11. There are three companies operating four biogas digesters with a fifth under construction. 12. Other treatment methods include heat, alkaline digesters and the use of microwaves. 13. Over the years, there have been a number of people promoting methane digesters . 14. The digester is an airtight circular pit made of concrete with a pipe connection. 15. Therefore, many digesters operate with codigestion of two or more types of feedstock. 16. Digesters processing dedicated energy crops can achieve high levels of degradation and biogas production.17. In 1859 a leper colony in Bombay in India built the first anaerobic digester . 18. One use of vinasse is in thermophilic digesters . 19. These Aerobic Digesters are supplied with air from 3 blowers in a Blower House. 20. The digester typically produces biogas with a high concentration methane ( c80 % ).
