Assessment of a biomass-based polygeneration plant for combined power, heat, bioethanol and biogas

Abstract

A new polygeneration system utilizing biomass and composed of a biomass combustor, a Rankine power cycle, a biofuel production plant to produce bioethanol and biogas, and a district heating system for production of hot water, is proposed and investigated. Energy and thermodynamic analyses are conducted on the proposed system. Furthermore, a parametric analysis is carried out to determine the impacts of various significant design parameters including excess air ratio, pinch point temperature, and turbine inlet temperature and pressure on system energy efficiency and performance. The results show that the proposed system, at the design conditions, generates 35 MW power, 161 MW bioethanol, 76 MW biogas, and 90 MW district heating, with an energy efficiency of 73.0% for the combined heat and power portion of the plant and 63.0% for the overall polygeneration system.