Esterification of oleic acid to biodiesel using biowaste‐based solid acid catalyst under microwave irradiation

Abstract

A novel carbon‐based solid catalyst was synthesized from waste biomass of watermelon peel (Citrullus lanatus) by one pot carbonization and functionalization with H2SO4 for biodiesel production. Oleic acid was utilized as a test substrate in this study given that it is a key component for majority of feedstocks used for biodiesel production. Synthesized catalyst was extensively characterized by X‐ray diffraction, Fourier transform infrared, thermogravimetric analysis, X‐ray photoelectron spectroscopy, scanning electron microscopy–EDX and Brunauer–Emmett Teller analysis. The catalyst revealed aromatic structure, hydrophilic OH and COOH groups as well as a high density of SO3H active centres with a total acidity of 3.6 mmol g−1. Using the optimized reaction condition (MeOH: oleic acid molar ratio 20:1, catalyst loading 8 wt.%, temperature 100°C and reaction time of 60 min) under microwave irradiation (50 W, 100 psi) a conversion as high as 94.36 ± 0.3% of oleic acid to biodiesel was reported. Activation energy of the esterification was found to be 38.16 kJ mol−1. Catalyst recovery was probed to over five reaction cycles, with a modest loss in activity (81.73 ± 0.4% conversion in the fifth cycle) resulting from limited active site leaching.

Transesterification of Jatropha curcas oil to biodiesel using highly porous sulfonated biochar catalyst: Optimization and characterization dataset

“…According to Barrett, Joyner, and Halenda's (BJH) analysis of the pore size distribution, the range was 4.12 nm. The high catalytic surface area and pore volume, at 1196.13 m 2 g −1 and 0.7711 cc g −1 , respectively, both were within the anticipated ranges [3] .

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“…At 1106 cm −1 , a peak was observed, subsequent to the symmetric stretching of SO 3 − . Formation of peaks can be seen at 1365 cm −1 and 1591 cm −1 , indicating the presence of carbonyl stretching (C=O) and C=C stretching in aromatic rings, respectively [3 , 4] . The stretching and bending vibration of C-H bonds were visible at 2482 cm −1 and 830 cm −1 .…”

In situ impregnation of cobalt‐doped tungstophosphoric acid on MOF‐801 toward enhanced catalytic activity for esterification

“…Additionally, based on the studies published in the literature, 57 the excess methanol was used in the process and made the esterification forward, and thus, the esterification process follows a pseudo‐first‐order model. According to the results shown in Figure 8a, it was evident that a clear linear relation was obtained between −In(1‐ X ) and t , and the R 2 value of each plot was determined to be 0.9989, 0.9840, and 0.9834 at 80, 90, and 100°C, respectively, proving that the esterification reaction in this work had pursued kinetics of first order 58 . More importantly, the k constant value increased up to twofold by raising the reaction temperature to 100°C.…”

Process Optimization of Biodiesel Production Using Waste Snail Shell as a Highly Active Nanocatalyst

“…As we keep the time constant and increase the temperature from 30 to 70 °C, the biodiesel yield also increases. The biodiesel yield is maximum when the temperature reaches 70 °C, and further increase in temperature leads to the evaporation of methanol leading to decrease in biodiesel yield [82]. The interaction between temperature and MTOR is depicted in Figure 12(e).…”