Engineering & construction


BES-CSTR process

DRANCO nv offers the design and construction of wet completely mixed digesters. These digesters work at a low total solids-content and can be used as main digesters, or as post-digesters (e.g. following a DRANCO-FARM or BES-Plugflow digester).



DRANCO nv uses this type of technology for clean and wet organic feedstocks such as energy crops, agro-industrial residues or food waste. The BES-CSTR is a continuously stirred tank-reactor with a gas storage on top.

BES-CSTR characteristics

  • round digester in concrete
  • total solids content between 2 and 12% in the digester
  • mesophilic or thermophilic operating temperature
  • easy replacable stirrers
  • modular concept
BES-CSTR Plant in Langendorf (Germany)
BES-CSTR Plant in Langendorf (Germany)


The BES-CSTR process has some significant advantages:

  • simple design
  • short construction period
  • optimal heat- and material distribution inside the digester
  • limited height
  • efficient degassing inside the digester
  • large digester volumes possible


Mr. Winfried Six
Marketing & Sales Manager



DRANCO nv is doing the biological and technological follow-up of several CSTR digesters (see our BCS-division).

See also our CSTR-reference in Nüstedt and Langendorf.