化石燃料的大规模使用造成了CO_(2)排放量逐年递增,其作为温室气体的主要成分加速了全球变暖及气候变化。CO_(2)的捕集、利用与存储(Carbon Capture,Utilization and Storage,简称CCUS)技术作为降低碳排放的有效方法,受到广泛关注。在...化石燃料的大规模使用造成了CO_(2)排放量逐年递增,其作为温室气体的主要成分加速了全球变暖及气候变化。CO_(2)的捕集、利用与存储(Carbon Capture,Utilization and Storage,简称CCUS)技术作为降低碳排放的有效方法,受到广泛关注。在诸多减少CO_(2)排放量的方法中,吸附法分离脱除CO_(2)具备良好的应用前景。固体吸附材料具有操作温度广、不易腐蚀设备、循环使用过程中产生的废物较少且易于处理等优点,被认为是理想的CO_(2)捕集材料。综述了3种类型的CO_(2)固体吸附剂的研究进展,包括低温、中温和高温固体吸附剂,指出了其优点和局限性及强化CO_(2)吸附性能与循环稳定性的措施。通常来说高压对低温固体吸附剂更加有利,但此条件下其选择性较差,且气流中存在的水分会水解某些吸附剂中的配位键,并与CO_(2)产生竞争吸附,导致CO_(2)吸附性能下降。因此低温吸附剂的吸附能力、吸附选择性和水热稳定性是研究重点。中温固体吸附剂中,类水滑石材料面临的挑战在于其独特的氢键堆积结构限制了其吸附容量进一步提高,而MgO吸附剂由于缺少基础活性位点以及固有的高晶格焓同样导致其吸附性能与吸附动力学较差。故中温吸附剂需要优先解决其低吸附能力和低循环稳定性的问题。高温固体吸附剂中,Li_(4)SiO_(4)吸附剂相比于Li_(2)ZrO_(3)吸附剂具备更低的制备成本以及更高的吸附容量,但2者皆面临动力学限制问题。CaO基吸附剂由于其理论吸附容量高、适用范围广、成本低廉、无毒、具备快速的吸附动力学特性等优点受到广泛关注。而在CO_(2)吸附/脱附多循环过程中,钙基吸附剂由颗粒烧结引发的热失活以及颗粒磨损问题是限制其进一步发展的最大障碍。针对这些问题可采用高温预处理、水合作用、化学掺杂、酸改性等方式来提高其吸附性能与多循环稳定性。此外展开更多
Coupling electrochemical CO_(2)reduction(CO_(2)R)with a renewable energy source to create high‐value fuels and chemicals is a promising strategy in moving toward a sustainable global energy economy.CO_(2)R liquid pro...Coupling electrochemical CO_(2)reduction(CO_(2)R)with a renewable energy source to create high‐value fuels and chemicals is a promising strategy in moving toward a sustainable global energy economy.CO_(2)R liquid products,such as formate,acetate,ethanol,and propanol,offer high volumetric energy density and are more easily stored and transported than their gaseous coun-terparts.However,a significant amount(~30%)of liquid products from electrochemical CO_(2)R in a flow cell reactor cross the ion exchange membrane,leading to the substantial loss of system‐level Faradaic efficiency.This severe crossover of the liquid product has—until now—received limited attention.Here,we review promising methods to suppress liquid product crossover,including the use of bipolar membranes,solid‐state electrolytes,and cation‐exchange membranes‐based acidic CO_(2)R systems.We then outline the re-maining challenges and future prospects for the production of concentrated liquid products from CO_(2).展开更多
Amines are well-known for their reversible reactions with CO_(2),which make them ideal for CO_(2) capture from several gas streams,including flue gas.In this respect,selective CO_(2) absorption by aqueous alkanolamine...Amines are well-known for their reversible reactions with CO_(2),which make them ideal for CO_(2) capture from several gas streams,including flue gas.In this respect,selective CO_(2) absorption by aqueous alkanolamines is the most mature technology but the process is energy intensive and has also corrosion problems.Both disadvantages can be diminished to a certain extent by chemical adsorption of CO_(2) selectively.The most important element of the chemical adsorption of CO_(2) involves the design and development of a suitable adsorbent which consist of a porous support onto which an amine is attached or immobilized.Such an adsorbent is often called as solid amine sorbent.This review covers solid amine-based studies which are developed and published in recent years.First,the review examines several different types of porous support materials,namely,three mesoporous silica(MCM-41,SBA-15 and KIT-6)and two polymeric supports(PMMA and PS)for CO_(2) adsorption.Emphasis is given to the synthesis,modifications and characterizations-such as BET and PXRD data-of them.Amination of these supports to obtain a solid amine sorbent through impregnation or grafting is reviewed comparatively.Focus is given to the adsorption mechanisms,material characteristics,and synthesis methods which are discussed in detail.Significant amount of original data are also presented which makes this review unique.Finally,relevant CO_(2) adsorption(or equilibrium)capacity data,and cyclic adsorption/desorption performance and stability of important classes of solid amine sorbents are critically reviewed.These include severa PEI or TEPA impregnated adsorbents and APTES-grafted systems.展开更多
文摘化石燃料的大规模使用造成了CO_(2)排放量逐年递增,其作为温室气体的主要成分加速了全球变暖及气候变化。CO_(2)的捕集、利用与存储(Carbon Capture,Utilization and Storage,简称CCUS)技术作为降低碳排放的有效方法,受到广泛关注。在诸多减少CO_(2)排放量的方法中,吸附法分离脱除CO_(2)具备良好的应用前景。固体吸附材料具有操作温度广、不易腐蚀设备、循环使用过程中产生的废物较少且易于处理等优点,被认为是理想的CO_(2)捕集材料。综述了3种类型的CO_(2)固体吸附剂的研究进展,包括低温、中温和高温固体吸附剂,指出了其优点和局限性及强化CO_(2)吸附性能与循环稳定性的措施。通常来说高压对低温固体吸附剂更加有利,但此条件下其选择性较差,且气流中存在的水分会水解某些吸附剂中的配位键,并与CO_(2)产生竞争吸附,导致CO_(2)吸附性能下降。因此低温吸附剂的吸附能力、吸附选择性和水热稳定性是研究重点。中温固体吸附剂中,类水滑石材料面临的挑战在于其独特的氢键堆积结构限制了其吸附容量进一步提高,而MgO吸附剂由于缺少基础活性位点以及固有的高晶格焓同样导致其吸附性能与吸附动力学较差。故中温吸附剂需要优先解决其低吸附能力和低循环稳定性的问题。高温固体吸附剂中,Li_(4)SiO_(4)吸附剂相比于Li_(2)ZrO_(3)吸附剂具备更低的制备成本以及更高的吸附容量,但2者皆面临动力学限制问题。CaO基吸附剂由于其理论吸附容量高、适用范围广、成本低廉、无毒、具备快速的吸附动力学特性等优点受到广泛关注。而在CO_(2)吸附/脱附多循环过程中,钙基吸附剂由颗粒烧结引发的热失活以及颗粒磨损问题是限制其进一步发展的最大障碍。针对这些问题可采用高温预处理、水合作用、化学掺杂、酸改性等方式来提高其吸附性能与多循环稳定性。此外
文摘Coupling electrochemical CO_(2)reduction(CO_(2)R)with a renewable energy source to create high‐value fuels and chemicals is a promising strategy in moving toward a sustainable global energy economy.CO_(2)R liquid products,such as formate,acetate,ethanol,and propanol,offer high volumetric energy density and are more easily stored and transported than their gaseous coun-terparts.However,a significant amount(~30%)of liquid products from electrochemical CO_(2)R in a flow cell reactor cross the ion exchange membrane,leading to the substantial loss of system‐level Faradaic efficiency.This severe crossover of the liquid product has—until now—received limited attention.Here,we review promising methods to suppress liquid product crossover,including the use of bipolar membranes,solid‐state electrolytes,and cation‐exchange membranes‐based acidic CO_(2)R systems.We then outline the re-maining challenges and future prospects for the production of concentrated liquid products from CO_(2).
基金This work has been supported by Turkish Scientific and Technological Research Council(Project Number:111A016).Authors gratefully acknowledge the financial support.
文摘Amines are well-known for their reversible reactions with CO_(2),which make them ideal for CO_(2) capture from several gas streams,including flue gas.In this respect,selective CO_(2) absorption by aqueous alkanolamines is the most mature technology but the process is energy intensive and has also corrosion problems.Both disadvantages can be diminished to a certain extent by chemical adsorption of CO_(2) selectively.The most important element of the chemical adsorption of CO_(2) involves the design and development of a suitable adsorbent which consist of a porous support onto which an amine is attached or immobilized.Such an adsorbent is often called as solid amine sorbent.This review covers solid amine-based studies which are developed and published in recent years.First,the review examines several different types of porous support materials,namely,three mesoporous silica(MCM-41,SBA-15 and KIT-6)and two polymeric supports(PMMA and PS)for CO_(2) adsorption.Emphasis is given to the synthesis,modifications and characterizations-such as BET and PXRD data-of them.Amination of these supports to obtain a solid amine sorbent through impregnation or grafting is reviewed comparatively.Focus is given to the adsorption mechanisms,material characteristics,and synthesis methods which are discussed in detail.Significant amount of original data are also presented which makes this review unique.Finally,relevant CO_(2) adsorption(or equilibrium)capacity data,and cyclic adsorption/desorption performance and stability of important classes of solid amine sorbents are critically reviewed.These include severa PEI or TEPA impregnated adsorbents and APTES-grafted systems.
