Utilizing the heat content of gas-to-liquids by-product streams for commercial power generation

Abstract

The Gas-to-liquids (GTL) processes produce a large fraction of by-products whose disposal or handling ordinarily becomes a cost rather than benefit. As an alternative strategy to market stranded gas reserves, GTL provides middle distillates to an unsaturated global market and offers opportunities to generate power for commercial purposes from waste by-product streams, which normally are associated with increased expenses incurred from additional handling cost. The key concept investigated in this work is the possibility of integrating the GTL process with power generation using conventional waste by-product steam streams. Simulation of the integrated process was conducted with the aim of identifying the critical operating conditions for successful integration of the GTL and power generation processes. About 500 MW of electric power can be generated from 70% of the exit steam streams, with around 20 to 25% steam plant thermal efficiency. A detailed economic analysis on the LNG, stand-alone GTL, and Integrated GTL Power-Generation plants indicates that the integrated system is more profitable than the other options considered. Justifying the technology and economics involved in the use of the by-product streams to generate power could increase the net revenue and overall profitability of GTL projects. This technology may be transferable to GTL projects in the world, wherever a market for generated power exists.