Abstract
Anaerobic high-solids single-stage stratified bed digesters have been found to be simple and flexible design candidates for small-scale reactors located in medium- to low-technology environments. In the present study, wheat straw was used as the starter material for the stratified bed. Upon green mass feeding, the anaerobically stabilised straw bed functioned both as a biofilm support and as a particulate filter. It enabled a direct onset of 7 kg VS m(-3) batch loads, added twice a week, and permitted a low but consistent bed permeability during feeding at an average superficial flow velocity of 1 m d(-1) to be achieved. Fed-batch tests with sugar beet tops in pilot- and laboratory-scale setups at an average loading rate of 2 kg VS m(-3) d(-1) resulted in average biogas production rates of 1.2-1.4 m(3) m(-3) d(-1) and methane yields of 0.31-0.36 m(3) kg(-1) VSadded. At the end of the laboratory-scale feeding trial, the 200 day old straw bed had compacted to 50% of its initial volume, without any negative effects on performance being detectable. (c) 2005 Elsevier Ltd. All rights reserved.
Original language | English |
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Pages (from-to) | 46-52 |
Journal | Bioresource Technology |
Volume | 98 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2007 |
Subject classification (UKÄ)
- Industrial Biotechnology
Free keywords
- lignocellulosics
- fixed bed
- farm-scale
- dry digestion
- packing density
- crop residues
- straw bed priming
- foaming
- intermittent leachate recycle