Hydrogen peroxide is an ideal oxidant for industrial processes that produce useful chemicals such as propylene oxide, oxime and catechol because this environmentally benign oxidant has excellent oxygen atom efficiency and low cost. However, hydrogen peroxide is a weak oxidant with low selectivity, so application of hydrogen peroxide oxidation technology to the synthesis of complex organic compounds containing various functional groups remains challenging. We have found that various methods of hydrogen peroxide oxidation of olefins can be used to synthesize a wide range of fine chemicals. Here we report our recent investigations of a practical synthetic method that uses common metals and reusable catalysts to expand our previous catalytic system using tungsten-based catalysts using three components. For example, our new method employs high-speed styrene oxide synthesis using an iron picolinate catalyst, bulky sulfide oxidation employing a reusable titanosilicate zeolite catalyst, and high-conversion synthesis of nitroxide radical polymer. The desired compounds are formed in over 90 % selectivity despite their complex structures, under safe reaction conditions and with the high efficiency of hydrogen peroxide.
Biodiesel fuel (BDF) was produced by using CaO-loaded alginate capsules via rapeseed oil transesterification with methanol. Analysis of the solid and liquid phases in the CaO-loaded alginate capsules suggested that the main factors for the high BDF yield were the accumulation of fatty acid methyl esters (FAME) in the capsules and the formation of an active glycerin–CaO phase. Moreover, rapeseed oil methanolysis to FAME occurred with CaO-photothermal exchange material-loaded alginate capsules under light irradiation. The increase in the irradiation power increased the temperature inside the capsules, which resulted in a higher BDF yield. CaO (100 mg/g-oil)-active carbon (0.5 mg/g-oil)-loaded capsules showed the best performance (BDF yield: 60 % for 1 h and 90 % for 6 h) among the capsules under light irradiation with a full wavelength range (3.6 W). Under these reaction conditions, the FAME phase contained only 0.37 % Ca from the CaO catalyst with a capsule breakage rate of 53 %.
Crude oil dehydration is an important requirement in oil and gas processing. Most of the conventional chemical demulsifiers are effective in resolving water-in-oil (W/O) emulsions but their application is restricted due to environmental concerns. The chemical demulsifiers are toxic and may cause serious environmental degradation during water disposal. In this study, we have investigated extracts of green tea and some vegetable oils such as the olive and coconut oils as potential environment-friendly W/O demulsifiers. The plant extract was obtained by Soxhlet extraction method while the vegetable oil triglycerides was obtained from 100 % coconut oil. The purity and compositions of the extracts and the vegetable oils were obtained with high temperature gas chromatography (HTGC) while the toxicity tests were also carried out to ascertain the eco-friendliness of the tested potential demulsifiers. The melting point of the water-insoluble and unreactive coconut oil was 76 °F while its specific gravity was 0.9. Subsequently, bottle tests were conducted under static and dynamic conditions to select the best demulsifier among the extract and the vegetable oils. Results showed that the coconut oil gave a higher volume of separated water than the green tea extract and olive oil for all W/O emulsion samples.
Hydrogen generation via dehydrogenation of formic acid using an immobilized Ir-complex catalyst, which combines the catalytic ability of the homogeneous catalyst and ease in handling of the heterogeneous catalyst, was investigated. The immobilization process was analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption-desorption measurement. Analytical methods for the heterogeneous catalyst remained appropriate for immobilized catalyst analysis. Hydrogen generation using the immobilized catalyst showed the same activation energy (Ea = 72.5 kJ mol−1) as the analogous homogeneous catalyst (Ea = 72.1 kJ mol−1). However, the reaction rate for the immobilized catalyst was 70 % of that achieved for the homogeneous catalyst because of the reduced collision frequency. The ζ potential measurement implied that immobilized catalyst did not form a stable dispersion during the catalytic reaction. Effective agitation control is needed for efficient dehydrogenation reaction using immobilized catalyst. Immobilization of the homogeneous catalyst represents a new technology for practical hydrogen generation.
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