title: Two-fraction anaerobic fermentation of grass waste.
abstract: BACKGROUND
  Waste from public green areas represents large quantities of grassy phytomass. The grass is usually utilised by composting, combustion or anaerobic fermentation. However, the classical composts are time-demanding, the quality of accelerated composts is low, combustion is under increasing criticism and conventional anaerobic fermentation requires high investment.
  
  
  RESULTS
  A new method of two-fraction anaerobic fermentation of grass waste consisting from a hot maceration, up-flow anaerobic sludge blanket reactor, steam explosion, horizontally stirred batch anaerobic fermentors and a charcoal kiln, all run on waste heat from a co-generation unit was investigated on a commercial scale.
  
  
  CONCLUSIONS
  The results shows that due to faster energy utilisation the two-fraction technology requires smaller fermentors and hence the technology is approximately one-third less costly than conventional systems, with 4 years shorter payback time. Additionally, huge amounts of charcoal are produced. However, the process control and optimisation is more demanding.
authors: Department of Applied Plant Biotechnology, Agriculture Faculty, University of South Bohemia, České Budějovice, Czech Republic. josef.marousek@gmail.com
authors: Josef
authors: J
authors: Maroušek
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D002606:Charcoal; D003365:Costs and Cost Analysis; D005285:Fermentation; D018515:Plant Leaves; D006109:Poaceae; D012037:Refuse Disposal / Q000379:methods*; D012987:Soil; D013672:Technology; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D012987:Soil; D002606:Charcoal