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Biodiesel is an environmentally friendly, renewable new alternative energy, poor storage stability of biodiesel is inadequate. Add a variety of antioxidants can improve the stability of biodiesel. In this study, we designed a new type of stabilizer gallate terpene alcohol esters of gallic acid terpene alcohol ester synthesis and structural identification, stability evaluation of biodiesel preparation with gallic acid alkyl esters, synthetic antioxidants, natural anti- oxidants and complex stabilizer comparative study, based on the study of gallic acid terpene alcohol esters for biodiesel temperature stability and high temperature stability, and to explore terpene alcohols gallic acid esters for biodiesel stabilizer stabilization mechanism. This study was to explore the molecular structure and properties stabilizer relations and efficient screening of biodiesel stabilizer to provide an initial basis. A new gallic acid terpene alcohol ester synthesis routes, namely: gallic acid first by acetylation protection, respectively, and six kinds of terpene alcohols at room temperature ultrasonic-assisted DCC (N, N'-dicyclohexyl carbodiimide) dehydration esterification, and then hydrazine hydrate deacetylation, to generate the corresponding gallic acid esters of terpene alcohols. The resulting six kinds of synthetic gallic acid esters of terpene alcohols undergo structural identification. The method of low reaction temperature, the reaction time is short, high yield. Gallic acid, acacia ester, gallic acid geranyl acetate, gallic acid, linalyl acetate, gallic lime flowers tertiary alcohol ester, gallic acid menthol ester and gallic acid, hydrogenated loose alcohol esters of total yield were 86.2%, 85.3%, 76.3 %, 87.5%, 79.2% and 82.5%. Seeking a suitable carrier biodiesel stability studies carried out at room temperature low power density of ultrasonic assisted transesterification of biodiesel, soybean oil and methanol molar ratio of 1:6 (mol / mol), potassium hydroxide the mass ratio of soybean oil and 0.01:1 (g / g), the ultrasonic power density 0.032 W · cm-3, the reaction time ultrasound 20 ~ 60 min, the reaction temperature is 30 ℃, biodiesel yield 86.4% ~ 85.9% ( Refractive index method), the quality of the resulting biodiesel to meet the requirements. Biodiesel peroxide value, acid value and a refractive index of evaluation index of the gallic acid esters such as terpene stabilizer on the temperature stability of biodiesel. Its stabilizing effect on the size of the order: gallic acid acacia ester gt; gallate Linalyl gt; gallic lime flowers tertiary alcohol ester gt; gallic acid menthyl gt; gallic acid, geranyl acetate gt; gallic acid hydroabietyl alcohol ester . At 6 months, gallic acid ester and acacia methyl gallate inhibition rates were 31.7% and 76.6%, collaborative synergist can gallic acid citrate acacia ester inhibition rate increased to 74.1%. The acid value of biodiesel evaluation studied terpene alcohols gallic acid esters heat stabilizers on the stability of biodiesel. 6 kinds of gallic acid esters of terpene alcohols effect on the high temperature stability of biodiesel little difference which Geranyl gallic acid and gallic acid esters acacia slightly better temperature stabilization effect. Stability derived regression equations discussed terpene alcohols gallic acid esters for biodiesel stabilization mechanism.
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