Primary processing

A checked version of this page, approved on 27 August 2021, was based on this revision.

Primary processing of biowaste results in intermediate chemicals and/or materials which will then go into the secondary processing after which the final product is obtained. While some technologies are used exclusively for the purpose of primary processing, others (such as the separation technologies) can be utilised in both primary and secondary processing.

Biochemical processes and technologies

Aeration
Anaerobic digestion
Enzymatic conversion (in vitro)
Composting
Insect farming

Chemical processes and technologies

Hybrid processes and technologies

Pulping
- Chemical pulping
  - Organosolv
  - Soda
  - Sulphate
  - Sulphite
- Hybrid pulping
  - Neutral Sulfite Semi Chemical pulping (NSSC)
  - Chemithermomechanical pulping (CTMP)
- Mechanical pulping
  - Refiner
    - Thermomechanical pulping (TMP)
    - Refiner mechanical pulping (RMP)
  - Groundwood
    - Stone groundwood (SGW)
    - Thermal groundwood (TGW)
    - Pressure groundwood (PGW)

Physical processes and technologies

Densification
- Pressure densification
Microwave
Pressure-densification
Sizing
- Chipping
- Grinding
Steam explosion
- Air
- Supercritical CO₂
Thermal expansion
Ultrasonication

Separation pre-treatments

Physicomechanical separations
- Centrifugation
- Filtration
  - Membrane Filtration
  - Pressure filtration
  - Ultrafiltration
- Sieving
Physicochemical separations
- Chromatography
- Dialysis
- Dissolution, Crystallisation, flocculation, precipitation
- Distillation
- Drying
- Extraction
  - Acid treatment
  - Alkali treatment
- Extrusion
- Field-Flow fractionation (FFF)
- Integrated hydroxyl radicals and hot water pre-treatment (IHRWT)

Thermochemical processes and technologies

Ammonia fibre expansion
Gasification
Hydrothermal
Pyrolysis
Torrefaction
- Dry torrefaction
- Wet torrefaction