Biofuels and Bioenergy

Statement of the Problem & Aim: According to the OPEC World Oil Outlook in 2040 the increase of diesel and jet fuel worldwide demand about 20% and 40%, respectively in comparison with today is expected. The increasing worldwide consumption of fossil fuels evokes efforts and usage of renewable raw materials for the production of biofuels which decreases the accumulation of greenhouse gases and allows restricted consumption of non-renewable crude oil reserves. The hydrotreating of triglycerides now-a-days seems to be a perspective way for the production of renewable component into diesel fuel. The purpose of this study is to compare the activities of sulfidic Ni Mo/γ-Al2O3 and Co-Mo/γ-Al2O3 and reduced Ni/γ-Al2O3 catalysts for the hydrotreating of rapeseed oil Methodology & Theoretical Orientation: Continuous flow reactor with an inner diameter of 21 mm and fixed bed ofcatalyst was used. The reaction temperatures in the range of 260 360°C, the pressure of 4 MPa and WHSV of 2 h-1 were tested Findings: The complete deoxygenation of triglycerides was achieved at temperatures of 320ºC; 340ºC and 360°C with Ni Mo; Ni and Co-Mo catalysts, respectively. The intensive hydrogenolysis of alkanes and methanization of CO and CO2 at higher reaction temperatures were observed on Ni catalyst. Gaseous products from Ni catalyst thus containe only a minor amount of CO, CO2 and propane in contrast to both types of sulfidic catalysts. Hydrodeoxygenation (HDO) reactions were almost in balance with hydrodecarbonylation (HDCn) and hydrodecarboxylation (HDCx) reactions in case of both sulfidic catalysts. Higher isomerization activity of Co-Mo catalyst was observed incomparison with other tested catalysts Conclusion & Significance: Reduced Ni/γ-Al2O3 catalyst is a perspective type of catalyst for hydrotreating of neat triglycerides. The activity of this type of catalyst is sufficient and additionally, the doping of the feedstock by sulphur compound for the preservation of catalytic activity like in case of sulfidic catalysts is not necessary.