Energy Recovery from Biosolids and Biomass A Review of Thermal Conversion Technologies

Melbourne Water investigated a broad variety of biosolids reuse options, including energy, fuel, chemical, nutrient, and metal recovery and reuse; use of biosolids as a geotechnical fill or building material extender; and for carbon sequestration. This paper focuses on those technologies capable of recovering energy, fuels, or non-nutrient chemicals from biosolids. Recognizing the higher energy content of other feedstocks and the potential benefits from taking advantage of capital installations' economies of scale, Melbourne Water also considered receiving foreign biomass at a potential future energy recovery plant, and hauling their biosolids to off-site facilities. Technologies investigated ranged from the most established, with hundreds of installations, to the most embryonic, that have only been tested in university laboratories. Maturity, scale, feedstock suitability, costs of facilities and market conditions for products were identified for each technology.