2. The problem of VOCs and siloxanes in biogas

Although biogas with a methane content of over 45% is flammable, it must be purified with a view to energy recovery, as the tolerance values in paragraph 1 indicate. In fact, some of the minority compounds making up biogas are harmful to the equipment or incompatible with the intended use.

Among these, hydrogen sulfide, water, nitrogen and ammonia have been the subject of numerous studies, and a wide range of technologies is available...