The Industrial Application Of Environment-friendly Titanium PET Catalyst

Polyester production capacity of China leads the world.However,the technology and catalyst of polyester production in our country are mainly imported from abroad,without the intellectual property rights.At present,the antimony catalyst is widely used in the production of polyester domestic and international.Although the products quality made by the antimony catalyst is good,but antimony is heavy metal element,which is bad for the environment.The titanium catalyst is the research hot topic of polyester catalyst in recent years.Therefore,research and development of the titanium catalyst and its successful industrial application will make the Chinese polyester industry at a favorable position in the international competition.In this paper,the performance of the environment-friendly new titanium catalyst was investigated by combining laboratory experiments with industrial applications.In the laboratory,the process of direct esterification is used to simulate industrial production using the process route of the pure terephthalic acid(PTA)and ethylene glycol(EG).Through the orthogonal experiments,titanium catalyst performance was investigated under different amount of catalyst,temperature,pressure,etc,at the same time,polyester products made by new titanium catalyst were compared with that made by antimony catalyst(ethylene glycol antimony).It also was carried out the polyester synthesis experiment on 5,000 tons/year intermittent plant and 100,000 tons/year continuous plant.The experiment results showed that:1)The catalytic activity of the new titanium system is more than 20 times that of the antimony catalyst in the laboratory.Pressure at 0.3 MPa and temperature at 235?for esterification is more appropriate.When the vacuum is 30 Pa and temperature at 280? for polymerization,the activity of catalyst is better.2)On the 5,000 tons/year polyester intermittent plant,the feed ratio between PTA and EG is 1:1.2 ~ 1:1.4,which is more reasonable.After adding blue agent,the product color b has improved significantly.The addition quantity of trimethyl phosphate(TMP)is appropriate 80 ?g/g.3)On the 100,000 tons/year polyester continuous plant,for the system load changes,the new titanium catalyst has certainly reduced polymerization system load,the pre-polymerization 2 kettle agitator reduced 0.1 ~ 0.2 RPM and final polymerization kettle 0.15 ~ 0.2 RPM,reaction temperature reduced 2 ~ 3?.At the same time,the reaction time was shortened.For the main quality performance,the polyester products made by the new titanium catalyst in color,end carboxyl content and diethylene glycol are reaching or higher than which was made by the antimony catalyst.The product quality specifications met the requirements of the high-grade product.In one word,the application of the new environmentally friendly titanium catalyst in industrial production was successful.