Production of synthetic gasoline and diesel fuel by alternative processes using natural gas and coal: Process simulation and optimization

The problem of producing synthetic liquid fuels by alternative routes is addressed. Industrial processes known as gas to liquid (GTL) and coal to liquid (CTL) are considered and compared to a hybrid process presently developed, which combines features of both GTL and CTL.Detailed process models are developed. Based on simulations, it is shown that the fuel produced per unit of feedstock (weight basis, with a productivity of 100 t/h of synthetic fuels) are 66.7% and 32.5% for GTL and CTL, respectively, and that the CO2 emitted per unit mass of liquid fuel is 0.63 kg CO2/kg for GTL and 4.66 kg CO2/kg for CTL. The hybrid process allows the production of 44.4% of fuel and to reduce CO2 emissions to 2.45 kg CO2/kg liquid fuel.By using pinch technology analysis (PTA) a heat integration of the hybrid process is carried out. From the results of PTA, no pinch point is found, a considerable amount of cooling water is needed, and the resulting thermal efficiency is around 55%.