The SBU worked with the UK’s french fry manufacturing facility, located in Whittlesey, Peterborough, to reduce operating costs from the company’s waste treatment process.
The french fry factory produces a wastewater output rich in potato starch, which must be cleaned and treated before it’s properly discharged from the site.
The site’s wastewater treatment process includes a covered anaerobic lagoon (CAL) in its first stage, and CAL produces biogas as a by-product.
The CAL process allowed the completely packaged, biogas-fuelled CHP unit, of nominally 1MW electrical output, to burn the biogas and produce electricity.
The factory upgraded the facility by incorporating a gas scrubber to clean the sulphur from the biogas produced by the CAL and a gas booster plant to bring the gas supply pressure up to the level required for the gas-powered CHP unit.
The company said that the system reduces operating costs by displacing imported power and by qualifying for renewable obligation certificates (ROCs) which are tradable.
The capital investment in the gas system upgrade and the CHP installation was offset by the ROCs and displaced imported power cost, as it contributes up to 10% of the site’s annual electrical requirement.
