Scaling Up Black Soldier Fly Food Scrap Processing | Phase Iby Terry Green on 11/16/12
Dipterra (www.dipterra.com)we have devoted
considerable effort over the last few years collecting data on the
characteristics of Black Soldier flies regarding how to propagate them year
round, and their role in accelerating the decomposition and recycling of
nutrients in food scrap waste. There is much interest in using Black Soldier flies
in recycling food scrap as an alternative and more sustainable method of
recycling biodegradable wastes relative conventional composting biotechnologies.
Just search the internet under “Black Soldier fly”, “Hermetia illucens”,
“Soldier grub” or “Phoenix worm” - you will find lots of information and examples of
different Black Soldier fly food scrap processing bins.
At Dipterra we believe there is also a significant economic opportunity in scaling up the use of Black Soldier fly processing of food scrap and agricultural wastes. We have committed to scaling up the propagation and application of larvae to gain more practical experience on the feasibility of making the process commercially viable. This seems a reasonable and worthy goal given the valuable byproducts (high quality larval feedstock, chitin derived from the exoskeleton, the recovery of leachate beneficial to plants as a foliar spray and soil conditioner, etc.) which could be realized in offsetting the cost of recycling food scrap and biodegradable agricultural waste.
What works efficiently on a small scale doesn’t however necessarily translate efficiently in scaling up. We believe it is nevertheless important to take the plunge in scaling up food scrap recycling using Black Soldier flies. In this regard, we at Dipterra are building a scaled up Black Soldier fly processing unit inside an enclosed 10x24 ft shed constructed at New Earth Farm. What follows are updates we intend to relay from time to time through our blog as work progresses, starting here with "Scaling Up Black Soldier Fly Food Scrap Processing – Phase I".
Our goal is to encourage scale up operations by demonstrating the use of Black Soldier flies in processing wastes on a larger scale aimed at creating an economical and viable Black Soldier fly processing industry. How great it would be to operate a business, create jobs, recycle locally and realize products of value from waste – all with the help of the humble Black Soldier fly!
We sited our DipTerra food scrap processing Black Soldier fly shed where we intend to propagate larvae and recycle food scrap year round. Figure 1 shows the layout of the foundation for our processing shed staked out at the very beginning of construction. We built our 10x24 ft shed on 39 pressure-treated 4x4 posts, each set in gravel and concrete laid down after drilling out post holes with an auger. We then secured 4x6 ft pressure treated beams on top of the posts on which the subfloor rests.
Fig. 1. Scott Olsen (left) of New Earth Farm, and Terry Green (right) of DipTerra work with automated auger used to dig foundation post holes in laying out the BSF processing shed foundation.
Because our site is located in a temperate zone, where winters preclude propagation of larvae year round outdoors, we have taken special care to insulate the underside of the floor, walls and ceilings, and to also design the roof with large double pane insulated windows for gathering as much sunlight while maximizing heat retention inside the processing shed during the winter months. We included large insulated double-pane windows on the East, South and West sides of the shed to also capture as much light as practical year round. Natural lighting is important since Black Soldier flies mate more efficiently under the latter conditions.
Once the posts and floor joists were anchored in place, high efficiency insulation board was added beneath the subfloor as it was installed on top of the beams (Figure 2). We framed the walls of our processing shed using 2x6 studs spaced approximately 2 ft apart on 2x6 ft plates nailed around the perimeter of the floor. The shed has just over a 2" pitch for the roof - 10 ft walls on its North side, and 8 ft walls on the South wall. Its long axis runs East and West allowing sunlight to stream into the shed throughout the day through skylights built into roof using recycled double pane windows.
Fig. 2. View of BSF shed with rough 2x6 framing of walls nailed into footer plate at the perimeter of the shed subfloor supported on floor joists - note insulation on the underside of the subfloor will help in managing the temperature inside the shed, especially as winter approaches.
Comments on this blog or any of our other blogs are always welcome. Want to find out the latest happenings? Subscribe to our blogs through our RSS feed – just click on the RSS icon at the top of any of our website pages and follow the instructions in registering how you want to receive the feeds. For additional information, you can also visit our Forums website page where general questions and answers regarding Black Soldier flies and recycling options can be found.
More to come in Phase II as a follow-up. Stay tuned.