Abstract: A process for producing styrene by the dehydrogenation of ethyl benzene whereby the ethyl benzene in a mixture with steam is introduced into a tubular reactor, the tubes of which are heated by molten salts. The structural parameters of this process are the tube diameter which should be 20 to 35 millimeters, the temperature of the molten salts which should be 580.degree. to 660.degree. C. and at most 20.degree. C. higher than the reaction temperature at the catalyst and the weight ratio of steam to ethyl benzene of the feed stock which should be 0.5 to 1. The process saves energy and increases efficiency by reducing the steam consumption.

Abstract: The invention relates to a process of converting ethylbenzene to styrene by catalytic dehydrogenation at temperatures of about 600.degree. C. in the presence of water vapor in a tubular reactor. The heat required for the dehydrogenation is fed to the tubular reactor with a molten salt bath. The dehydrogenation is effected isothermally and in a single stage under atmospheric pressure or preferable under a subatmospheric pressure with a water vapor-ethylbenzene ratio of 1.2 to 1.5 kg of water vapor per kg of ethylbenzene. The temperature of the ethylbenzene-water-vapor mixture entering the tubular reactor is maintained 50.degree. to 100.degree. C. below the temperature of the molten salt bath.