I Gede Wibawa, Setiyo Gunawan : Cryogenic Freeze-Out Area Heat Exchanger As an Alternative Method of Liquifaction and CO2 Removal Unit at Small and Medium-Scale Liquified Natural Gas Plant
Prof.Dr.Ir. I Gede Wibawa M.Eng.
Setiyo Gunawan S.T., Ph.D
The presence of impurities such as carbon dioxide (CO2) in the natural gas can disturb the cryogenic process in the liquefaction of natural gas because CO2 would freeze at low temperatures. Therefore, the CO2 content should be eliminated according to the standard desired properties. CO2 removal unit are widely applied in industry is technology amines, membrane, pressure swing adsorption and controlled freeze zone. Currently, CO2 removal technologies being developed is Cryogenic Freeze-Out Heat Exchanger Area. This technology is an integrated cryogenic system between the melting and the removal of CO2 using a heat exchanger in which the purification process of impurities by setting the conditions so that impurities can freeze (frost) by utilizing the thermodynamic properties of mixtures of natural gas. Liquifaction utility can be done efficiently by using reversed-Brayton cycle in which nitrogen used as refrigerant. The aim of this study was to determine the performance of process equipment including operating conditions, and to predict the freezing of CO2 in the heat exchanger. Cost effective evaluation of operating and capital costs, where the data required in the calculation was obtained by process simulation. Formation and the rate of CO2 in the heat exchanger was predicted using a combination of mass transfer and energy equation in the heat exchanger. According to the cost effective, cryogenic freeze-out areas of heat exchangers had the prospects to be applied in the production of small and medium-scale LNG.