"Abstract
This paper is aimed at developing process alternatives of conventional coal gasification. A number of possibilities are presented, simulated, and discussed in order to improve the process performances, to avoid the use of pure oxygen, and to reduce the overall CO2 emissions. The different process configurations considered include both power production, by means of an integrated gasification combined cycle (IGCC) plant, and synfuel production, by means of Fischer−Tropsch (FT) synthesis. The basic idea is to thermally couple a gasifier, fed with coal and steam, and a combustor where coal is burnt with air, thus overcoming the need of expensive pure oxygen as a feedstock. As a result, no or little nitrogen is present in the syngas produced by the gasifier; the required heat is transferred by using an inert solid as the carrier, which is circulated between the two modules. First, a thermodynamic study of the dual-bed gasification is carried out. Then a dual-bed gasification process is simulated by Aspen Plus, and the efficiency and overall CO222 emissions per unit of liquid fuel are decreased by 31.9% and energy efficiency increases by 71.1%." emissions of the process are calculated and compared with a conventional gasification with oxygen. Eventually, the scheme with two reactors (gasifier-combustor) is coupled with an IGCC process. The simulation of this plant is compared with that of a conventional IGCC, where the gasifier is fed by high purity oxygen. According to the newly proposed configuration, the global plant efficiency increases by 27.9% and the CO emissions decrease by 21.8%, with respect to the performances of a conventional IGCC process. As a second possibility, the same gasifier−combustor scheme is coupled with a coal-to-liquid (CTL) process to convert the syngas into synthetic fuels by a FT reactor. It is shown that, if compared with a conventional CTL plant, the mass yield of liquid synthetic fuel is increased by 39.4%, the CO
The Italians, Mike. They don't have all that much coal. Why not WV?