RECYCLING AND ENERGY RECOVERY FROM INCONTINENCE WASTE (INKOCYCLE): ANAEROBIC TREATMENT OF ADULTS DIAPERS

摘要

Due to the demographic change in Europe, the amount of incontinence waste is expected to increaserndrastically. In Germany, this waste stream is estimated as 200,000 metric tonnes per year. This study focused on thernoptimized energy recovery from incontinence waste using a combined approach of anaerobic digestion (AD) of thernorganics fraction followed by incineration of the digestate as refuse derived fuel (RDF). In a two years pilot test thernAD resulted in 238 L biogas / patient and day with an average composition of 56 % CH_4 and 44 % CO_2. Based on thernoriginal waste the gas yield is 155 L biogas per kg of used diapers. The digestion residue mostly consists of the nonbiodegradablernplastic components, adhering biomass and the superabsorbent polymer. The calorific value of thernwashed digestion residue (‘plastics fraction’ with a dry residue of 42 %) is about 12 MJ per kg fresh matter. In arncombined scenario (AD of the biodegradable fraction plus use of the digestate as refuse derived fuel) the net energyrnyield corrected for transport expenditures is 4.4 MJ/kg. This compares favorably to a net energy yield of 2.7 MJ/kgrnobtained from the conventional incineration of the bulk waste.