An alternative method by pressurized DSC to evaluate biodiesel antioxidants efficiency

Leonardo, R. S.; Valle, M. L. Murta; Dweck, Jo

doi:10.1007/s10973-011-2175-4

Cited by 19 publications

(7 citation statements)

References 34 publications

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“…However, several alternatives methods were proposed to increase the knowledge about a particular sample, adding with information obtained from more classical analyses such as titration of peroxide, iodine, and acid values [ 36 ]. Other methods, such as infrared spectroscopy, PetroOXY, ultrasonic-accelerated oxidation, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) [ 8 , 37 ], have been also recently applied to monitor the biodiesel quality. Each of these techniques can provide specific sample diagnostic which they should be crossed and interpreted to obtain a detailed picture of the biodiesel quality condition.…”

Section: Resultsmentioning

confidence: 99%

Fluorescence Spectroscopy Applied to Monitoring Biodiesel Degradation: Correlation with Acid Value and UV Absorption Analyses

Vasconcelos

Passos

Lescano

et al. 2018

Journal of Analytical Methods in Chemistry

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The techniques used to monitor the quality of the biodiesel are intensely discussed in the literature, partly because of the different oil sources and their intrinsic physicochemical characteristics. This study aimed to monitor the thermal degradation of the fatty acid methyl esters of Sesamum indicum L. and Raphanus sativus L. biodiesels (SILB and RSLB, resp.). The results showed that both biodiesels present a high content of unsaturated fatty acids, ∼84% (SILB) and ∼90% (RSLB). The SILB had a high content of polyunsaturated linoleic fatty acid (18 : 2), about 49%, and the oleic monounsaturated (18 : 1), ∼34%. On the other hand, RSLB presented a considerable content of linolenic fatty acid (18 : 3), ∼11%. The biodiesel samples were thermal degraded at 110°C for 48 hours, and acid value, UV absorption, and fluorescence spectroscopy analysis were carried out. The results revealed that both absorption and fluorescence presented a correlation with acid value as a function of degradation time by monitoring absorptions at 232 and 270 nm as well as the emission at 424 nm. Although the obtained correlation is not completely linear, a direct correlation was observed in both cases, revealing that both properties can be potentially used for monitoring the biodiesel degradation.

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Section: Resultsmentioning

confidence: 99%

Fluorescence Spectroscopy Applied to Monitoring Biodiesel Degradation: Correlation with Acid Value and UV Absorption Analyses

Vasconcelos

Passos

Lescano

et al. 2018

Journal of Analytical Methods in Chemistry

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“…Trata-se de um parâmetro importante no que se refere à qualidade do biodiesel, pois quanto maior a sua estabilidade, melhor o seu comportamento durante o armazenamento e transporte, o que influencia positivamente na sua comercialização. [156][157][158] A qualidade do biodiesel pode ser comprometida durante a estocagem por vários fatores como: (a) oxidação térmica; (b) oxidação induzida ou não pela presença de elementos metálicos; (c) hidrólise; e (d) crescimento microbiano via bactérias ou fungos. 5,156,[159][160][161][162] As espécies químicas formadas durante a degradação, além de comprometerem a qualidade do biodiesel, são corrosivas e podem causar depósitos em tanques de combustível, sistemas de bombeamento, filtros e outras partes internas do motor.…”

Section: Estabilidade à Oxidaçãounclassified

Biodiesel: Raw Materials, Production Technologies and Fuel Properties

Ramos

2017

Rev. Virtual Quim.

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The entire biodiesel production chain developed tremendously in regions all over the world and this biofuel has established itself as one of the main alternatives to replace petroleumderived fuels. Several studies have already demonstrated its compatibility with diesel oil and the international standards have evolved to ensure safety and satisfaction to the end-users. Although already losing priority in stronger economies such as United States, Germany and France, this production chain is still expanding considerably in emerging economies such as Brazil, where it has been established as a project of great scientific, technological, political and economic interests. In this article, important aspects of the biodiesel production and use are revised in detail, particularly in relation to the availability of suitable raw materials in large scale as well as to the chemistry involved in the technologies available to date for its conversion to biofuels that are fully compatible with diesel fuel applications.

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“…Besides, the maintenance of good oxidation stability during fuel storage and transportation positively influences its commercialization. 6,40,41 Oxidation stability is expressed by the induction period (IP), which is measured in a Rancimat apparatus when the sample is exposed to a constant air flow at 110 °C. 42,44,45 In this way, fatty acids are oxidized releasing volatile secondary reaction products that are captured in distilled water whose electrical conductivity is continually recorded.…”

Section: Introductionmentioning

confidence: 99%

“…The oxidation stability of biodiesel is defined as its resistance to physical and chemical changes that are caused by accelerated oxidation conditions, and this is regarded as an important parameter for ensuring biodiesel quality. Besides, the maintenance of good oxidation stability during fuel storage and transportation positively influences its commercialization. ,, Oxidation stability is expressed by the induction period (IP), which is measured in a Rancimat apparatus when the sample is exposed to a constant air flow at 110 °C. ,, In this way, fatty acids are oxidized releasing volatile secondary reaction products that are captured in distilled water whose electrical conductivity is continually recorded. A sudden rise in conductivity indicates sample degradation, and the IP value is calculated from the inflection point of this exponential curve.…”

Section: Introductionmentioning

confidence: 99%

Bifunctional Additives To Improve the Cold Flow Properties and Oxidation Stability of Soybean Oil Biodiesel

et al. 2020

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Biodiesel is a well-established biofuel that contains unsaturated and saturated fatty esters, and their contents influence oxidation stability and solidification properties, respectively. Also, these properties can be aggravated during use after long-term storage. In this research, a new class of antioxidant/antifreeze bifunctional additives was developed by copolymerization of monomers containing an active site for addition reactions. Hydroquinone was added to these active sites after polymerization, and this chemical modification improved the performance of the additive as an antioxidant and pour point depressant of soybean oil biodiesel. This unique class of bifunctional additives was more soluble in biodiesel than hydroquinone and polymethacrylates at the same molar concentrations. The best performance was obtained by poly(oleyl acrylate-co-stearyl acrylate hydroquinone), which improved the pour point of neat biodiesel (B100) by 10 °C using a charge of just 1000 mg/kg. Also, hydroquinone performed as good as dodecyl acrylate as the pendent group, hindering crystal growth while improving B100 oxidation stability.

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An alternative method by pressurized DSC to evaluate biodiesel antioxidants efficiency

Cited by 19 publications

References 34 publications

Fluorescence Spectroscopy Applied to Monitoring Biodiesel Degradation: Correlation with Acid Value and UV Absorption Analyses

Fluorescence Spectroscopy Applied to Monitoring Biodiesel Degradation: Correlation with Acid Value and UV Absorption Analyses

Biodiesel: Raw Materials, Production Technologies and Fuel Properties

Bifunctional Additives To Improve the Cold Flow Properties and Oxidation Stability of Soybean Oil Biodiesel

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