PTA Unit in Yanshan Petrochemical
            Co Ltd Shifted to Isophthalic Acid
The former PTA unit in Yanshan Petrochemical Co., Ltd.  had
a small production scale and many defects in  process  and
equipment and  can  no  longer  produce  PTA  with  market
competitiveness. Polyester Business Research Department of
Yanshan Petrochemical Co., Ltd. started the research of  m
-phthalic acid production technology in 1996 and made  many
pilot tests and commercial  production  tests.   Technical
renovation was conducted to the former PTA unit  in  1998.
  The  renovation  was  completed  and  the  production  of
isophthalic acid was started in August 1999. The unit  has
a capacity of 30 000 t/a and is  the  only  domestic  unit
which can produce superior quality m-phthalic  acid.   The
capacity will be further expanded to 45 000 - 50 000 t/a.