Preliminary investigation on the use of biogas sludge for gasification

This paper addresses preliminary investigations into the use of digester sludge briquettes for gasification and engine application. Results from basic studies related to flaming and glowing time carried out on the briquettes spheres compare well with the wood spheres on an ash-free basis. Specific investigations to understand the behaviour of this material in a packed bed to evaluate ash fusion property under varying mass flux, suggests a maximum flux of 0.17 kg m−2 s−1. Experimental studies using an open top dual air entry gasifier resulted in a consistent gas composition with a calorific value in the range of 4.2 MJ kg−1 and a cold gas efficiency of 72%. Suitability of the gas for engine operation was carried out using a gas engine rated for of 25 kW capacity. Gas engine operations have indicated a maximum output of 23 kW with specific fuel consumption ∼ 1.65±0.1 kg kWh−1.