Heat exchanger maker signed a $1.8 million contract with Scottish and Southern Energy to deliver a scraped surface vacuum evaporator for SSE's Barkip anaerobic digestion plant in North Ayrshire.

London-based HRS Heat Exchangers has signed a $1.8 million contract with Scottish and Southern Energy to deliver a scraped surface vacuum evaporator for SSE's Barkip anaerobic digestion plant in North Ayrshire. The HRS self-cleaning evaporator system overcomes the fouling issues associated with the evaporation of organic digestate, says the company.

The Barkip plant will be the first of its kind to incorporate a novel digestate processing stage: Waste heat from the combined heat and process (CHP) engines is used to concentrate the liquid fraction of the digestate into a nutrient rich liquid fertilizer. Under the terms of the contract, the HRS technology will enable the Barkip Anaerobic Digestion plant to process 82.6 short tons of waste annually in a plant setup that produces around 2.5 MW of renewable electricity.

HRS’ scraped surface heat exchanger will be used to help ensure any high organic load in contact with hot surfaces does not lead to fouling. Its Unicus Dynamic technology provides continuous cleaning to the walls of the HRS evaporator. The project was co-developed by Zebec Biogas, which has the specialist enzyme and biological process expertise.