Fischer-Tropsch to Light Olefins Over Bimetallic Promoted Fe/Cnts Nanocatalyst: Techno-Economic and Life-Cycle Assessment

In this study, techno-economic analysis (TEA) and life cycle assessment (LCA) of light olefins production through Fischer-Tropsch (FT) synthesis were investigated in different scenarios. Aspen plus simulation and openLCA software were used to study process economics and green-house gas (GHG) emissions. Experimental data from a fixed-bed reactor via bimetallic promoted Fe-based nanocatalyst (0.5K5Mo10Fe/CNTs) were used to simulate a plant to produce 1 kg of ethylene/h. The economic feasibility of light olefins production was assessed via a detailed cash flow analysis. The net rate of return (NRR) calculated to 5.6%, 7.4%, and 18.2% for the base scenario (scenario 1), scenario 2 with wastewater treatment, and scenario 3 with wastewater treatment-separation unit, respectively, which means the project is economically profitable. From scenario 3, the minimum selling price of olefins is estimated to be 0.85 $/kg, which was about 11% lower than that of scenario 1. The sensitivity analysis carried out on all scenarios depicted that the operating costs were affected significantly by the raw materials, operating labor cost, and utilities. Effects of syngas feedstock rate on the economic performance of the suggested scenarios were evaluated in terms of the modified internal rate of return (MIRR) and total capital cost. A facility MIRR of 21.9% was obtained for scenario 3 and it was strongly influenced by syngas rate. The GHG emissions of scenario 1 was measured 77.5 g CO2-eq per MJ ethylene confirming a significant drop in GHG emissions compared to petroleum-based FT fuel production.