Secondary processing

Secondary processing covers either the direct or indirect (processing of intermediates from primary processing) valorisation of biowaste into a final product. While some technologies are used exclusively for the purpose of secondary processing, others (such as the separation technologies) can be utilised in both primary and secondary processing.

Biochemical

• Composting
• Anaerobic digestion
• Gas fermentation
• Industrial fermantation
• Insect farming
• Solid state fermentation

Biocomposite processing

• Co-processing with plastics via extruder (see: UBQ)

Physicochemical

• Chemical extraction
• Crystallisation, flocculation, precipitation

Thermochemical

• Gasification
  • Air/Oxygen gasification
  • Catalytic gasification (indirect hydrogenation)
  • Hydrogasification (direct hydrogenation)
  • Steam gasification
• Pyrolysis
  • Catalysic cracking
    • One-step process
    • Two-step process
  • Hydrocracking
  • Thermal cracking
  • Thermal depolymerisation (does this apply also to biowaste?)