Energy, exergy, and exergoeconomic analyses of plastic waste-to-energy integrated gasification combined cycles with and without heat recovery at a gasifier
B. Lee, Seong-kyun Im
Abstract
Energy, exergy, and exergoeconomic analyses were performed for two plastic-integrated gasification combined cycle (plastic-IGCC) systems to evaluate the performance of the plastic waste-to-energy cycles. Plastic waste-to-energy is a promising plastic treatment method that can resolve both plastic waste and environmental issues . Thus, improving the efficiency and economy of plastic-IGCC has become crucial because energy is generated during plastic waste-to-energy treatment while treating waste. The difference between the two modeled cycles is the location of heat recovery from the high-temperature syngas . In Cases 1 and 2, heat from the syngas was recovered with a heat recovery steam generator and a gas heater, respectively, to increase the temperature of the air entering the gasifier . The maximum net efficiency for Case 2 increased by 8.2% (from 35.41% to 43.57%), unlike that of Case 1, without changing exergy destruction . To assess the economic value and market potential, the unit electricity cost was examined for the condition in which the highest efficiency was obtained. The unit exergoeconomic costs for Cases 1 and 2 were 0.141 and 0.108 $/kWh, respectively, which were within the range of those in other energy recovery combined cycles; in addition, using air heaters for heat recovery reduced costs. The use of the air heater for heat recovery benefited energy and economic aspects without significantly changing exergy destruction . These findings have important implications for understanding the impact of gasifier agent conditions and energy recovery methods on the optimum conditions for plastic-IGCC. This study aimed to provide insights into the optimal design and operation of plastic-IGCC systems, considering both energy and economic aspects.