Biogas is a gas produced by the fermentation of organic matter in the absence of oxygen. Depending on its origin, its methane (CH4 ) content can vary from 30 to 65%. The analysis of biogas and the control of its quality is an essential step in the development of any methanization project. Its composition can change over time, so it is necessary to control its quality regularly.

As for syngas or synthesis gas, it is a combustible gas mixture produced by pyrolysis. Composed ofhydrogen (H2), carbon monoxide (CO) andgaseous hydrocarbons, it is a poor gas (half as energetic as natural gas), dirty, toxic, acidic and corrosive if it has not been carefully purified. Hence the importance of analyzing its composition.