Method and apparatus for treating dehydrogenation catalysts

A method of regenerating and stabilizing the activity of a dehydrogenation catalyst, consisting essentially of iron oxide catalyst promoted with alkali metal, used in the catalytic dehydrogenation of an alkylaromatic hydrocarbon in a series of reactors containing said catalyst to obtain an alkenylaromatic hydrocarbon, said method comprising the steps of:

• adding to a feedstream consisting essentially of said alkylaromatic hydrocarbon reaction product from said reactors and steam an effective amount of an alkali metal compound equivalent to a continuous addition of about 0.01 to about 100 parts per million by weight of alkali metal compound relative to the weight of said feedstream, said effective amount being sufficient to maintain substantially constant levels of catalyst conversion and selectivity, to form a mixed reactant stream;
• and, directing said mixed stream into said reactor while continuing said catalytic conversion beyond an initial catalyst conditioning period of about 3-45 days.

A method of regenerating and stabilizing the activity of a catalyst consisting essentially of iron oxide catalyst promoted with alkali metal while continuing the catalytic conversion of synthesis gas to gasoline fraction hydrocarbons comprising the steps of:

• (a) forming a mixed reactant stream consisting essentially of said synthesis gas and an effective amount of an alkali metal compound equivalent to a continuous addition of about 0.01 to about 100 parts per million by weight of alkali metal compound relative to the weight of said reactant stream, said effective amount being sufficient to maintain high levels of conversion:
• and (b) bringing said mixed reactant stream into contact with said catalyst while continuing said catalytic conversion beyond an initial catalyst conditioning period.

A method of regenerating and stabilizing the activity of a catalyst consisting essentially of iron oxide catalyst promoted with alkali metal while continuing the catalytic dealkylation of an alkylaromatic hydrocarbon to obtain an aromatic hydrocarbon comprising the steps of:

• (a) forming a mixed reactant stream consisting essentially of said alkylaromatic hydrocarbon and an effective amount of an alkali metal compound equivalent to a continuous addition of about 0.01 to about 100 parts per million by weight of alkali metal compound relative to the weight of said reactant stream, said effective amount being sufficient to maintain high levels of conversion;
• and (b) bringing said mixed reactant stream into contact with said catalyst while continuing said catalytic conversion to said aromatic hydrocarbon beyond an initial catalyst conditioning period.

A method of regenerating and stabilizing the activity of a catalyst consisting essentially of iron oxide catalyst promoted with alkali metal while continuing the catalytic synthesis of ammonia from nitrogen and hydrogen comprising the steps of:

• (a) forming a mixed reactant stream consisting essentially of said nitrogen and hydrogen and an effective amount of an alkali metal compound equivalent to a continuous addition of about 0.01 to about 100 parts per million of weight of alkali metal compound relative to the weight of said reactant stream, said effective amount being sufficient to maintain high levels of conversion:
• and
• (b) bringing said mixed reactant stream into contact with said catalyst while continuing the catalytic conversion to ammonia beyond an initial conditioning period.