Performance comparison of Ni-Fe loaded on NH₂-functionalized mesoporous silica and beach sand in the hydrotreatment of waste palm cooking oil

Preparing the commonly-used mesoporous silica (MS) catalyst support from a natural source involves a step-by-step extraction process which requires the use of chemical reagents that are harmful for the environment. Based on this consideration, a direct use of natural ingredient for catalysis support without prior extraction is very interesting to look into. In the present work, the catalytic performance of Ni supported on amine-functionalized beach sand (Ni-NH2-Sand) was thoroughly compared with the activity of three MS-supported catalysts (i.e. Ni-NH2-MS, Fe-NH2-MS, Ni-Fe-NH2-MS) in the hydrotreatment of waste palm cooking oil at 450 °C. All catalysis materials were synthesized from Parangtritis Beach Sand comprising Fe2O3 (31.75 wt%), SiO2 (43.09 wt%), and Al2O3 (12.91 wt%). This study found that among all MS-supported catalysts, monometallic Ni-NH2-MS comprising 2.29 wt% of Ni generated the highest liquid hydrocarbon yield with over 64.44 wt% conversion. Achieving such a comparable result was possible for sand-supported catalyst by adding 10 times more Ni loading than Ni-NH2-MS. This was shown by the 66.83 wt% liquid hydrocarbon that was successfully collected from the hydrotreatment of waste palm cooking oil in the presence of Ni-NH2-Sand catalyst containing 20.75 wt% Ni, 27.28 % Fe2O3, and 16.76 wt% SiO2. The result describes a potential use of sand as an alternative catalyst to produce green fuel.