Track: Energy
Abstract
The brewery industry generates a lot of bio waste with potential for valorisation to bio energy. This study evaluated the possibility to produce environmentally friendly bio coal pellets from brewers spent grains through hydrothermal carbonisation technology. The bio coal pellets had a heating value of 26.1 MJ/Kg and a fixed carbon of 53.1% which were both higher than fossil coal. The bio coal also had a moisture content of 3.8%, ash content of 21.6% and volatile matter of 21.5%. The process designed had an energy integration system to use heat from the waste gases to reduce production costs. The total capital investment was USD 7.6 million, with the bio coal pellets production costs of USD 190.60 per tonne and a selling price of USD 200.00. The net present value was positive with a 21.7% return on investment and a payback period of 4.6 years.