Patent GB-863852-A (GB)
Title: Improvements in or relating to catalysts and catalytic conversion processes
IPC: C07C4/18
Filed: 1956-08-08
Abstract: Hydrocarbon conversion processes are carried out in the presence of either (a) a catalyst base prepared by depositing nickel, cobalt or iron in elemental or combined form on an amphoteric oxide, particularly alumina, in a form having a specific area above 10 sq. metres/gram or a form which is converted by heat to a form having the desired specific area, roasting the treated amphoteric oxide at above 650 DEG C., extracting the roasted material with an inorganic acid and washing with water or (b) a complex catalyst prepared by depositing on the base (a) a catalyst component of known activity for effecting the hydrogenation of unsaturated hydrocarbons e.g. platinum, indium, palladium, nickel, cobalt, iron, chromia or molybdena (see Group III).  Reactions specified with catalyst base (a) are cracking and polymerisation and with complex catalyst (b) cracking, especially dealkylation of alkylated aromatic compounds, polymerisation and hydrogenation.  Olefines which may be polymerised over catalyst (b) by passing over the catalyst in vapour phase at elevated temperature include ethylene, propylene, butene-1, butene-2, butadiene and styrene.  Hydrocarbons which may be dealkylated include toluene, xylenes, cumene, mesitylene, pseudocumene, diethylbenzene, coal tar fractions and petroleum fractions obtained from the platforming process.  The feedstock is passed over the catalyst in the vapour phase at 250-500 DEG C. and atmospheric pressure to 200 p.s.i. in admixture with hydrogen. Hydrogenation of ethylenically unsaturated compounds such as ethylene, propylene, butene-1, butene-2, pentenes, hexenes, butadiene, diisobutylene, and propylene dimer, trimer or tetramer, oleic and linoleic acids and unsaturated alcohols or esters or aromatic compounds such as benzene, toluene, xylenes, ethylbenzene, cumene, pseudocumene, mesitylene, diphenyl and naphthalene is effected by passing over the catalyst in vapour phase with hydrogen at 200-1,000 p.s.i. and below 400 DEG C.  Under certain conditions dealkylation and hydrogenation may proceed simultaneously. Specifications 844,242 and 844,243 are referred to.ALSO:A catalyst base is prepared by depositing iron, cobalt or nickel in elemental or combined form on an amphoteric oxide, particularly alumina, in a form having a specific area above 10 sq. metres/gram or convertible by heat thereto, roasting the treated amphoteric oxide at above 650 DEG C., extracting the roasted material with an inorganic acid and washing with water.  On this base may be deposited, to give a complex catalyst, a catalyst p  component of known activity for effecting the hydrogenation of unsaturated hydrocarbons, e.g. platinum, indium, palladium, nickel, iron, cobalt, chromium oxide or molybdenum oxide. The catalyst base may be prepared by impregnating the amphoteric oxide with a solution of a compound which on heating decomposes to an oxide of iron, cobalt or nickel, e.g. the nitrate formate or acetate, followed by roasting at 700-1000 DEG C. for 1-10 hours. Preferably the base should contain 1-50% of nickel, cobalt or iron.  Alumina is preferably treated as a gel prepared by hydrolysis of aluminium isopropoxide and peptised with acetic acid; this may be stirred with an aqueous solution of the catalyst compound, dried at 140 DEG C. and then roasted.  Suitable acids for the extraction are sulphuric, hydrochloric, hydrofluoric, nitric or phosphoric; preferably an aqueous solution of less than 50% by volume concentration is used, at temperatures of 90-110 DEG C. for 15-30 minutes using two volumes of the acid or aqueous acid per volume of roasted material.  If the acid contains a radical having an adverse effect on catalytic activity, water washing is used to reduce the content of the acid radical to below a point at which the adverse effect is a material consideration.  The further catalyst may be added by impregnation in the normal way followed by roasting at 350-650 DEG C. for 1-10 hours, e.g. using aqueous solutions of tetrammine - platinous chloride, chromium nitrate, ammonium molybdate or the nitrate, formate or acetate of nickel, cobalt or iron according to the desired catalyst. Preferably the catalyst contains 1-30% of a metal so deposited. Reduction by hydrogen at 330-600 DEG C. for 2-48 hours may follow. Both the catalyst base and the complex catalyst are useful in hydrocarbon conversion processes, e.g. the base is cracking or polymerization and the complex catalyst in cracking, polymerization, dealkylating alkyl aromatics and hydrogenation.  Specifications 844,242 and 844,243 are referred to.