Thermo-economic analysis of energy recovery from municipal solid waste in an integrated plasma gasification combined cycle plant by modeling in aspen plus®

Abstract

ABSTRACT: Herein, the energy recovery from different MSW through an integrated plasma gasification combined cycle (IPGCC) power plant was investigated from an exergoeconomic viewpoint, using the Theory of Exergy Cost methodology. This study was conducted by an implemented model using Aspen Plus. MSWs that fuel the IPGCC power plant are produced in Medellín-Colombia, which are classified according to the sector considering their production rates and moisture contents (MC). Residential (1121 t/day and 57.9% of moisture content), Mixed (1468 t/day, 51.33%), Institutional (75 t/day, 37.92%), Commercial (168 t/day, 32.95%), and Industrial (104 t/day, 26.61%). Regarding the exergy analysis, for all plant cases, the plasma gasifier (PG) and the gas turbine (GT) reached the largest exergy destruction ratio, whose average contribution was 36.2% and 40.3%, respectively. This was ascribed to the exergy destruction by MSW drying into the PG, and by the oxidation reactions in the GT’s combustion chamber. Furthermore, as the MC of wastes increased (26.6% to 57.9%), the exergy destruction ratio of PG increased by 23.5%, leading to decrease the energy and exergy efficiencies of the IPGCC plants by 23.7% on average. This behavior was attributed to the adverse effect of high MC of wastes on the syngas quality. The exergy cost of electricity ranged from 11.0 to 14.5 ¢US$/kWh. Therefore, the plants with a processing capacity from 100 to 1000 t/day require a MSW treatment fee between 86.10 and 50.50 US$/t to equal the unit exergoeconomic cost of electricity with the hydro-electricity price in the Colombian energy market (6.92 ¢US$/kWh).