(757e) Application of Black Soldier Fly Larvae to Convert Municipal Organic Waste to Surfactants and Other Value-Added Chemicals

Current waste management practices are struggling to cope with economic growth and an ever-increasing global population. The UN estimates indicate that 1.3 billion tonnes of food waste are generated globally per annum. Municipal organic waste particularly represents a challenge in urban environments. Currently, the most relevant large-scale approach to recycling of this waste is the time-consuming process of compositing. Simultaneously, declining reserves of fossil resources and environmental concerns around the use of coconut and palm kernel oil present a need to identify new sources of the raw materials required for the production of fuels and chemicals. In this work, an approach to tackle both of these grand challenges is proposed using black solider fly larvae (BSFL). BSFL are highly effective in their consumption of waste, and the biological transformation of this into higher value organic oils with a variety of chemical applications. Therefore, BSFL have the potential to be a safe sustainable means of synthesising functionalised chemical feedstocks from municipal waste and can play a key role in the development of future biorefeneries.

In the present work, waste biomass is converted into proteins and lipids, the latter representing roughly 30% of the total larval body mass. Lipids extracted using soxhlet extraction with hexane, have been converted into chemical products such as bio-fuels, solvents, and surfactants. This process takes advantage of the capability of BSFL to consume municipal waste streams to accumulate body fat, behaving as living “bio-catalysts”, thereby avoiding many of the health and environmental issues associated with conventional methods of processing municipal waste. GC-MS analysis shows this to have a very similar composition to coconut and palm oils, i.e. free long chain carboxylic acids and in particular palmitic acid and lauric acid. Thus, BSFL can provide a renewable source of fats, and can be grown anywhere within the world, including developed countries where there are no local sources of free fatty acids. In countries where weather is unsuitable for their growth BSFL can be artificially reared.

This innovation provides a novel and sustainable route to consumer products via an alternative oil source. It can also exert a significant environmental benefit as food waste is a vastly overlooked driver of climate change, with the FAO UN 2011 assessment estimating the total carbon footprint of food wastage, including land use change, at around 4.4 Gt CO₂ per year. Our technology therefore provides a sustainable resolution in a sector responsible for 8.2% of total global greenhouse gas emissions (International Energy Agency 2014).