Preparation, characterization and thermal stability improvement of mesoporous sulfated zirconia for converting deodorizer distillate to methyl esters

This article reported a new procedure for synthesizing ordered mesoporous sulfated zirconia (m-SZ), an effective oxophosphate process for strengthening thermal stability of the as-synthesized m-SZ catalyst forming mesoporous phosphated sulfated zirconia (m-PSZ). The study also afforded a new reaction routine for synthesizing the m-SZ through condensation method using Zr(SO4)2 solution precursor in the incipient wetness impregnation method. The m-PSZ contained dense surface superacid sites being suitable for methanolysis of almost vegetable oils or animal fats producing methyl ester. The temperature of the condensation process was varied in the range of 70–100 °C, and the time periods were surveyed from 12 to 72 h for well self-assembling the mesoporous structure. The precipitation obtained from the condensations was calcined at 450 °C for 3 h after completely removing of the surface water overnight at 100 °C. The after calcination powder was the m-SZ catalyst. The H3PO4 was used as precursor for oxophosphate process producing the m-PSZ catalyst. The m-PSZ catalyst was applied to the methyl ester synthesis using deodorizer distillate collected from vegetable oil refinery in Vietnam as feedstock. The methanolysis was established at 130 °C for 4 h to obtain the refined methyl esters after passing through a purification process. The refined biodiesel characteristics were determined for its using in diesel engine, and the results showed almost positive values. Some techniques were used in the research such as XRD, TEM, BET, TG–DTA, NH3–TPD and GC–MS.