Optimization of Alkali-Catalyzed Transesterification of Brassica Carinata Oil for Biodiesel Production

Abstract

Environmental concerns are driving industry to develop viable alternative fuels from renewable resources. On the other hand, to reduce food surplus, the Agricultural Policy of the European Union (EU) obliges the European farmers to leave a percentage of the arable land as set-aside, where can be grown, as an exception, vegetables for nonfood purposes, i.e., energetic ones. Currently, fossil fuels are used in diesel engines and are essential in industrialized places. In addition, petroleum-based diesel increases environmental pollution. To solve these problems, transesterified vegetable oil that has been grown in set-aside lands can be considered to be a renewable energy resource. In this sense, this work describes the optimization of the parameters involved in the transesterification process of Brassica carinata oil. Gas chromatography was used to determine the fatty acid composition of Brassica carinata oil and its esters. Results revealed that the free fatty acid content is a notorious parameter to determine the viability of the vegetable oil transesterification process. In this sense, it was not possible to perform a basic transesterification using Brassica carinata oil with a high erucic acid content. The transesterification process of Brassica carinata without erucic acid required 1.4% KOH and 16% methanol, in the range of 20-45°C, after 30 min of stirring. Our results suggest that the greater the presence of KOH, the lesser the methanol requirements. However, this is valid only under certain limits. Also, if the presence of KOH or methanol is lower or higher than the optimal values, the reaction either does not fully occur or leads to soap production, respectively. Based on this field trial, biodiesel from Brassica carinata oil could be recommended as a diesel fuel candidate if long-term engine performance tests provide satisfactory results.

Biodiesel de soja: taxa de conversão em ésteres etílicos, caracterização físico-química e consumo em gerador de energia

“…A identificação dos picos foi realizada através da comparação com tempo de retenção de padrões Nu-Chek, e a quantificação por normalização de área. 9,35 e, também, para evitar problemas com corrosão dos componentes do motor, que ocorrem devido à presença de traços de ácido 10 . O álcool utilizado foi o etanol isento de água (anidro) e em excesso devido ao caráter reversível da reação de transesterificação 1,34,35 .…”

“…Esta possibilidade de emprego de combustíveis de origem agrícola em motores do ciclo diesel é bastante atrativa tendo em vista o aspecto ambiental, por serem uma fonte renovável de energia 5,7,8 e pelo fato do seu desenvolvimento permitir a redução da dependência de importação de petróleo 7 . Foi constatado, porém, que a aplicação direta dos óleos vegetais nos motores é limitada por algumas propriedades físicas dos mesmos 2 , principalmente sua alta viscosidade, sua baixa volatilidade e seu caráter poliinsaturado, que implicam em alguns problemas nos motores, bem como em uma combustão incompleta 2,[9][10][11] . Assim, visando reduzir a viscosidade dos óleos vegetais, diferentes alternativas têm sido consideradas, tais como diluição, microemulsão com metanol ou etanol, craqueamento catalítico e reação de transesterificação com etanol ou metanol 2,5 .…”

“…Biodiesel was produced by the transesterification of neutral soybean oil and anhydrous ethanol using NaOH as catalyst. Combinations of biodiesel and diesel in the proportions of 0,5,10,20,40, 60, 80 and 100% were tested, respectively, as fuel in an energy generator. The average consumption and mixture performance were analysed.…”

Production optimization and quality assessment of biodiesel from waste vegetable oil

“…Alkyl oxide solutions of sodium methoxide or potassium methoxide in methanol, which are now commercially available, are the preferred catalysts for large continuous-flow production processes (Singh, et al, 2006). Biodiesel with the best properties was obtained using potassium hydroxide as catalyst in many studies (Encinar, et al, 2005;Jeong and Park, 1996;Karmee, 2005;Dorado, et al, 2004;Dorado, et al, 2002;Darnoko and Cheryman, 2000;Ugheoke, et al, 2007;El-Mashad, et al, 2006). Besides, many other studies achieved best results using NaOH (Felizardo, et al, 2006;Vicente, et al, 2004;Cheng, et al, 2004;de Oliveira, 2005).…”

The Production of Biofuels from Coconut Oil Using Microwave

“…The improvement of power increased the rate of microwave beams so that excitation occurred in the molecules. The preparation conducted above 60 o C using NaOH was not effective because of the rivalry between transesterification and saponification reactions as previously published by Dorado, et al, (2004). Therefore, the process of transesterification reaction using NaOH in microwaves should be carried out with shorter time, which was less than 60 min.…”