Simulation of Ethane Recovery Process from Natural Gas via Gas Sub-cooled Process with Cold Separator in Iran’s South Persia Gas Complex

Heavy Ethane and Hydrocarbons of natural gas are separated via Gas Sub-cooled Process in South Persia phase 23 and produced under the title of Natural GasLiquid (NGL) product. On the basis of operational documents, the current procedure is able to recover the Ethane of 65/74 percent, in the best operational terms,from natural gas which is improper and we are witnesses of Ethane wasting in the process of gas waste. The main motivation of the present research is the significance ofEthane in petrochemical industry because refinery will obtain favorable interests with the increase of Ethane production and NLG. The purpose of the study issimulation of Ethane recovery unit in South Persia gas field on the basis of the new design entitled super-cooled gas by cold separator. For this purpose, the presentprocedure is simulated via Aspen HYSYS and Peng Robinson’s equation of state. In the new design, the output flow is phase separated from Joule-Thompsonvalve by a separator and enriched liquid phase is injected with Methane as a reflex to Methane-removal tower so that it can increase Ethane absorption and heavyHydrocarbons. The results of the new design simulation showed that the density of Ethane increased to 3 percent in NGL in relation to the current procedure. The newdesign based on the comparison which is made, reduced dew point of Hydrocarbons to -89 degree of centigrade and increases the rate NGL production to 1210 barrel perday.

Keywords:

Ethane recovery , simulation , GSP , Aspen HYSYS , NGL , Peng Robinson.