Biochar and renewable energy generation from poultry litter waste: A technical and economic analysis based on computational simulations

Abstract

The technical and economic analysis of generating biochar together with electricity and/or heat from poultry litter (PL) waste is the subject of this study. To carry out this study, the process simulation software ECLIPSE is used. Modelling and simulation have been conducted over the selected system: the pyrolysis/gasification process integrated with an Organic Rankine Cycle (ORC). The facility will be capable of processing 1500kg of PL every hour. The simulation shows that when a reference PL is used the yield of biochar from the process is around 398kg/h with a 38% carbon content. Electricity generated by the ORC system is 388kWhe. Recovered low grade heat for space heating is estimated at 1831kWhth. The results of the economic analysis suggest that when paying £20/tonne for handling and storing the feedstock without any options of selling either heat or electricity, the break-even selling price (BESP) of biochar is around £218/tonne. If the sale of electricity and heat produced is considered to be around £60/MWhe and £5/MWhth, the BESP will decrease to £178/tonne. The case studies also indicate that when a gate fee of £10/tonne is introduced the BESP can be further reduced to £65/tonne, equivalent to a 63% reduction. On the other hand if biochar generated has an average price of £150/tonne in the market and the plant receives one Renewable Obligation Certificate (ROC) from the Government, the Levelised Cost of Electricity (LCOE) for the electricity generation will be £46/MWhe, which is compatible with electricity generated by fossil fuel power plants.