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 processes and 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?)