Abstract
Tokyo Gas has developed a compact and high-efficiency cogeneration system which can run with the mixture of biogas and natural gas, based on a new concept. To utilize the biogas whose amount of production varies from time to time, we have developed a gas mixture system that utilizes as much biogas as possible under simple and reliable control. Also, we have developed an air dilution system of natural gas to maintain stable combustion at the engine. Due to this system, the mixture ratio of biogas and natural gas can be anything from 0 to 100%. This gas mixture system and cogeneration plant has been installed at a beer brewery near Tokyo, and operating without any major troubles.