CO2 Capture Using Potassium-Based Solid Soebents and Subsequent Storage Using CH4 Replacement in Gas Hydrates

Abstract

The consumption of fossil fuels is increasing due to industrial development. As a results, the amount of CO2, which is produced from fossil fuel combustion and considered to be a representative greenhouse gas, is rapidly increasing. Thus, studies on the reduction, capture, and treatment of CO2 are being emphasized not only the energy field but also across entire industries. The concept of CO2 capture and storage technology is to capture the generated CO2 and sequestrate or store it instead of emitting it into the air. Generally, this method is called CCS (Carbon Capture and Storage). In this study, dry sorbent, which is regarded as innovative substance to reduce costs and energy, is used for CO2 capture. In addition, gas hydrate, which is found in the deep ocean sediments and have great potential as future energy resources, is used for CO2 storage. In case of CO2 capture, the CO2 carbonation-regeneration experiment was conducted using a dry sorbent in a bubbling fluidized bed reactor. As a result of changing the reaction conditions such as reaction temperature, with and without pretreatment and regeneration gas, they affected the absorption capacity of sorbent. In case of CO2 storage, the precise nature and unique pattern of CO2 swapping process in sH hydrates was investigated through macroscopic phase behavior and microscopic structure analyses. Neohexane and methylcyclopentane were used as liquid hydrocarbon for sH hydrate formation. It was found from structural and compositional analyses that initially formed sH hydrates were transformed into sI hydrates with increasing CO2 concentration in the hydrate phase. And the CO2 concentration where the structural transition occurs differs according to type of liquid hydrocarbon included. The results obtained in this study can be used as basic data for designing and operating a large scale CO2 capture process with two fluidized bed reactor and understanding the mechanism and possible structural transition of CH4-CO2 swapping process in sH hydrates.