Little Domestic Production of TMA and PMDA
                             By Wei Ke
TMA and PMDA are important  raw  materials  in  the  organic  synthesis
industry and also basic raw materials for new chemical  materials  and
fine chemicals with high added value.
Nanjing Paint Plant and Harbin Petrochemical Plant  constructed  a  300
t/a TMA unit and a 250 t/a TMA unit respectively in the 80's, but  due
to various reasons normal production has never been made.  Wuxi  Xibei
Resin Plant of Jiangsu constructed a 500 t/a TMA  production  line  in
1990, but it was later shut down. A 500 t/a  TMA  production  line  in
Jiangsu Jiangyin Acetic Anhydride Plant started  production  in  1995.
The unit uses the process of liquid phase oxidation of acetic acid air
medium. The product is mainly supplied to  factories  in  Jiangsu  and
Shandong to produce heat-resistant plasticizers  and  polyester.   The
product is in short supply and the second phase 2  500  t/a  unit  has
started production.
The production of PMDA in China is still at the pilot test and research
stage. There are reports on the 15 t/a unit in Shanghai  Coking  Plant
using the alkylation process and the 50 t/a unit  in  Anshan  Chemical
Plant, but there is almost no commercial production in China.
Compared with advanced foreign countries, the  domestic  production  of
TMA has a considerable gap in both technology and capacity. TMA has  a
very small output and PMDA still has  no  production  in  China.   The
domestic market demand can not be satisfied and a great amount of  the
products have to be imported from abroad each year.
TMA and PMDA in China are mainly used in  electric  wires  and  cables,
coatings and polyimide. The demand is expected to have  a  big  margin
increase in future.