Action of Water Vapor in the High-Temperature Hydrogenation of a Mixture of Coke-Plant Benzene and the Naphthalene Fraction of Coal Tar

In the catalytic high-temperature hydrogenation (hydrodealkylation) of a mixture of raw coke-plant benzene and the 180-230 degrees C naphthalene fraction of coal tar, water vapor (steam) acts in two ways: it blocks the smallest pores in the catalyst, from which the removal of products is difficult; and it facilitates their desorption from the large pores, thereby decreasing the likelihood of polymerization of the reactive products of intermediate hydrocracking and dealkylation. Steam is found to play a positive role in slowing the formation of high-molecular compounds, which are sources of coke deposits on the catalyst.