I read Cradle to Cradle by William McDonough and Michael Braungart back in 2007 for my Sustainable Development class while I was working on my Masters at Clemson University. The book takes an interesting approach to how we view wastes and how we can transform them into valuable and marketable products, minimizing pollution and our impact on the environment. Their “cradle to cradle” or “closed loop design”, calls for utilizing waste streams as potential inputs elsewhere in a system, to save money on raw materials and lessen the inputs to landfills and waterways.
As I progressed in my Masters and learned more about industrial ecology and life cycle assessment, it became clear that there are many opportunities within a system to “close the loop” and design sustainable systems. Now that I have graduated, part of my work at Clemson University is to assess a system and find ways to generate co-products from wastes and design “cradle to cradle” systems, particularly within the fields of agriculture and biofuels/bioenergy.
The collaboration between the Organic Farm and the Sustainable Biofuels Initiative at Clemson have culminated in a business proposal called Brewcovery, which aims to take food and brewery wastes and transform them into valuable and marketable products, via the use of Hermetia illucens, or the black soldier fly. The basic design process will take waste streams, including preconsumer food wastes and brewery wastes and “feed” a population of black soldier fly larvae in a specially designed digester. The larvae, which eat up to 5x their mass daily, convert the wastes into castings, which is suitable for garden or small scale agricultural compost. The larvae are harvested from the digestor and placed into a dehydrator to dry. The dried larvae are then pressed in an oilseed press expelling two streams, an oil stream and a meal stream. The meal creates a suitable agricultural feed for chickens or fish, as it is high in protein and calcium. The oil stream will be converted into biodiesel and used to power the truck fleet. Once operational, this integrated system has high potential to create many niche products marketable to small scale agricultural producers, utilizing an existing and growing waste stream.
With several craft breweries already in the Carolinas, and plans for more breweries to expand here, the market is ripe for a business that will utilize the waste streams from these sources. Black soldier fly larvae consume yeast slurries and spent grains as well as pre and post consumer food wastes, all of which will be in high supply, especially given the recent revival of local and small scale agriculture producers.