Process of producing para-xylene by alkylation of benzene and/or toluene including treatment of an alkylating agent to remove metal salts

A process for producing para-xylene, the process comprising:

• (a) separating a feedstock comprising an alkylating agent and a metal salt into at least an alkylating agent-rich vapor stream and a metal salt-enriched liquid blowdown comprising alkylating agent and metal salt, wherein the alkylating agent-rich vapor stream comprises less than 0.1 wppm metal salt;
• (b) reacting at least a portion of the alkylating agent-rich vapor stream with benzene and/or toluene in the presence of an aluminosilicate zeolite catalyst under alkylation conditions to yield para-xylene, wherein the aluminosilicate zeolite catalyst comprises a porous crystalline material having a Diffusion Parameter for 2,2 dimethylbutane of about 0.1-15 sec-1 when measured at a temperature of 120° C. and a 2,2 dimethylbutane pressure of 60 torr (8 kPa), and wherein the alkylation conditions comprise a temperature from 350 to 700° C., a pressure from 100 to 7000 kPa, and a weight hourly space velocity from 0.5 to 1000 hr−1,
• (c) sorbing at least a portion of the metal salt from the metal salt-enriched liquid blowdown so as to form an alkylating agent-rich liquid stream and a first metal salt-rich liquid effluent;
• (d) separating the alkylating agent-rich liquid steam into an additional alkylating agent-rich vapor stream and a second metal salt-rich liquid effluent;
• and
• (e) flowing a sidestream produced from the separating in (d) to the reacting in (b), wherein the sidestream comprises steam.