Efficient utilization of carbon dioxide in gas-to-liquids process: Process simulation and techno-economic analysis

Abstract Conceptual design of two options of carbon dioxide utilized gas-to-liquids process (CUGP), which mainly produces light olefins and Fischer–Tropsch (F–T) synthetic oils, has been implemented with the aid of Aspen Plus software. The mass and energy stream results as well as the process efficiencies and CO 2 emissions of the proposed options were obtained from the developed models. The capital investment and the product cost estimations were conducted before the following economic analysis. Several indicators such as net present value (NPV), discounted payback period (DPBP) and internal rate of return (IRR) were calculated to evaluate the profitability of the two proposed options. In the economic analysis, sensitivity analysis as well as break-even analysis was carried out. In addition, effects of several sensitive factors such as the prices of synthetic oil, olefin and natural gas, capital investment, carbon tax and plant scale on the IRR of each option were analyzed in detail. It was found that the CUGP, regardless of option, was economically feasible at the plant scale of 40,000 BPD and was more competitive compared with conventional GTL processes, in case of high carbon tax.