Research on chemical looping combustion technology

LIU Tong; WANG Chen; SONG Yiwen; ZENG Dewang

Abstract：Chemical looping combustion is a novel fuel conversion technology that utilizes oxygen carriers to transfer oxygen between the gas and solid to achieve efficient fuel combustion and in-situ CO2 separation.The core of the tech-nology lies in the efficient design of oxygen carriers and reactors.However,the challenges include the low reactivity of oxygen carriers,which is easy to deactivation by sintering;the difficulty in coupling of the reactor and the fuel,and the optimized design and the industrial scale-up technology are not yet mature.Under such context,this paper reviews the research progress on the design and application of oxygen carriers and reactors in chemical looping combustion.Firstly,the current research status and design concepts of oxygen carriers are reviewed.Single metal oxides have a short preparation process and satisfactory high-temperature reactivity,but the stability is limited;multi-composite metal oxides optimize the anti-sintering ability by virtue of intermetallic synergistic effect,which significantly improves the reactivity and cyclic stability of the material.The use of industrial waste as an oxygen carrier shows both environmental and economic value;liquid carriers exhibit good high-temperature adaptability and mixing characteristics,but face cost and stability problems.Secondly,the research status of chemical looping combustion reaction device is introduced in detail,comparing the working principles,advantages and shortcomings of fluidized bed,fixed bed and rotating bed reactors,showing their adaptability to fuel type,reaction conditions and conversion characteristics.Fluidized bed reac-tors have good heat and mass transfer characteristics,but also require high physical properties of oxygen carriers.Fixed bed reactors are simple in structure,but heat transfer efficiency is limited in large-scale applications.Rotating bed re-actors are able to better combine the flexibility and efficiency of the system.Finally,the development and design of ox-ygen carrier and reactor are analyzed and outlooked to provide a basis for the subsequent chemical looping combus-tion technology to provide certain reference for the optimized design and engineering demonstration of the subse-quent chemical looping combustion technology.