A comparative simulation of a novel gas to liquid (GTL) conversion loop as an alternative to a certain refinery gas flare

Recently global attempt are focused on replacing gas flaring by environmentally friendly technologies, such as gas to liquid (GTL) technology. The main aim of this practice is preventing waste of energy and decreasing the emission of CO2 and other harmful by-product gases. In order to fulfill this goal, improvement of GTL process efficiency seems necessary. For this purpose, in this work the performance of two different configurations is compared in basis of hydrogen component. In both, refinery purge gases are used as a feedstock where enter to reaction side of a hydrogen perm-selective membrane reformer. In the first configuration, steam reformer reactor is located outside the Fischer-Tropsch synthesis loop while in the second one is placed inside the loop. A portion of generated hydrogen in the reformer is permeated through the membrane as a byproduct and the remaining is utilized in Fischer-Tropsch synthesis reactions. The simulation results of the aforementioned loops show that the second configuration is better than the first one of operation. The results of second configuration show 87% hydrogen utilization in F-T reactions and 11% hydrogen production in steam reformer reactions and also 2% hydrogen exit by off gas in separator. Further advantages of this alternative are namely, lessening in CO2 emission rate with a value of 0.8 for the first configuration ones and less than 0.33 to that of flaring, and more than 8430 barrels per day of heavy fraction hydrocarbons containing gasoline and butane fraction for a specified value (about 356.5 MMscfd) of purge gases. (c) 2012 Elsevier B.V. All rights reserved.