Two‐phase production of cyclohexene and cyclooctene oxides in water as an approach to pollution prevention

Abstract

Liquid-liquid two-phase epoxidation from cyclohexene and cyclooctene in aqueous potassium peroxymonosulfate (commercially available as Oxone  ) solution was studied as an application in pollution prevention. To avoid potential emissions of volatile organic compounds an aqueous solution was employed to replace the usual chlorinated solvents used in epoxide production. A droplet column reactor and stirred tank reactor were used to investigate two-phase synthesis of epoxide. An aqueous Oxone  solution was used to oxidize a dispersion of alkene droplets and form epoxide. The study of aqueous epoxidation in both reactors showed that the epoxidation of alkenes can be represented as a first order reaction with respect to alkene. The salting out effect of Oxone  concentration was studied in both reactors and found to be very similar at optimal conditions. In comparing the two reactors, it was found that the droplet column reactor produces larger quantities of product per unit reactor volume for the same reaction time. The objective of this study is to provide an alternative reactor design and synthesis route that can meet pollution prevention goals.

Epoxidation of Olefins Catalyzed by Sulfate‐based Supramolecular Ion Pairs

“…The [HSO 5 ] À anion is, however, a well-known oxidant known as Oxone, K[HSO 5 ] (stabilized by KHSO 4 and K 2 SO 4 ), which is widely applied as a stoichiometric oxidant in metal-free Shi-type epoxidations with ketones as catalysts in organic phase [3c,11,12] and even in water. [13,14] In these cases, the byproduct sulfate cannot be recycled into the [HSO 5 ] À anion in a catalytic fashion, i. e., sulfate is a stoichiometric waste product of Oxone. This shortcoming, together with our results in the application of element-oxo anions in supramolecular epoxidations has led us to study the potential of the sulfate anion as catalyst for the epoxidation of olefins in organic phase using aq.…”

“…Hence, it is not surprising that in the literature sulfate itself has not been used as a selective epoxidation catalyst in water. The [HSO 5 ] − anion is, however, a well‐known oxidant known as Oxone, K[HSO 5 ] (stabilized by KHSO 4 and K 2 SO 4 ), which is widely applied as a stoichiometric oxidant in metal‐free Shi‐type epoxidations with ketones as catalysts in organic phase [3c,11,12] and even in water [13,14] . In these cases, the byproduct sulfate cannot be recycled into the [HSO 5 ] − anion in a catalytic fashion, i. e., sulfate is a stoichiometric waste product of Oxone.…”

Influence of pollutant concentration on the separation efficiency of chelating membranes for removing simultaneously metal ions and proteins from simulated industrial wastewater

“…With global rapid economic growth, the widespread popularity of industrialization and the increasing degree of urbanization, a great deal of industrial wastewater is generated every day. If it is arbitrarily discharged without any treatment, it will cause significant harm to the water environment 1‐3 . Industrial effluent usually contains not only a large number of metal ions such as Cu(II), 4 Pd(II), 5 Cr(II), 6 Mn(II) 7 and Hg(II), 8 but also many kinds of organic pollutants, 9,10 including pesticides, 11 phenols, 12 aldehydes, 13 polysaccharides, 14 proteins, 15 petroleum pollutants, 16 etc.…”