Gasification unit. Historical illustration of a gasification unit (wood gas generator), also known as a gazogene. Gasification converts carbon-based materials, such as coal, biofuel and biomass, into a mixture of carbon monoxide and hydrogen (wood gas) for use as a fuel. This design, with an aspirator (centre) used to extract the gases produced, is by the company founded by German engineer Nikolaus Otto. Artwork from 'Moteurs' (1911) by French civil engineer Max de Nansouty (1854-1913), part of the 'Les merveilles de la science' series of 1867-1891 by Louis Figuier.