Hydroperoxide method for the co-production of methyl ethyl ketone and phenol

Objectives. Applying the hydroperoxide method for the co-production of methyl ethyl ketone and phenol, the work studies the kinetic and other characteristics of the individual stages of the developed process to select the optimal conditions for producing the maximum yield of intermediate and target products. Methods. The research relied on the main theoretical and methodological provisions for the synthesis of intermediate and target products of the cumene technology for the co-production of phenol and acetone. The obtained intermediate and target products were qualitatively and quantitatively analyzed according to modern physicochemical approaches. Gas–liquid chromatography was performed with a Chromatec-Crystal 5000.2 hardware and software complex. The infrared (IR) spectra of the synthesized compounds were recorded with a Spectrum RX-1 IR Fourier spectrometer. 1 H nuclear magnetic resonance (NMR) spectroscopy of substances was conducted using a Bruker DRX 400 NMR spectrometer. A quantitative determination of the content of sec -butylbenzene hydroperoxide was carried out using iodometric titration. Results. The main stages of the developed method for the co-production of methyl ethyl ketone and phenol based on the hydroperoxide oxidation of sec -butylbenzene were investigated. sec- Butylbenzene was synthesized by alkylation of benzene with 1-butanol in the presence of concentrated sulfuric acid at a yield of about 82%. The hydrocarbon compound was subjected to aerobic liquid-phase oxidation catalyzed by N -hydroxyphthalimide to the corresponding hydroperoxide with a main substance content of 30–35 wt %, feedstock conversion of 34–37%, and selectivity of hydroperoxide formation above 95%. The kinetic and other characteristics were studied for the final stage of the developed method, comprising the acid decomposition of hydroperoxide to methyl ethyl ketone and phenol. Suitable conditions for obtaining target products with high yields were identified. Conclusions. Methyl ethyl ketone and phenol of high purity with yields of 72 and 74%, respectively, were obtained by the hydroperoxide method. The structures of the synthesized substances were confirmed by IR and 1 H NMR spectroscopy.