Biodiesel production from rubber seed oil using calcium oxide derived from eggshell as catalyst – optimization and modeling studies

Abstract

In the present study, Calcium oxide (CaO) obtained from eggshells has been used as a heterogeneous catalyst for biodiesel production from highly viscous non-edible rubber seed oil (RSO). Characterization of synthesized catalyst was done with the help of scanning electron microscope equipped with Energy dispersive spectrometry (SEM-EDS), X-ray diffraction (XRD) and Fourier transform Infrared spectroscopy (FTIR). Response surface methodology (RSM) with central composite design (CCD) was used to optimize the process parameters and 1H-NMR (Nuclear Magnetic Resonance) spectroscopy analysis was performed to find the conversion of RSO to biodiesel. A conversion of 99.7% of RSO to biodiesel was obtained at 12:1 methanol to oil molar ratio, 4 (wt%) of catalyst, and 3 hour reaction time with a quadratic regression model of R2 of value 0.9566 was obtained. The composition of prepared biodiesel is estimated with the help of Gas Chromatogram-Mass Spectroscopy (GC-MS) analysis. Artificial Neural Network (ANN) with Levenberg-Marquardt algorithm was also trained to predict biodiesel conversion and the value of R2 obtained was 0.9976. It was observed that predicted conversion values from ANN were better when compared to prediction using RSM.

Statistical analysis of experimental factor optimization in acid esterification of rubber seed oil

“…A reasonable acid value within the limits of ASTM standard was also observed for the synthesized biodiesel of all the four catalysts used. All the above results including the physico‐chemical properties of raw RSO and synthesized biodiesel were explained in detail as reported in our previous studies (Bharadwaj et al., 2019a, 2019b, 2019c; Sai Bharadwaj et al., 2020).…”

“…including the physico-chemical properties of raw RSO and synthesized biodiesel were explained in detail as reported in our previous studies (Bharadwaj et al, 2019a(Bharadwaj et al, , 2019b(Bharadwaj et al, , 2019cSai Bharadwaj et al, 2020).…”

“…The esterified RSO prepared as per the conditions presented in this study was used in biodiesel production (as reported in our earlier studies) using different heterogeneous catalysts. A high conversion of 99.7%, 95.95%, 95.20%, and 98.9% was observed while working with calcined eggshells (Bharadwaj et al., 2019a), fluorite (Bharadwaj et al., 2019b), calcined limestone (Bharadwaj et al., 2019c), and impregnated catalyst (Al 2 O 3 /calcined eggshells) (Sai Bharadwaj et al., 2020), respectively, as catalysts. The conversion percentage of esterified RSO to biodiesel was determined using 1 H nuclear magnetic resonance analysis.…”

A green approach for enhancing the hydrophobicity of UiO-66(Zr) catalysts for biodiesel production at 298 K

“…Recently, heterogeneous catalysts have been introduced to solve the aforementioned problems because of their many advantages, including easy separation from the reaction mixture, environmental friendliness and good reusability. 13,14 Various types of heterogeneous catalysts, such as ion-exchange resins, 15 alkoxides, 16,17 Mg-Al hydrotalcites, [18][19][20] metal oxides and hydroxides, [21][22][23][24] are used in biodiesel production by the alcoholysis of vegetable oils, animal fats or various fatty acids. Heterogeneous base catalysts are more efficient in activating the reaction than acid catalysts.…”

Biorefinery of Rubber Seed Kernels for Comprehensive Utilisation

“…Several studies have investigated the use of rubber seed oil to produce biofuels (Reshad et al, 2015;Sai Bharadwaj et al, 2019; Samart et al, 2019). Rubber seed oil applications in production of cosmetics (Chaikul et al, 2017;Lourith et al, 2014), alkyd resin (Ikhuoria et al, 2007) and polyurethane resin (Bakare et al, 2010) also merit attention.…”