Glycerol conversion in the experimental study of catalytic hydrolysis of triglycerides for fatty acids production using Ni or Pd on Al2O3 or SiO2

In many reactions to produce biodiesel the glycerol represents 10 wt% of the total products therefore it is important to find an adequate destination of such byproduct. The catalytic hydrolysis of triglycerides is another way to produce biodiesel from fatty raw materials. This work shows the catalytic hydrolysis of triglycerides (soybean oil and tallow) with nickel (NiO) or palladium (PdO) catalysts supported on Al₂O₃ or SiO₂. The results showed the direct conversion of in situ generated glycerol into hydrogen (H₂) and carbon dioxide (CO₂). The glycerol conversion was evaluated through the capacity to hydrogenate the unsaturated fatty acids leading to the formation of stearic acid (saturated compound). The catalyst, temperature and time were varied and evaluated in the experiments utilizing the two different kinds of raw materials (beef tallow and soybean oil). Selectivity and statistical planning studies were performed to optimize the formation of stearic acid as it is linked to the hydrogenation of unsaturated compounds by hydrogen generated from the glycerol liquid reforming.