Optimal Operation Of Multiple Cryogenic Bed Network For Purification Of Malaysian Natural Gas

Natural gas processing consists of separating all of the various hydrocarbons and impurities from the wellhead gas, to produce what is known as 'pipeline quality' dry natural gas. The present study investigates the optimal conditions for the multiple cryogenic packed beds network which separates water, carbon dioxide and heavy hydrocarbons from high pressure natural gas. The working principle of multiple cryogenic packed beds network is based on the difference in desublimation temperature of each component in natural gas. In general, the separation process involves three cycles, namely cooling cycle, capture cycle and regeneration cycle. During cooling cycle, refrigerant is used to cool the packed bed. When the packed bed is cooled to a desired temperature, which is below the desublimation temperature of the component to be removed, for instance carbon dioxide, natural gas feed is introduced into the packed bed and the capture cycle began. When the bed reaches its saturation point and is no longer efficient in capturing carbon dioxide, the refrigerant flow is cut off in order to regenerate the packed bed by utilizing hot air or hot carbon dioxide flow to vaporize the solid carbon dioxide that formed on the solid packing surface. In present study the optimal temperature and pressure conditions for natural gas processing are explored. For natural gas feed of 40% carbon dioxide, multiple cryogenic packed beds network with optimal pressure and temperature combinations is able to produce methane gas with 92% purity.