Syntroleum in GTL study

Abstract

The conversion of natural gas at its source to higher-valued liquid fuels is an alternative to the pipeline transportation of treated gas and the dedicated tanker shipping of LNG. This IEA study investigated the effects of reducing carbon emissions from gas-to-liquid (GTL) plants for such remote applications. Three different Fischer-Tropsch GTL plant configurations with characteristics similar to those of Sasol, Shell, and Syntroleum were examined. These three configurations are selected because they cover the major types of GTL technologies currently considered to be either commercially viable or under development.The design of each of these FT- based GTL plants was based on published information. The purity of the captured CO2 was better than 95% and is suitable for on-site injection. Plant investment and operating costs were developed from the Bechtel in-house database. The licensors were asked to comment on the results of this study and their comments were included in the Appendix of the study report.Three steps are generally taken in the task of carbon-emissions abatement: (1) select appropriate carbon-capture technology, (2) identify the location in the process configuration for optimum carbon removal, and (3) modify the process configuration to maximize carbon utilization in liquid fuel products and minimize carbon emission. For each GTL technology, a base case was developed to determine the baseline carbon emissions and the capital and operating cost, prior to CO2 abatement. The plant was then redesigned to achieve at least 85% reduction in CO2 emissions, with the capital and operating cost determined as before.The CO2 capture technologies investigated here were limited to the commercially-proven processes, such as chemical absorption (amine solutions, etc.), physical adsorption (molecular sieve), and cryogenic separation. Combustion of hydrocarbon fuels in process heating or flaring was minimized to limit CO2 emissions from the GTL plant.