Selective poisoning of aromatization catalysts to increase catalyst activity and selectivity

A reforming method comprising:

• (a) providing a radial flow reactor comprising a catalyst bed, the catalyst bed comprising an outer reforming zone and an inner reforming zone;
• wherein:
• the outer reforming zone comprises a spent first aromatization catalyst comprising a first transition metal and a first catalyst support;
• and
• the inner reforming zone comprises a second aromatization catalyst comprising a second transition metal and a second catalyst support;
• (b) introducing a catalyst poisoning agent into the radial flow reactor and contacting at least a portion of the spent first aromatization catalyst to form a poisoned aromatization catalyst in the outer reforming zone;
• and
• (c) introducing a hydrocarbon feed into the radial flow reactor comprising the catalyst bed, and contacting the hydrocarbon feed with the catalyst bed under reforming conditions to produce an aromatic product;
• wherein:
• the spent first aromatization catalyst comprises from about 1 wt. % to about 10 wt. % carbon;
• the poisoned aromatization catalyst has an aromatics yield of less than 10 wt. %;
• and
• the catalyst poisoning agent comprises a heavy hydrocarbon, a sulfur-containing compound, a phosphorus-containing compound, an oxygen-containing compound, a bromine-containing compound, an iodine-containing compound, an organometallic lead compound, an organometallic arsenic compound, or any combination thereof.

A reforming method comprising:

• (A) introducing a first hydrocarbon feed into a radial flow reactor comprising a catalyst bed, and contacting the first hydrocarbon feed with the catalyst bed under first reforming conditions to produce a first aromatic product;
• wherein:
• the catalyst bed comprises an outer reforming zone and an inner reforming zone;
• the outer reforming zone comprises a first aromatization catalyst comprising a first transition metal and a first catalyst support;
• and
• the inner reforming zone comprises a second aromatization catalyst comprising a second transition metal and a second catalyst support;
• (B) performing step (A) for a time period sufficient to form a spent first aromatization catalyst in the outer reforming zone;
• (C) introducing a catalyst poisoning agent into the radial flow reactor and contacting at least a portion of the spent first aromatization catalyst to form a poisoned aromatization catalyst in the outer reforming zone;
• and
• (D) introducing a second hydrocarbon feed into the radial flow reactor comprising the catalyst bed, and contacting the second hydrocarbon feed with the catalyst bed under second reforming conditions to produce a second aromatic product;
• wherein:
• the spent first aromatization catalyst comprises from about 1 wt. % to about 10 wt. % carbon;
• the poisoned aromatization catalyst has an aromatics yield of less than 10 wt. %;
• the catalyst poisoning agent comprises a heavy hydrocarbon, a sulfur-containing compound, a phosphorus-containing compound, an oxygen-containing compound, a bromine-containing compound, an iodine-containing compound, an organometallic lead compound, an organometallic arsenic compound, or any combination thereof;
• an aromatics yield of the second aromatic product in step (D) is greater than a yield of the first aromatic product produced after step (B) and before step (C);
• and
• an aromatics selectivity of the second aromatic product in step (D) is greater than an aromatics selectivity of the first aromatic product produced after step (B) and before step (C).