US firm Quasar Energy has completed a project at the Eastern Ohio Regional Wastewater Authority (EORWA) to help establish an energy-neutral facility. The new facility works by harvesting residual energy in wastewater processed at the plant along with organics from the region. It is hoped the project will help to stabilise the rate structure for its customers.
According to Waste Today Magazine, biosolids generated at the plant are listed as Class A/EQ quality and provide a replacement for commercial fertiliser for Ohio Valley farmers. These improvements are in line with EORWA’s sustainability goals.
To become an energy-neutral facility, EORWA introduced co-digestion to its plant. Traditionally food scraps and expired beverages generated in the Ohio Valley are sent to landfills. Now, these materials will be accepted with EORWA’s new liquids and solids-receiving equipment and mixed with sludge from the plant to be processed in anaerobic digesters to produce biogas. The biogas will then be converted into electricity with a microturbine that has enough capacity to offset 100% of the electrical use at the plant.
EORWA and Quasar entered into a biomass supply agreement where Quasar will manage the incoming biomass to the plant to provide smooth operations. It has the capacity to accept 27,000 wet tonnes per year. Tip fees from the material delivered, energy savings and lower biosolids disposal costs will help to offset the capital costs of the project.