Getting Into the Business of Biofuel
by Andrea Fox (Water Environment Federation/WEF Highlights) Most wastewater treatment plants do not support acres of sunflowers, rapeseed, or sorghum. However, a grant-funded pilot program at the Neuse River Wastewater Treatment Plant (Raleigh, N.C.) could interest some treatment plant managers in growing biofuel crops and defraying costs.
In 2010, the Biofuels Center of North Carolina (Oxford) gave the Neuse River plant a $100,000 grant to serve as a demonstration site to develop onsite oilseed production and biofuel processing. For 2 years, Neuse River has been growing grain and testing biofuel crops on the 405 ha (1000 ac) surrounding the plant.
Along with 2023 other municipal facilities in North Carolina, the plant has permits to land-apply biosolids and to use treated wastewater for irrigation. So, staff use stabilized solids as organic fertilizer and use treated wastewater for crop irrigation. While this minimizes agricultural costs, the ability to process biofuel onsite is the key to profitability, said Tim Woody, wastewater and reuse superintendent in the City of Raleigh Public Utilities Department.
…The oilseed system will be automated and could process 29 Mg/mo (32 ton/mo). The biofuel produced will be a component of B20 diesel blend, which contains 20% biodiesel and 80% petroleum and meets ASTM International (West Conshohocken, Pa.) fuel specifications. The fuel could provide half of the plant’s annual diesel needs of 94,625 L/yr (25,000 gal/yr) and also could help power city vehicles.
Woody has integrated biofuel processing with daily plant operations. “[It’s] a struggle for most plants with coproduction of another resource,” he said. “You need to be careful not to imbalance work schedules. We must not lose sight of the role of the wastewater operator. The time and effort needed to produce this biofuel must be a secondary effort.” READ MORE