After a construction time of only six months, the anaerobic-digestion plant at Lanes Farm Energy near Pontefract went live last month, producing the first biomethane of the quality required by the UK gas distribution network.

Wolfgang Bokern, head of project management at the German biogas plant manufacturer Weltec Biopower (www.weltec-biopower.com), said: “We are very happy and proud to hand over this plant to our customer less than a year after signing the contract.”

The plant will now deliver around 7.3 million m3 a year of biomethane — enough to supply around 9,600 households with sustainable energy.

Food leftovers account for more than half of the 80,000tpa of substrate; the other ingredients include cattle and chicken manure, as well as grass silage and hybrid rye.

The solids are fed through two walking-floor feed hoppers and two MultiMix units to remove foreign objects and make them into an easily pumpable liquid.

This is fed from five tanks into four stainless-steel digesters (with a height of 8.8m), where the gas is produced.

The plant uses ‘membrane upgrading’ to transform the biogas into high-quality biomethane.

The biomethane production process also yields digestate, which is used as a high-quality fertiliser, returning organic material and nutrients to the land.

For this purpose, it’s first be pasteurised and separated.

The on-site electricity supply comes from an integrated 500kW combined heat and power system, which exports excess electricity to the grid.