Co-digestion of energy crops and the source-sorted organic fraction of municipal solid waste.
The biological and technical performance during co-digestion of energy crops and the source-sorted organic fraction of municipal solid waste has been investigated at laboratory and pilot scale. A 50:50 (TS-based) mixture of energy crops and organic waste reached a loading rate of 6.0 gVS L(-1)d(-1) with a methane yield of 0.33-0.38 LgVS(-1), while a 80:20 mixture showed elevated levels of volatile fatty acids at 5.5 gVS L(-1)d(-1) The better performance of the 50:50 mixture can partly be explained by a better nutritional composition. Mincing the ley crop reduced viscosity and reduced problems with fibre floating and scum-blanket formation. The electricity consumed for mincing and stirring at a full-scale plant corresponds to ca 3% of the energy produced. Calculations of the costs for full-scale plants indicate that the price of the upgraded biogas has to be at least 0.078 Euro/kWh in order to balance the costs.
Nordberg
A
A
JTI - Swedish Institute of Agricultural and Environmental Engineering, P.O. Box 7033, SE-750 07 Uppsala, Sweden. ake.nordberg@jti.slu.se
Edström
M
M
D000383:Agriculture; D001421:Bacteria, Anaerobic / Q000378:metabolism; D001674:Bioelectric Energy Sources; D019149:Bioreactors / Q000382:microbiology; D003362:Cost-Benefit Analysis; D018556:Crops, Agricultural; D005735:Garbage; D008372:Manure; D029902:Medicago; D008697:Methane / Q000378:metabolism*; D006109:Poaceae; D012037:Refuse Disposal / Q000191:economics / Q000379:methods*
D008372:Manure; D008697:Methane