Esterification of Jatropha Oil with Isopropanol via Ultrasonic Irradiation

Abstract

Abstract:The reduction of high acid value (AV) of inedible jatropha oil (JO) by esterification with isopropanol (IPA), which is a common alcohol solvent waste in Taiwan's high-tech industry, was studied. The decrease of AV is beneficial for the subsequent transesterification to produce JO biodiesel (i.e., biodiesel of fatty acid isopropyl ester (FAIE)). Acid catalyst (H 2 SO 4 ) and a novel mixing/emulsion technique using ultrasound irradiation (UI) were applied to promote and facilitate the esterification process. The results showed that increased IPA/oil molar ratio (M IOE ) can significantly reduce the AV, kinematic viscosity (KV), density (ρ LO ), and water content (M W ) of esterified JO, while also providing the benefit of enhancing the yield (Y F ) of biodiesel of FAIE. For example, with M IOE = 5 at esterification temperature (T E ) = 394.2 K (393.8-394.7 K), a reduction of AV of 99.25% with Y F of 67.15% can be achieved. Free fatty acid (FFA) was reduced from 18.06 wt.% to 0.14 wt.%, indicating 17.92 wt.% out of 18.06 wt.% of FFA was esterified to FAIE. As a result, among the Y F of 67.15%, 49.23% (= 67.15 wt.% deducting 17.92 wt.%) was contributed by the transesterification of triglycerides. By esterification of high FFA-containing raw JO with acid catalyst, one can not only avoid saponification, but also reduce the loading of the subsequent alkali-catalyzed transesterification. Moreover, increasing T E from 394.2 to 454.4 K further reduced AV (from 0.27 to 0.084 mg KOH/g) and M W (from 0.27 to 0.043 wt.%), but, on the other hand, it increased KV (from 14.62 to 25.2 mm 2 /s) and ρ LO (from 901.6 to 913.3 kg/m 3 ), while it decreased Y F (from 67.15 to 25.84%). In sum, IPA was successfully used as a replacement for methanol in the esterification of JO while UI provided mixing/emulsion along with heating resulting from cavitation for the system.

Subcritical Hydrothermal Co-Liquefaction of Process Rejects at a Wastepaper-Based Paper Mill with Waste Soybean Oil

“…into a crude bio-oil product and a gaseous product via hydrothermal processing [26]. The constituents of a crude bio-oil product include phenol and its alkylated derivatives [27], heterocyclic N-containing compounds [28], long-chain fatty acids, alkanes and alkenes, and derivatives of phytol and cholesterol [29,30]. Some compounds are the same as this study.…”

Use of Co/Fe-Mixed Oxides as Heterogeneous Catalysts in Obtaining Biodiesel

“…The transesterification technique is the most used because it is easy to carry out; however, the type of catalyst used is important to ensure that the reaction has direct effects on the efficiency of the process and the quality of the products. The catalysts used can be homogeneous, heterogeneous or enzymatic (Figure 1) [7][8][9]. Each of the catalytic processes used to obtain biodiesel presents advantages and disadvantages.…”

Intensification of Continuous Biodiesel Production from Waste Cooking Oils Using Shockwave Power Reactor: Process Evaluation and Optimization through Response Surface Methodology (RSM)

“…In the last decade, research on biodiesel production processes have concentrated on the development of process-intensification technologies to enhance the mixing and mass/heat transfer between the two immiscible liquid-liquid phases (triglycerides and alcohol) in transestrification reactions. Considering these aspects, some of the process-intensification technologies that have recently been developed are static mixers [14,15], Oscillatory flow reactors [16], micro reactors [17], microwave reactors [18][19][20], membrane reactors [21,22], reactive distillation reactors [23,24], centrifugal contactors [25], shear reactors [12,26], ultrasonic reactors [27][28][29], and hydrodynamic cavitation reactors with constriction [30][31][32].…”