The economic feasibility of in-plant combustion of apple processing wastes

Reductions in fossil fuel and waste disposal costs could be achieved by apple processors through in-plant combustion of apple pomace. Life Cycle Costing techniques were employed to compare the average annual costs (prior to tax calculations) for investment in a handling/boiler system at 1983 prices. Operating conditions were representative of a small and large firm (producing 27 200 and 90 700 kg of pomace per day, respectively), which would combust all of the pomace generated. A loan of 14% annual interest with a 5-year payback period was assumed for the total fixed cost of each of three handling/boiler systems. The investment would be cost-effective for a small processor incurring 80% of disposal costs and for a large processor incurring 20% of disposal costs, with a fossil fuel price of $7·14 per gigajoule. The break-even point is most sensitive to waste flow rate, disposal cost and fossil fuel price.