Solar hybridized coal-to-liquids via gasification in Australia: techno-economic assessment

The concept of solar hybridised coal-to-liquids is to produce transportation liquid fuels from the syngas obtained from gasification of carbonaceous feedstocks with the integration of concentrated solar thermal power (CSP). In the present study, a techno-economic evaluation of a coal-to-liquids processes integrated with a solar hybridised, oxygen blown, atmospheric pressure vortex-flow gasifier (SCTL) is compared with that of a reference, non-solar, pressurised entrained flow gasifier (CTL) based on the solar and coal resources in Australia. In comparison with conventional gasification systems, the proposed SCTL system reduces the input feedstock by 18% while maintaining the Fischer-Tropsch (FT) liquids output. Furthermore, with the addition of CSP to the CTL plant, a reduction in mine-to-tank (MTT) CO2 emissions by 26% can be achieved. This is due to the fact that the heat required to meet the endothermic gasification reactions is supplied by CSP when the sun is available, thus more coal was converted to syngas subsequently higher FT liquids. To produce 1500 barrel per day of FT liquids, the total permanent investment cost for the SCTL plant was estimated to be around $ 467-$ 493 million, depending on the solar site and the coal compared with the CTL plant of around $ 377-$ 384 million if the plant was to be built in year 2020. The levelised cost of fuel (LCOF) for the CTL plants was found to be around $ 40-$ 41/GJ(LHV) and $ 46-$ 49/GJ(LHV) for the SCTL plants. The LCOF for the plants is very sensitive to the total permanent investment cost, load factor and cost of carbon capture and sequestration. Furthermore, the LCOF for the SCTL plant is also very sensitive to the cost of the syngas storage. (C) 2015 The Authors. Published by Elsevier Ltd.