GB1311554A - Isomerization of hydrocarbons - Google Patents

Abstract

1311554 Purifying and isomerizing hydrocarbons GULF RESEARCH & DEVELOPMENT CO 8 July 1970 33037/70 Heading C5E Prior to isomerization in the presence of a catalyst comprising a major proportion of alumina and a minor proportion of a hydrogenating metal, a hydrocarbon feedstock containing impurities which cause deactivation of the isomerization catalyst is treated to remove such impurities by passage through a plurality of adsorption zones, at least one of which contains a zeolitic molecular sieve adsorbent and at least one other of which contains an auxiliary solid adsorbent other than a molecular sieve. The feedstock, e.g. a cyclic or acyclic paraffin, may be contacted with the adsorbents in either order. Suitable molecular sieves are synthetic X zeolites and natural faujasites, and preferably a 13X zeolite optionally admixed with a 10X or 4A zeolite. Suitable auxiliary adsorbents are clays, carbon, alumina, magnesia, silica, silica-alumina and silica-magnesia, preferably Attapulgus clay. Examples show the improvement in the life of a Pt/Al 2 O 3 catalyst when isomerization of n-butane is conducted in the presence of hydrogen, the feed having been purified by passage through Attapulgus clay and 13X molecular sieve alone or mixed with a small amount of 4A molecular sieve.