A 5MW farmer-owned anaerobic digestion (AD) plant in Suffolk, UK, has selected HRS Heat Exchangers to supply a new system to pasteurise its digestate — the organic biofertiliser produced by the process.

Agri-Gen, which is based near Woodbridge in Suffolk, is owned by a consortium of six local farmers who locally grow some 22,000 acres of arable and root crops, such as potatoes, carrots, parsnips and sugar beet.

The AD plant is fed with a mixture of agricultural materials including rye, sugar beet, beet pulp, vegetable out-grades and maize, although the farms try to minimise the amount of maize grown.

The energy produced by the plant is used, amongst other things, to dry and cold store crops such as potatoes and onions.

Since it began producing biogas four years ago the company has focused on expanding and running the plant, but is now in a position to carry out a number of improvements to the process, including the additional of pasteurisation to improve the biosecurity of the digestate fertiliser which is returned to the farms’ fields.

This article first appeared on Bioenergy Insight on 22 January 2016.