HRS Heat Exchangers has won an order for its digestate concentration system (DCS) from Willen Biogas at an anaerobic digestion plant (AD) currently being constructed at Cattlegate Farm in Enfield, north London, which intends to take in the city’s food waste.
Farming business D Williams grows arable crops and herbs on more than 2,000 acres. It expects to save more than £90,000 a year in fertiliser costs by using the compost and digestate.
The DCS is a key part of utilising the nutrient-rich digestate effectively because it reduces the volumes produced while maintaining nutrient concentration. It reuses as much heat as possible, improving process efficiency of the entire AD plant.
HRS will provide a three-stage concentration system to take the liquid digestate, which has a low dry solid content, and increase the dry matter from around 4% to 9%. This cuts the overall volume of digestate produced, meaning that up to 60% less storage capacity is required and it can be applied with fewer operations.