PROCESS FOR THE RECOVERY OF CRUDE TEREPHTHALIC ACID (CTA)

摘要

The present invention relates to a process for the preparation of crude terephthalic acid which comprises first introducing a slurry containing crystallized terephthalic acid with impurities in an aliphatic carboxylic acid mother liquor into a rotary filter comprising a case and a rotating drum, wherein the rotating drum is subjected to a uniform pressure differential over the entire drum, and the inside of the drum is at a pressure approximately equal to atmospheric pressure or greater, then filtering said slurry; and finally collecting at least some of the solid portion. Other aspects of the invention include continuously adding the original slurry to the rotary filter and washing the solid portion with additional aliphatic carboxylic acid, water or a combination of the two. The solid portion can then be transferred to a reslurry tank which is at the same pressure as the pressure at the point where the solid portion was collected. The present invention also relates to a process for the preparation of crude terephthalic acid which comprises first introducing a slurry containing crystallized terephthalic acid with impurities in an aliphatic carboxylic acid mother liquor into a rotary filter comprising a case and a rotating drum, wherein the rotating drum is subjected to a uniform pressure differential over the entire drum, then filtering said slurry, washing the solid portion with water; and finally collecting at least some of the solid portion. Other aspects of the invention include continuously adding the original slurry to the rotary filter and additional washing with the aliphatic carboxylic acid mother liquor. The inside of the drum can be less than, greater than or approximately equal to atmospheric pressure. The solid portion can then be transferred to a reslurry tank which is at the same pressure as the pressure at the point where the solid portion was collected.