Although the primary focus of this book is on carbons and carbon supported catalysts, it also identifies the difference in the effect of carbon supports compared with the oxidic supports, particularly that of y-AL2O3. Although many books claim to have the same objective, this publication is unique as the difference in catalyst activity and stability was estimated using both model compounds and real feeds under variable conditions. The conditions applied during the preparation of carbon supported catalysts are also comprehensively covered and include various methods of pretreatment of carbon supports to enhance catalyst performance. The model compounds results consistently show higher hydrodesulfurization and hydrodeoxygenation activities of carbon supported catalysts than that of the y-Al2O3 supported catalysts. Also, the deactivation of the former catalysts by coke deposition was much less evident. Importantly, in this book, most of the model compounds studies on hydrodesulfurization and hydrodeoxygenation were conducted in the absence of nitrogen compounds, as the poisoning effects of such compounds on hydroprocessing reactions are well known