集技术的技术创新、研发低成本、高效率技术体系并商业化应用。
