Proceedings

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.

KEYWORDS
Anaerobic digestion, biofertiliser, biogas, CHP, Dewaster, food waste, recycling, renewable
energy, resource conservation, thermal hydrolysis