Low energy density in agricultural or biotechnological raw materials dictates the need for their local processing. Small-scale agricultural products or waste processing plants can`t profitably use technologies common in large-scale petrochemistry, including the complex and expensive process of steam reforming of biogas into syngas for its subsequent conversion to liquid fuel. The work suggests using small-scale sources of inexpensive and easily obtained biogas and other renewable hydrocarbon gases for the production of liquid biofuel by their air conversion in recently developed matrix reformers into low-cost nitrogen-rich syngas, followed by Fischer-Tropsch synthesis in a cascade of sequential reactors. Autothermal matrix reformers are very compact, simple in design, have several times more specific volume capacity than traditional technologies, and allow processing biogas with a high concentration of CO2. The advantages of low-cost conversion of biogas to liquid fuel based on nitrogen- enriched syngas with subsequent Fischer-Tropsch synthesis are discussed.