Abstract: A method is provided for putting a fresh bed of solid phosphoric acid catalyst into service to catalyze a hydrocarbon conversion process. The method involves establishing hydrocarbon conversion conditions of temperature and pressure in the catalyst bed while it is immersed in a hydrocarbon liquid which is substantially free of water and compounds which can yield water upon contact with the catalyst. Thereafter, the catalyst bed is used to catalyze the conversion of a hydrocarbon feedstock which contains a minor amount of a hydrating agent which is effective to provide a desired level of catalyst hydration. The method permits the catalyst to be rapidly brought to an optimum level of activity for the specific hydrocarbon conversion process.

Abstract: A method is provided for regenerating a fixed bed of olefin polymerization catalyst which can be performed without taking the catalyst bed out of service. The method involves the use of two different olefin-containing feedstocks, wherein the first feedstock is a conventional olefin-containing feedstock which contains little if any content of aromatic compounds. The second feedstock contains a significant concentration of aromatic compounds. In the practice of the invention, the second feedstock is substituted for the first feedstock whenever catalyst regeneration is deemed appropriate, and the flow of the second feedstock to the catalyst bed is continued for a period of time which is effective to at least partially regenerate the catalyst.

Abstract: A method is provided which can be used to quickly and easily take a fixed-bed of solid acid olefin polymerization catalyst out of service without causing any significant catalyst deactivation. The method involves substituting a substantially olefin-free hydrocarbon fluid for at least a portion of the olefin-containing feedstock to the polymerization process, wherein the substantially olefin-free hydrocarbon fluid boils within the range from about 20.degree. to about 250.degree. C. and contains at least about 5 vol. % aromatics.