Production of Bio-Coke from spent mushroom substrate for a sustainable solid fuel

Abstract

Spent mushroom substrate (SMS), defined as the residual biomass after mushroom cultivation, has been known to cause serious pollution, especially river pollution, as it is produced in large quantities and has been disposed of without consideration of the environment. Thus, there is growing interest in converting this biomass waste into Bio-Coke as an alternative solid fuel to be used in a boiler to generate steam for mushroom substrate pasteurization. This study analyzes the physical characteristics of Bio-Coke conversion from SMS in Malaysia, and it was found to have better physical characteristics than other types of conventional biomass fuel. The results indicate that Bio-Coke from SMS at a formation temperature of 170 °C had an apparent density of 1.397 g/cm3 and a combustion period of 1890 s. Its maximum compressive strength at room temperature (25 °C) and 700 °C was 105.2 and 5.302 MPa, respectively, which is ideal for a biomass solid fuel. Its high apparent density and mechanical strength provide evidence that SMS Bio-Coke is structurally robust and can remain intact when compressed at high pressure and burned at high temperature in a boiler. Thus, the use of SMS Bio-Coke presents itself as a potential strategy for biomass waste management in Southeast Asia, particularly Malaysia. Trial registration number: Date of registration “retrospectively registered”.