Feasibility and performance analysis of utilizing spent mushroom substrate as biomass fuel

Abstract

A novel biomass system has been developed that utilizes spent mushroom substrates (SMS) and combines a pre-drying and drying system. The novel biomass system consists of a boiler and an Organic Rankine Cycle (ORC), which employs Isohexane as the working fluid to enable operation at high temperatures. The high moisture content of the SMS is dried by pre-drying from condensation waste heat of ORC and drying from the flue gas of the boiler to improve the calorific value of SMS. In the present study, the moisture content of the SMS and evaporation temperature of the ORC ranged from 50% to 65% and from 130℃ to 180℃. The results show although the thermal efficiency of ORC increased with an increase in evaporation temperature, the maximal output power is 412.21 kW at an evaporation temperature of 150 ℃. Additionally, when the moisture content of the SMS is 50 %, the thermal efficiency of the entire system approaches the maximal value (58.6%).