The completion of the Anaerobic Digester (AD) ended a busy year at our Liverpool site. The AD plant will treat the main waste streams (trade effluent and food waste) produced by the UCO processing department along with some external food waste. The blended waste will be fed to a 2500m3 digester and will remain there for approximately 45 days during which time different groups of bacteria will break it down to produce biogas.
The biogas, which is 60% methane and 40% carbon dioxide, will run a 499kW CHP engine which will generate electricity and heat, both of which will be reused at the site. The energy from this process will significantly reduce our reliance on fossil fuels and will improve our carbon footprint. In addition, it will result in the UK’s (or even the World’s) first biodiesel plant that is run on energy generated from its own waste.
The AD plant was seeded with sewage sludge in December and successfully generated its first kWh of green electricity on the 19th December. This was a major milestone for the project as it was vital for Olleco to generate electricity before the 22nd December to ensure they received the Feed in Tariff incentive - a government programme designated to provide incentives for renewable technology.
The plan now is to follow a gradual feeding programme to allow the bacteria to acclimatise to the feedstock. Once this has happened, we will be able to increase the feedstock to its maximum load, which is 50-60 m3 per day. The next challenge will be to then optimise the process to ensure that they maximise the quantity of biogas generated.