Abstract: The invention is related to petrochemistry and is useful in the process of combined production of phenol and acetone by the cumene method. The method is a two stage process which minimizes waste water volume, diminishes equipment corrosion and minimizes consumption of cumene. In the first stage, the phenol tar is treated with a 2-5% water solution of a water soluble amine at a ratio of 1:1.5-1:4.0 to produce two layers, water and organic. At the second stage the water layer from the first stage is thermotreated. As a result, water soluble amino phenate decomposes to amine and phenol. Gaseous amine is removed from the system and then recycled to the first stage. The phenol water solution obtained from the thermotreatment is extracted by standard extraction agents (e.g. diisopropylether, cumene).The water layer from the phenol extraction is about 50-95% of the original water solution employed in the first stage and is then saturated with the amine and recycled to the first stage.

Abstract: A method for preparing C.sub.3 -C.sub.4 olefins and vinylaromatic compounds, viz. styrene, vinyltoluenes or vinylxylenes which comprises alkylation of toluene or methyl derivatives thereof with a C.sub.2 -C.sub.3 olefin into the methyl group. The resulting alkylaromatic compounds are subjected to conversion to the desired products in the presence of ethylene on a catalyst consisting of chromium oxide, tungsten oxide and an oxide of an alkali or alkali-earth metal supported by a carrier.The method according to the present invention makes it possible to increase the yield of vinylaromatic compounds, obtain individual isomers of vinyltoluene or vinylxylene and efficiently utilize the part of the alkyl radical of the alkylaromatic compound lost in the prior art method.

Abstract: A method and catalyst for preparing styrene which comprises dehydrodimerization of toluene, followed by conversion of the resulting dehydrodimerization products to styrene. The conversion is conducted in the presence of ethylene using a catalyst consisting of chromium oxide, tungsten oxide and an alkali metal oxide supported by a carrier. The method according to the present invention makes it possible to increase the yield of styrene and simplify the process technology.