Proposal of an environmental-friendly poly-generation model regarding the flue gas processing for the production of electricity, cooling, heating, freshwater, and methanol

Abstract

In this paper, a novel poly-generation system with high thermodynamic performance and low carbon dioxide (CO2) emission is presented and analyzed from the 4E (energy, exergy, economic, and environmental) perspective. The newly designed structure consists a gas turbine cycle, transcritical CO2 cycles, a Kalina power cycle, a water desalination unit, a methanol production unit, and a chiller. Toward this goal, the flue gas leaving the gas turbine cycle is processed and utilized. Thermodynamic analysis demonstrates that the total energy and exergy efficiencies are attainable at 58.75% and 69.46%, respectively. In addition, the total exergy destruction rate equals 183105 kW in which the gas turbine cycle is the major source of irreversibility with a share of 51%. In addition, exergy analysis indicates that the combustor of the gas turbine cycle has the highest exergy destruction ratio (44.54%) among all equipment. Regarding the environmental aspect, the total CO2 emission and its emission intensity for the proposed process are 18678.42 kgCO2/h and 0.75 kgCO2/kgMeOH, respectively. Its indirect emission is responsible for 48.8% of the total emission as well. Attributable to the thermo-environmental results, the proposed process has a suitable performance compared to similar technologies. The economic analysis demonstrated that its total annual cost equals 60800563 $ and production costs of methanol, freshwater, heating, cooling, and power are 0.3 $/kgMeOH, 0.43 $/kgfreshwater, 0.16 $/kgLPS, 0.022 $/kgchilled water, and 0.069 $/kWh, respectively.