Prospects of GTL-Power Integration on a Modular GTL Plant.

Because of the capital intensiveness of gas-to-liquids (GTL) projects, much research has been focused on optimization to reduce the capital and operational cost, increase the efficiency, reduce the size and lower the emission levels associated with GTL technology processes. In this work, an effort to optimize the GTL plant has been proposed through the use of waste heat from produced steam in a typical modular GTL plant. The waste heat from the steam generated was used to simulate electricity production alongside the production of GTL diesel. The GTL plant was retrofitted with a steam turbine unit to handle the concurrent production of GTL fuels and electricity. The integrated GTL system was simulated in Unisim using the Peng-Robinson property package. A total of 220 MMscfd of medium pressure steam were produced from the synthesis gas and Fischer-Tropsch units. The integrated GTL plant produced 2534 b/d of GTL diesel and gasoline together with 4 MW of electricity. The economics analyses results show that the GTL liquids product alone yielded an NPV of US$231.8 million, with a payout time and internal rate of return (IRR) of 4.5 yrs and 22% respectively without the inclusion of an electricity generating unit. The integration of an electricity generating unit to the conventional GTL increased the profitability of the GTL project, an NPV of US$240.5 million was realized which translates to a percentage increase of 4%. The payout time and IRR for the GTL-Power coproduction were 3.3yrs and 30.2% respectively. Thus, there was a reduction in payout time of 0.67% and an increase in IRR of 0.91%. The enhanced GTL-Power co-production configuration has the potential to increase the profit realizable from the GTL project and should be considered an investment option. [ABSTRACT FROM AUTHOR]