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Jatropha (Jatropha curcas) oil with iodine value 104 g I 2 /100 g, and containing 44.7% oleic acid and 31.4% linoleic acid, was epoxidised in situ with hydrogen peroxide (30%) and acetic/formic acid in the presence of catalytic amounts of sulphuric acid. We have compared the kinetics of epoxidation of jatropha oil (JO) by peroxyacetic and peroxyformic acids, in or without toluene at 30, 50, 70, and 85• C. The effects of temperature and various mole ratios on epoxidation rate, oxirane ring stability, and iodine value of the epoxidised oil were studied, and optimum conditions were established. The rate constants for epoxidation of JO were found to be in the range 0.22-69.4 × 10 −6 l.mol −1 .s

Epoxidation of karanja (Pongamia glabra) oil catalysed by acidic ion exchange resinKaranja oil with an iodine value of 89 g/100 g was epoxidised in situ with aqueous hydrogen peroxide and acetic acid in the presence of Amberlite IR-120 acidic ion exchange resin as catalyst. The effect of the operating variables on the oxirane oxygen content, as well as on the oxirane ring stability and the iodine value of the epoxidised karanja oil, were determined. The variables studied were stirring speed, hydrogen peroxide-to-ethylenic unsaturation molar ratio, acetic acid-to-ethylenic unsaturation molar ratio, temperature, and catalyst loading. The effects of these parameters on the conversion to the epoxidised oil were studied and the optimum conditions for the maximum oxirane content were established. The proposed kinetic model takes into consideration the two side reactions, namely, epoxy ring opening involving the formation of hydroxy acetate and hydroxyl groups, and the reaction between the peroxyacid and the epoxy group. The kinetic and adsorption constants of the rate equations were estimated by the best fit using Marquardt's algorithm. Good agreement between experimental and predicted data validates the proposed kinetic model. From the estimated kinetic constants, the apparent activation energy for the epoxidation reaction was found to be 11 kcal/mol. Keywords: Epoxidation, peroxyacetic acid, karanja oil (Pongamia glabra), acidic ion exchange resin, kinetics.Eur. J. Lipid Sci. Technol. 109 (2007) 575-584 DOI 10.1002/ejlt.200600298 575 IntroductionEpoxidation of plant oils (triacylglycerols), commonly referred to as "vegetable oils", is a commercially important reaction as the epoxides obtained from these renewable resources, and from their transesterification products, have wide applications in materials such as plasticisers and polymer stabilisers [1][2][3].Fats and oils are renewable resources that can be treated chemically or enzymatically to produce materials that can often act as replacement for materials derived from petroleum. Fatty epoxides can be used directly as plasticisers that are compatible with polyvinyl chloride (PVC) and stabilisers for PVC resins to improve flexibility, elasticity, and toughness and to impart stability to the polymer towards heat and UV radiation. Due to the high reactivity of the oxirane ring, epoxides also act as a raw material for a variety of chemicals, such as alcohols, glycols, alkanolamines, carbonyl compounds, olefinic compounds, and polymers like polyesters, polyurethanes, and epoxy resins. Epoxidised oil with a higher oxirane oxygen value and a lower iodine value is considered to be of better quality [4][5][6]. Today, one of the most important epoxidised vegetable oils is epoxidised soybean oil (ESO), and its worldwide production is about 200,000 t/year [7].On an industrial scale, the epoxidation of plant oils is currently carried out with the "Prileschajew reaction", in which the unsaturated oils react with a percarboxylic acid, such as peroxyacetic acid or peroxyf...

In this work, zeolite-based sorbents were developed from gasified rice husk. CO2 capture capacity of the sorbents was examined at various temperatures and pressures employing a fixed-bed flow reactor and simulated flue gas. Various physicochemical properties such as thermal stability, pore size distribution, morphology, chemical composition, etc. of the in-house-developed materials were characterized in detail and were also compared with two commercially available zeolites. Tetra-ethylenepentamine was impregnated in the in-house-developed zeolite supports to investigate its suitability to improve the CO2 adsorption capacity. The effects of reactor pressure, temperature, Si/Al ratio, and amine loading on CO2 uptake capacity were examined. A declining trend in CO2 adsorption capacity was observed with the increase in adsorption temperature and amine loading. At 30 °C, zeolite-Y (designated as Z-Y-3, silica to alumina ratio of 2.25) sample exhibited maximum adsorption capacity, and the obtained values were around 114 and 190 mg CO2/g sorbent under atmospheric and 5 bar pressure, respectively. It was also observed that the presence of alkali metal ions influenced the adsorption capacity of the zeolites. The study inferred that the adsorbent was efficient and promising for multiple adsorption–desorption cycles without much deterioration of the capture capacity.