The ISB Biodigester - What is it and What Happened? Matt Koe
With climate change rising at alarming rates, many businesses in the world - ISB included - are finding methods to reduce pollution and waste, in an attempt to make the Earth a better place. ISB itself has made multiple efforts to make the school more environmentally friendly, including reducing plastic use, solar panels and environmental service programs. Food waste is a major problem globally. To tackle their part in the problem, ISB built a biodigester.
Initially proposed in 2012, the biodigester was a machine built to transform food waste into energy. A biodigester “is a system that biologically digests organic material” (Minie Mallikarachchi). Bacteria in the biodigester breaks food down, turning it into fuel. Like composters, the biodigester is fully closed, eliminating odor and possible infestations, making it a clean product. According to the proposal notes, the biodigester was built to tackle food waste in the cafeteria, creating fertilizer for plants and used as an educational tool for students. The daily food waste from ISB cafeterias are estimated to be 100-150 kilograms, which the biodigester could bring down. After it was built, the biodigester cost $7000.
Kerry Dyke, who was responsible for setting up the biodigester, was excited about the impact it could’ve had. He said “It actually worked great, digested cafeteria waste and had no bad smell”, while producing high-quality fertilizer and gas strong enough to cook eggs. The PH level of the biodigester was always maintained at 7, and could eat up to 30-40 kilograms of waste a day. However, the flames were weak, taking 30 minutes to boil a pot of water, and the burn duration was inconsistent, sometimes lasting 40 minutes and sometimes lasting 20 seconds.
The biodigester worked just fine at the time, but due to problems with location, it got shut down in 2016. Due to scares of bad smells coming from it as well as the risk of explosion, the biodigester had to be installed far away from the cafeteria. This caused it to see minimal usage, as well as being hard to feed. “because its location was too far from the cafeteria we did not find a real practical use for the gas”, Mr. Dyke said. Although unfortunate, the story of the biodigester signals that ISB is making strides to improve its environmentalism. ISB is continuing to push for a greener campus - and everyone is here for it.