Biosolids to Bioenergy — New Facilities Will Build on Old Ideas

Sustainable management of wastewater treatment plant residuals remains a key challenge for wastewater utilities across North America. Beneficial use practices to date such as composting and land application are facing significant challenges due to rising costs, regulatory uncertainty and public opposition. Utilizing biosolids as a renewable energy fuel is increasing in importance due to the growing awareness of climate change, volatile and rising costs of fossil fuel derived energy and a need to gradually transition towards a “green” economy. Biosolids offer opportunities for municipal wastewater treatment plants (WWTPs) and agencies to gain energy independence, reduce overall operating costs and control increase of customer fees.The presentation will discuss findings from feasibility studies completed by the authors for several biosolids-to-energy (B2E) facilities across the United States. The studies assessed new and innovative B2E technologies on a preliminary basis and compared with more conventional thermal hydrolysis and thermal oxidation technologies involving energy recovery. Technical, economic, environmental and modular attributes of potential technologies were assessed, with emphasis on whether the technology had been proven at some scale or proven in another application.