Ethylene production by steam cracking produces several by-products such as pyrolysis gasoline (pygas). Raw pygas contains highly valuable components such as BTX (benzene, toluene, xylenes), unsaturated compounds like diolefins, styrenics and olefins, and sulfur-containing compounds. In order to recover BTX, the unsaturated compounds and sulfur compounds have to be removed efficiently. This is the target of Axens’ catalysts through two different stages of pygas hydrogenation.