Modelling of a novel electricity and methanol co-generation using heat recovery and CO2 capture: Comprehensive thermodynamic, economic, and environmental analyses

Abstract

The current investigation proposes a novel and efficient co-generation with a methanol production process through a power plant flue gas's captured CO2 in which an alkaline reactor supplies the methanol reactor's input hydrogen. Besides, the compressors, methanol distillation tower, and methanol reactor wasted heat are used as an Organic Rankine Cycle input energy to design a multi-layer wasted heat recovery system. The energy, exergy, economic and environmental approaches are used to assess the plant performance via an Aspen HYSYS code. Accordingly, the total energy and exergy efficiencies are obtained at about 64.13% and 76%. The CO2 capture and methanol separation unit efficiencies are estimated at 42% and 80%. Regarding exergy analysis, the methanol reactor has the highest exergy destruction of about 11302.61kW. The environmental assessment reveals that the total CO2 emission equals 0.9tonCO2/tonMeOH and the Organic Rankine Cycle utilization restricts the indirect emission to the reboilers and distillation columns. Eventually, the total annual cost and total production cost of the proposed scheme are calculated as about 5,638,060dollars and 0.73$/kgMeOH, respectively.