Biofertiliser plant design – food waste to biofertiliser and biogas
This paper describes a plant that complies with Animal By-Products Regulations for Category II and III material. It will convert 30,000 tonnes food waste per year into bio-fertiliser, with a high degree of nutrient conservation, and biogas that will be used to generate electricity or could be processed to compressed natural gas, e.g. for automotive fuel. The design includes sustainable water management. The capital cost is approximately £7 million. The components have been selected and sized for reliability and longevity and to eliminate problems of litter, etc. that have plagued other plants. The annual operating cost is estimated at £0.86 million. The annual income from gate fees and electricity sales is approximately £2.6 million. The annual contribution is thus £1.8 million before taxes. Simplistically, this is a payback of approximately 4 years. In future, the capacity of plant could be increased readily at less than pro rata capital cost.