Catalytic developments in the epoxidation of vegetable oils and the analysis methods of epoxidized products

Abstract

Epoxidation of vegetable oils by different means to improve their functional properties and to replace the harmful phthalate plasticizers along with their analysis are shown.

The Lord of the Chemical Rings: Catalytic Synthesis of Important Industrial Epoxide Compounds

“…The first reported epoxidation procedure was reported by Prilezhaev in 1906 [60]. This method, which was patented already in 1946 [55] and which is still widely used, utilizes an in situ formed peroxycarboxylic acid such as performic or peracetic acid, and the oxidant hydrogen peroxide. It works in the following way-the peracid is formed by oxidation of the carboxylic acid with a peroxide, whereafter the peracid converts the double bond into an oxirane ring (the epoxide).…”

“…Vegetable oils can be chemically modified in numerous ways, such as transesterification, epoxidation, hydroxylation, carboxylation, halogenation, hydrogenation, and oxidation. However, their epoxidation has gained a lot of attention due to the high reactivity of the epoxide group [55].…”

“…The classical Prilezhaev epoxidation has been studied by different aspects in several groups since then. There are approximately 30 review papers concerning vegetable oil epoxidationthe most recent dealing with a general overview of synthetic approaches [13], catalytic epoxidation and analysis of products [55], end-product related i.e., lubrication [56] There are approximately 30 review papers concerning vegetable oil epoxidationthe most recent dealing with a general overview of synthetic approaches [13], catalytic epoxidation and analysis of products [55], end-product related i.e., lubrication [56] or bio-resin [57], and process intensification-related i.e., microwave-assisted epoxidation [58]. Some reviews focus on the type of vegetable oil that is used, i.e., tall oil [59].…”

Slug flow as tool for selectivity control in the homogeneously catalysed solvent-free epoxidation of methyl oleate

“…Given the definition of the phase ratio PR according to formula (7), the volume-specific interfacial area available for mass transfer inside the slug flow reactor is proportional to the sum of the areas of all slugs A Slug,tot , which may be calculated from the volume of the reactor V Reactor and the inner diameter of the reactor D Reactor using formula (8). Assuming the width of the wall film h is very small compared to the capillary diameter and the side of the slugs do not offer surface area for mass transfer, formula (8) may be simplified to yield formula (9). Using the simplified formula it can be estimated that the specific area available for mass transfer lies between 36 -250 m 2 /m 3 , depending on slug length and phase ratio setting.…”

“…Consequently, corrosion might be an issue, and neutralization and separation of the acid are required before subsequent conversion of the product. Therefore, epoxidation routes based on transition metals or enzymes are highly favourable [9,10]. The oxidant, hydrogen peroxide, is directly used without the formation of percarboxylic acids resulting in non-acidic, non-corrosive conditions.…”