Upgrading biogas into syngas through dry reforming

Biogas is comprised of two major compounds (i.e., CH₄ and CO₂) derived from fermentation of organic wastes. Therefore, biogas can be used as a source for the generation of syngas (H₂ and CO: through dry reforming of methane). Given that the dominant fraction of biogas is consumed as a feedstock for lower-end products, such as heat and power, dry reforming can be used as an effective option for the valorization of biogas. In this review, we offer up-to-date knowledge on the development of biogas dry reforming in the context of the effects of the composition of the biogas, reaction conditions, and impurities in the biogas. Theoretical estimations of biogas compositions were made along with the compositional matrix of organic substrates. The thermodynamic calculations of dry reforming were also described with other side reactions. In conclusion, the challenges and the potential future directions of this research field were given to help open up new paths toward hybrid biological/chemical processes for H₂ production.