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Electrolysis consists in the dissociation of H₂O and/or CO₂ by means of electricity. One of the main advantages of the co‐electrolysis is the production of H₂ and CO simultaneously (synthesis gas or syngas). Syngas is widely used to produce a wide range of chemicals [112, 113]. The Fischer–Tropsch process is one of the main processes where syngas is involved. The Fischer–Tropsch process consists of the H₂ and CO transformation into hydrocarbons of longer chains than methane. Hydrocarbons are the basis for the production of gasoline, diesel, and chemicals such as olefins and waxes. The type of catalyst selected (usually Fe and Co), design of the reactor, and the process conditions will shape the product selectivity in the Fischer–Tropsch process. Usually, Fischer–Tropsch synthesis takes place at temperatures between 200 and 300 °C and pressures comprised between 1 and 6 MPa. Among all the reactions that occur during Fischer–Tropsch synthesis, the main desired reactions can be addressed with the production of alkanes or paraffins (see Eq. (3.12)), alkenes or olefins (Eq. (3.13)), and alcohols (Eq. (1.14)) [114].

(3.12)

(3.13)

(3.14)

Apart from the reactions described above, some undesired reactions might also occur in the process as WGSR, carbonaceous materials, Boudouard reaction, and bulk carbide formation.

The synthesis of methanol and methane can also be derived from the syngas [115]. Methanation and methanol can be performed directly from the syngas or by CO₂ hydrogenation. The main reactions for both syntheses are described below. For both processes, WGSR plays an important role and affects the selectivity to the final products.