An experimental investigation of biodiesel synthesis from waste canola oil using supercritical methanol

-This study evaluated the potential of macauba pulp oil (MPO) as a feedstock for continuous ester production using ethanol under pressurized conditions. Experiments were performed in order to obtain data for the effect of process variables on ethyl ester (FAEE) and free fatty acid (FFA) conversion in a catalyst-free process. From the results, it appears that the MPO to ethanol mass ratio and the pressure were the variables with more favorable effect on the evaluated response variables. The addition of n-hexane caused an increase in the production of esters; however, this had a negative effect on FFA conversion. The addition of water was unfavorable for oil processing with high acidity. In this process, esterification and transesterification occur simultaneously, and the high FFA content in MPO provides high yields (85 wt% of esters; 93% FFA conversion) at low temperature, since the esterification reaction rate is higher than the transesterification. The decomposition of fatty acids was evaluated and levels <5% were observed under the evaluated experimental conditions.

Section: Methodsmentioning

confidence: 99%

Assessment of process variables on the use of macauba pulp oil as feedstock for the continuous production of ethyl esters under pressurized conditions

Colonelli

Trentini

Santos

et al. 2017

“…At 598 K, Figure 5(b), the decomposition values at 52.5 min of residence time decreased from 15 wt% to 11.8 wt% with the addition of 10 wt% of water. Lee et al (2012) investigated the synthesis of biodiesel from waste canola oil, and reported that side reactions occurred in the reaction between glycerol and supercritical methanol at 543 K/10 MPa. The experimental results showed that these reactions could positively affect the overall biodiesel yield by providing oxygenated compounds such as 3-methoxy-1,2-propanediol, dimethoxymethane and 2,2-dimethoxypropane.…”

Section: Effect Of Water Additionmentioning

confidence: 99%

Continuous catalyst-free production of esters from Jatropha curcas L. oil under supercritical ethanol

Silva

Colonelli

Silva

et al. 2014

-In the present study, the transesterification of Jatropha oil in a continuous catalyst-free process using supercritical ethanol was investigated. Experiments were performed in a packed-bed tubular reactor by studying the effect on the reaction of temperature, pressure, water and cosolvent (n-hexane) concentrations, keeping the oil:ethanol mass ratio fixed at 1:1 for different residence times. The results demonstrated that temperature and pressure had a positive effect on fatty acid ethyl ester (FAEE) production and it was observed that the free fatty acids present in vegetable oil promote faster reaction kinetics due to simultaneous esterification and transesterification reactions. The addition of water and a cosolvent increased the FAEE yields at 573 K and 20 MPa. Within the experimental ranges investigated, water and the cosolvent decreased the decomposition of fatty acids. Appreciable reaction yields (~90 wt%) were achieved at 573 K, 20 MPa, with an oil:ethanol mass ratio of 1:1 and 10 wt% water.

“…In the ethanolysis of soybean oil at oil to ethanol molar ratio of 1:20, 20 MPa, 573 K and 45 of residence time, Silva et al (2010) obtained yields on the order of 50 wt%, while for an oil to methanol molar ratio of 1:40 the authors report 58 wt% conversion of soybean oil to ethyl esters. Lee et al (2012) evaluated the effect of the oil to methanol molar ratio on the transesterification of waste canola oil in batch mode and found that the oil to methanol molar ratio showed a positive effect on the methyl ester yield in the range of 1:20 -1:40. For oil to methanol molar ratios of 1:20 and 1:40 yields on the order of 4.4 wt% and 24.5 wt% in methyl esters are reported by the authors at 517 K and 45 min of reaction.…”

Section: Oil To Alcohol Molar Ratiomentioning

confidence: 99%

“…Marulanda et al (2010) reported that the byproduct glycerol is thermally decomposed or is consumed upon formation by methanol to produce ethers under supercritical conditions. in the synthesis of biodiesel from waste canola oil, Lee et al (2012) reported that a side reaction was obtained by reacting glycerol and supercritical methanol at 543 K/10 MPa. The experimental results showed that these reactions could positively affect the overall biodiesel yield by providing oxygenated compounds such as 3-methoxy-1,2-propanediol, dimethoxymethane, and 2,2-dimethoxypropane, as well as methyl palmitate and methyl oleate.…”

Section: Decomposition Of Fatty Acidsmentioning

confidence: 99%

Biodiesel production through non-catalytic supercritical transesterification: current state and perspectives

Silva

Oliveira

2014

-The inconveniences of the conventional method for biodiesel production by alkaline catalysis suggests research towards alternative methods, with the non-catalytic transesterification using an alcohol at supercritical conditions proposed as a promising technique for biodiesel production. The so-called supercritical method (SCM) has powerful advantages over conventional techniques, such as fast reaction rates, feedstock flexibility, production efficiency and environmentally friendly benefits. However, application of this methodology has some limitations, like operating conditions (elevated temperature and pressure and higher amounts of alcohol), which result in high energy costs and degradation of the products generated. In this review paper the state of the art in relation to the use of the SCM for biodiesel production is reported and discussed, describing the characteristics of the method, the influence of operational parameters on the ester yield, patents available in the field and the perspectives for application of the technique.