Epoxidation of vegetable oils using the heterogeneous catalysis, amorphous Ti-SiO2

Epoxidation of the double bond is an interesting reaction because it opens up a wide variety of reactions that can be carried out under mild conditions. The formed epoxide is an intermediate that can be converted to a variety of products by the addition of nucleophiles to form lubricants because of high reactivity of the oxirane ring and the physical and chemical properties can be changed depending upon the kind of nucleophiles are added. For example, alkoxy alcohol, hydroxy ester, amino alcohol, hydroxynitrile, etc. can be produced by reaction of epoxide with different nucleophile. In industry, the epoxidation of plant oils has been already carried out homogeneously with a percarboxylic acid, such as peracetic acid and performic acid, obtained by oxidation with hydrogen peroxide, using mineral acid, like sulfuric acid, as catalyst. However, there are several drawbacks in the process: (i) high selectivity of epoxidation is not achieved due to acid-catalysed oxirane ring opening reaction; (ii) the separation of acidic by-products is difficult; (iii) the handling of concentrated hydrogen peroxide and strong acids is dangerous and causes corrosion problems and additionally, they are environmentaly harmful. Thus, recently, a lot of interests of academia researchers and chemical companies have been made on the catalytic processes in order to overcome these disadvantages. Even though many investigations in this field have been carried out already, there are still many possibilities in developing higher efficiency and economical benefit and new ways for environmentally friendly reactions. The aim of this thesis is to investigate the heterogeneously catalyzed epoxidation of vegetable oils, like oleic acid methyl ester and oleic acid, in a batch-reactor. The scope of this work includes the preparation and analysis of amorphous Ti-SiO2 catalysts using different silica sources and different methods. Furthermore, scaling-up of the reaction was carried out and the efficiency was compared with that in small scale one. Additionally, the separation of product from the reaction mixture by distillation was briefly tested in order to see the possibility of the re-cycling process