Introduction to heterogeneous hydrogenation and its application in the fine chemicals industry / Jacinto Sá -- Hydrogenation by nickel catalysts / Anna Śrębowata and Jacinto Sá -- Hydrogenation by copper catalysts / Damian Giziński and Jacinto Sá -- Hydrogenation by iron catalysts / Tomiła Łojewska and Jacinto Sá -- Hydrogenation by silver catalysts / Christina Paun and Jacinto Sá