12-Tungstophosphoric Acid Anchored to Zeolite Hβ: Synthesis, Characterization, and Biodiesel Production by Esterification of Oleic Acid with Methanol

Abstract

Heterogeneous acid catalysts comprised of 12-tungstophosphoric acid (10-40 %) and zeolite Hβ were synthesized, and 30 % loaded catalyst was characterized by various physicochemical techniques. The use of synthesized catalyst was explored for biodiesel production by esterification of free fatty acid, oleic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, and temperature were studied to optimize the conditions for maximum conversion. The catalyst showed high activity in terms of high conversion (84%) and a high turnover number, 1048. The kinetic study as well as Koros−Nowak test were carried out, and it was found that esterification of oleic acid follows first order kinetics with the calculated activation energy E a = 45.2 kJ mol −1 and pre-exponential factor A = 5.4 × 10 4 min −1 . The catalyst showed potential of being used as a recyclable catalytic material after simple regeneration without significant loss in conversion. As an application, preliminary studies were carried out for biodiesel production from waste cooking oil and jatropha oil, as feedstock over present catalyst.

Preparation of a Composite of Sulfated Zirconia/Metal Organic Framework and its Application in Esterification Reaction

“…As shown in Figure 7, the yield of methyl oleate (MO) increased with an increasing reaction time at 100 o C under MW irradiation, and after a 30 min reaction, the yield was around 87%. So far, the MO yields over conventional solid acid catalysts have been 67-95%, [49][50][51][52] suggesting the competitiveness of the SZ/MIL-101 catalyst in the ES for MO. Interestingly, the MO yield over pure SZ was negligible, confirming the necessity of dispersion or supporting of SZ for catalysis similar to reported results.…”

A comparative study on the catalytic performance of different types of zeolites for biodiesel production

“…All H-type zeolites were prepared from Na-type zeolites by following the ion exchange procedure reported by Patel et al [20]. The Na-type zeolite was added to a 2 M NH 4 Cl solution at the mass ratio of 1.0:1.0, and the mixture was stirred at 80.0°C for 2.0 h. Then, the samples were washed twice with the ultrapure water (resistance 18.2 MX, deionized and distilled from the Ulupure UPT-2-401 pure water system), subsequently filtered and dried at 100.0°C for 12.0 h, and finally calcined at 550.0°C for 6.0 h. The prepared zeolites were denoted by their Si/Al ratio in the parenthesis after each zeolite name.…”

Synthesis, Characterization and Applications in Catalysis of Polyoxometalate/Zeolite Composites

“…More recently, Narkhede and Patel studied this reaction over HPW 12 and HSiW 12 supported on Hβ zeolite [58]. The catalysts were those reported previously [47,48] and led to higher yields in smaller times (for example a 98% yield in 15 min instead of a 97% yield in 360 min). The reaction was then extended to other substrates (Table 3).…”

“…Patel et al studied the esterification of oleic acid with methanol catalyzed by HPW 12 supported on Hβ zeolite [47]. Heterogeneous acid catalysts comprised of 12-tungstophosphoric acid (10%-40%) and zeolite Hβ were synthesized by classical impregnation from an aqueous solution of HPW 12 and subsequent drying at 100˝C.…”