THE team behind an award-winning anaerobic digester plant has saved money by choosing a British company to supply its gas analysis equipment.
Fernbrook Bio uses food waste from local authorities and other outlets to produce electricity through the AD process. Its Rothwell Lodge biogas plant near Kettering accepts 30,000 tonnes of segregated food wastes from homes and businesses in the surrounding area and won the Best Anaerobic Digestion Project 2012 at the first UK AD & Biogas Industry Awards.
Initially, a gas analyser was installed as part of the construction of the plant, but when it was due to be serviced, site manager Carl Woolley was in for a shock.
He explained: “The gas analyser was supplied by a German company and when it came to having an annual service we were quoted a price which meant after 2-3 years we could have bought a completely new system. It just wasn’t practical.
“We looked at the market and different types of analyser and we liked the idea of the Gas Data Click! System where we can just change small parts as required instead of larger more expensive ones. We are able to get the unit serviced locally, the parts are smaller and easier to change and I am able to manually select which sample point I want to test.”
Gas analysis is crucial to Fernbrook’s business. “The digesters are just like giant stomachs,” added Woolley. “If you over-feed them the gas quality drops and if you under-feed them the gas quality goes up. This fluctuation can cause problems with the Combined Heat and Power (CHP) engines, so we need gas analysers to help us maintain the engine performance.
“If our methane quality changes too much our CHPs can’t cope and then turn off, so we lose power generation – and money. Also, if our hydrogen sulphide (H2S) content is too high, it creates more wear on the engines and our service costs get higher.”
Fernbrook now has two digesters on site and planning permission for a third so it can increase the site capacity to 45,000 tonnes a year.