Systems and Processes


A batch system is one in which a quantity of material is introduced to the reactor, processed and then removed.

Advantages of batch processing:

  • Simplicity
  • Lower capital costs
  • Flexibility
  • No flow pattern problems
  • Accurate control over digestion times
  • Ease of processing high dry matter materials
  • Ease of isolating problems
  • Ease of maintenance
  • Less dependence on regularity of feedstock
  • Possible to start and stop the digester
  • Possible to gain access to the digester between batches

Constant Flow

A constant flow system is one in which material is constantly added to the reactor at one end, is processed as it passes through, and then ejected at the other end.

Advantages of constant flow:

  • Easily automated
  • Low operating costs
  • Low maintenance
  • High gas yields
  • Odour free sealed process
  • Small footprint
  • Regular spike free energy requirements