Catalytic conversion of biogas in a biorefinery context: prospectives and challenges

The current energy scenario is changing and challenging, with a current trend focused on the search for alternative energy sources to reduce energy dependence due to different factors such as geopolitical aspects, among others. In this sense, apart from the obvious environmental advantages compared to refineries based on oil, biorefineries based on different wastes (with a difficult management approach) could be an interesting starting point to foster sustainable economic growth of different areas around the world. For instance, biogas is a promising energy source with endless opportunities, depending on its final use. In this sense, a gas with a relatively homogeneous gas composition can be obtained from variable wastes (agro-industrial, wastewater, manure, etc.), with a wide range of technologies related to energy production (upgrading, steam reforming, Fischer--Tropsch synthesis, etc.). However, high efficiency for these biorefineries is required in order to compete with traditional refineries. In this context, the role of catalysts is essential, which can have an influence on biorefinery processes (and, equally, these processes can influence their catalytic performance). Considering the above, the aim of this work was to assess, according to our own experience and resorting to the literature, different aspects related to catalytic conversion of biogas through different technologies (mainly steam reforming and Fischer--Tropsch synthesis). As a result, several recommendations like the use of high-quality biogas and purification technologies are offered in order to improve the efficiency of these processes.