Optimization of reaction variables in situ transesterification of Jatropha curcas seed oil for biodiesel production

Biodiesel was produced from seed oil of Jatropha curcas by in situ acid-catalyzed transesterification with methanol. Optimization of the reaction parameters was carried out using response surface methodology based on Box-Behnken design. All the four variables investigated were found to be significant. The empirical model obtained adequately expresses the relationship between the biodiesel yield and the statistically significant reaction variables (R2 = 96.97%). The optimization result predicted an optimal biodiesel yield of 84.07% at a reaction temperature of 48°C; a reaction time of 240 min; with 5 cm3 methanol/g of the seed and catalyst concentration of 0.88M. The validation result was in agreement with the predicted biodiesel yield. The fatty acid methyl profile of the biodiesel shows that it predominantly contains methyl esters of octadecenoic acid, octadecadienoic acid and hexadecanoic acid which make up about 87% the biodiesel. The fuel properties of the biodiesel were in agreement with the requirements of Worldwide Fuel Charter Committee Biodiesel Guidelines.Keywords: Jatropha curcas, Biodiesel, In situ transesterification, Optimization, Box-Behnke

Lupeol Acetate Isolated from n-Hexane Extract of Tapinanthus globiferus Leaf

A study was carried out to isolate and characterise Lupeol Acetate from the leaves of Tapinanthus globiferus. The dried pulverized plant material was extracted for 24 hours with n-hexane, dichloromethane, ethyl acetate and methanol solvents. The /n-hexane fraction obtained was subjected to column chromatography followed by preparative thin layer chromatography, which resulted in isolation of a colourless crystalline compound. The spectral data (1H NMR, 13C NMR and FTIR) and literature comparison infer that the isolated compound is a pentacyclic triterpenoid namely Lupeol Acetate.Keywords: Tapinanthus globiferus, Lupeol Acetate, Structure elucidatio

Про неперіодичні групи з недедекіндовою нормою абелевих нециклічних підгруп

Non-periodic groups without free Abelian subgroups of rank 2 with non-Dedekind norm of Abelian noncyclic subgroups are studied.Вивчаються неперіодичні групи без вільних абелевих підгруп рангу 2, норма абелевих нециклічних підгруп яких недедекіндова

Phytochemical studies and elemental analysis of the root bark of Piliostigma thonningii(Schum.) obtained in Sokoto

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