In many countries, a considerable proportion of wasted food and food residues still ends up as mixed putrescible waste which contains a high-water content and which may vary considerably both regionally and seasonally. Market assessments show domination of crop-based commodity feedstocks such as maize or corn and plant-based lipids rather than food chain wastes. The authors investigate the conversion of mixed post-consumer organic putrescible food waste materials into fuels and chemicals.
This report investigates conversion of materials left uneaten at the consumer/retail stage which are discarded into a general waste or food waste disposal stream (mixed post-consumable organic putrescible food waste materials) into fuels and chemicals.
It focuses on three aspects: researching the conversion of mixed post-consumer organic putrescible food waste materials into chemicals and fuels; data sources that can be used to characterise mixed putrescible waste that fit with the existing context of composition of post-consumer putrescible food waste in the EU; and experiments to identify the key genetic features of bacteria suitable for growing on a mixture of putrescible waste and further steps required to explore candidate chemicals for prospects of production by way of an example with regard to bioplastic PHB production.
Key findings and next steps
- Characterising food waste composition indicates that valorising mixed post-consumer putrescible food waste for fuels and chemicals is challenging due to the variability of waste streams.
- Evidence for the potential conversion of consumer putrescible mixed food waste to a selection of candidate fuels and chemicals found in the literature is limited. Research is evident at the laboratory scale with some promising EU pilot scale approaches currently being implemented. Most scaled bio-based fuels and chemicals currently rely on crop-based commodities.
- In this deliverable state of the art microbial genetic technology has been successfully used to select, from a large diversity of many individual clones of a bacterial isolate, mutants that can grow successfully on a characterised putrescible waste.
- All successfully growing clones have been sequenced to identify which genes changed to allow improved growth.
- This is a successful step towards producing commercially viable strains for the valorisation of mixed post-consumer food wastes into bacterial biomass.
The next steps would be to use these findings to investigate the selected strains for possible candidate chemical production in pilot scale research applications such as biopolymer PHA.
Wain, J., Waldron, K., Moates, G., Metcalfe, P., 2019: Viability of bio-based chemicals from food waste. REFRESH Deliverable 6.8