Abstract:
The research focused on production of bio-hydrogenated diesel (BHD) as green diesel becoming more attractive for utilization as a renewable energy fuel source for diesel engines. BHD as 2nd generation biodiesel can be produced from hydrotreatment of vegetable oils. The present work investigated the hydrodeoxygenation (HDO) of palm oil catalyzed by unsupported Ni-Mo sulfide (Ni/Ni+Mo atomic ratio of 0.2) prepared by hydrothermal method. The effects of operating parameters, such as time, temperature and oil concentration, on the oil conversion and products distribution were evaluated. The long time and higher temperature promoted the reaction via decarboxylation and decarbonylation pathways. Under the appropriate conditions (temperature of 300 °C, time of 3 h, initial H2 pressure of 30 bar), the yield of C15 - C18 was 81.4 wt%, while the selectivity of n-C15, n-C16, n-C17 and n-C18 was 23.6, 18.0, 32.0 and 25.6%, respectively. From gas chromatography-mass spectrometry (GC/MS) analysis, the by-products such as n-alkenes, alcohols and esters, were found. From catalyst characterization, the catalyst had the sandwich structure consisting of weakly coupled layers, the rim sites and Ni edge which catalyzed the reaction efficiently. The catalyst can be reused for at least 4 cycles of palm oil HDO with retention of good performance.