UASB treatment of liquid residues from grass bioraffination.
In 2001 the first green biorefinery started operation in Switzerland with a design load of 5,000 tons dm of grass per year and a combined output of fibres (0.4 tons per ton input), protein (160 t/t) and bioenergy (500 kWh/t). Bioenergy was produced in a 570 m3 UASB reactor which has been monitored intensively during its first year of operation. Anaerobic treatment of liquid residues with > 80% degradation of organics was shown up to high f/m ratios and loading rates of 12 -15 kg COD/m3 d and specific biogas production of 0.5-0.65 Nm3 of gas per kg of COD added. A mass flow analysis of solids and pellets leads to the conclusion, that due to a low sludge bed volume of only 16% of the reactor combined with a low actual organic loading of 1.5 kg COD/m3 d there was a restricted adsorption and a low degradation of substrate solids.
Baier
U
U
Department of Biotechnology, University of Applied Sciences, Gruental, CH-8820 Waedenswil, Switzerland.
Delavy
P
P
D001421:Bacteria, Anaerobic / Q000378:metabolism; D001674:Bioelectric Energy Sources; D019149:Bioreactors; D008697:Methane / Q000378:metabolism*; D006109:Poaceae; D012722:Sewage; D013557:Switzerland; D014865:Waste Disposal, Fluid / Q000379:methods
D012722:Sewage; D008697:Methane