UC Davis Biogas Energy Project

This video demonstrates an interesting biogas project by the University of California, Davis. The biogas plant, unlike many others, actually processes solid organic wastes without needing any prior treatment.

Main Biogas Page

• Learn about biodigester construction - See the biodigester design that the women's group used for its biogas project
• Video on how to make an anaerobic methane digester - Transcription of the English translation with link to the video
• Biogas and Biodigester FAQ's - Learn the basics about biogas and get some of your specific biogas questions answered
• Read our collection of online biogas articles - Learn about biogas in other parts of the world from a newly-updated compilation of online biogas articles
• Learn how to make your own homemade biodigester - This book offers an easy-to-use, step-by-step illustrated manual on how to make your own homemade biodigester to create biogas in your very own backyard.

Biogas Video Transcript

Welcome to the onsite power systems UC Davis Biogas Energy Project.An advanced technique that will take organic waste and create sources of renewable energy and biofuels that will help reduce our state's and country's dependence on foreign oil. The biogas energy project demonstrates an advanced anaerobic digestion technology capable of processing high solid and high liquid waste matter. The advantage of this system is that traditional digesters can only handle high-liquid waste, and this system can handle high-solids, including grass clippings and food waste without any sort of pre-processing. The waste goes through two stages in the anaerobic digestion process. The first stage breaks down the material and makes water and organic acid. The second stage takes those organic acids and makes methane gas. The two stages of the digestion process have different types of bacteria strains. The first step's bacteria is very hardy and can survive under almost any conditions, whereas the bacteria in the second stage that make the biogas are very sensitive to temperature and pH. This process separates those two stages, allowing each bacteria type to have an optimal environment. First we load the organic materials into a tank, allow it to break down at its own rate. As the material breaks down it produces water and organic acids. We take the water from the tank and decant it and feed it to a second tank where the bacteria that make the methane gas are housed. In that tank, or the gasification tank, we keep the optimal environment for the bacteria: 135 degrees Fahrenheit and a neutral pH level. At regular intervals we'll take water from the first stage tanks, along with the right amount of acids to feed it to the gasification tank. With this we get a very steady production of biogas. Typically food waste will break down in 5-7 days, green waste in 10-12 days, and we let the material stay there as it creates the water and the acid, and then we feed it to the gasification tank.