Pyrolysis: Waste to fuels

Forestry slash

Pyrolysis involves heating substances in the absence of air. In the case of organic material (wood, tyres, plastics etc) this leads to simpler hydrocarbons as liquids, chars and gases. It avoids combustion (oxidation) that produces noxious emissions and significant quantities of NOx, SO2, CO2 etc.

It produces three types of product: chars that can be used as fuels; liquid fuels similar to petrol through to diesel (wood produces more complex liquids); and flammable gases. It is useful as a last resort for recycling wastes that are difficult to otherwise reuse such as tyres, or cannot be economically sorted and cleaned for higher value reuse for example as feedstocks in plastics manufacturing.

Like most thermo-chemical processes it gets cheaper the bigger it gets, but wastes are a low value distributed feedstock and running very large plants close to urban centres creates environmental concerns that are costly to manage. Fuels from these systems are expensive to upgrade to replace fossil fuels.

Instead Nufuels has been working on small scale decentralised opportunities making fuels that are fit-for-purpose for local use. Our primary focus is on the Pacific Islands, but we have identified two other niche markets where both disposal and fuels are valued sufficiently to make the businesses economic:

  • small scale (~1 tonne batch per day) for processing of tyres in Provincial New Zealand producing fuels for heat loads; and
  • small scale (<1 tonne batch per day) processing of complex plastics-based waste materials not suitable for reuse.

If you have difficult wastes and want to check out if we could help contact Leigh Ramsey.