Complete the paragraph.
(55% to 60%, methanogenic, microbes, 65% to 70%, nitrogen, acetic, nitric, carbon
dioxide, anaerobic)
Production of biogas is an ...................... process. It takes place in two stages. The .........................act on
the biodegradable complex organic compounds and produce organic acids such as ........................ acid.
The ......................... bacteria act on the organic acids to produce methane gas which is also called
biogas. Biogas contains about ......................... methane and the rest is ...................... . It is a fuel which is
convenient to use and, in addition to this, a very good manure is also produced as a side product of the
process.