Ethylene to ethylbenzene technology refers to the reaction of ethylene and benzene alkylation to form ethylbenzene under the action of catalyst
99% of ethylbenzene is dehydrogenated to styrene, styrene is an important monomer of synthetic resin , ion-exchange resin and synthetic rubber. It can be used to produce styrofoam, polystyrene and styrene butadiene rubber; it is also used to copolymerize with other monomers to make engineering plastics of various uses; it is also one of the raw materials for producing ion-exchange resin and medicine. In addition, styrene can also be used in pharmaceutical, dyes, pesticides and mineral processing industries.
1， Adaptable raw material
Ethylene can be derived from pure ethylene or refinery catalyzed dry gas.
2， Physicochemical properties of catalysts
Item | Index |
Appearance | White - grey ball |
Diameter，mm | 2.5-3.0 |
Bulk density，kg/L | 0.5-0.6 |
Intensity | ≥30 |
BET，m2/g | >350 |
3，Process conditions
Item | Value |
Alkene weight SV，hr-1 | 0.25-0.30 |
Benzene/alkene ，mol/mol | 5-6 |
Sprinkle density，m3/m2.hr over | 16 |
Pressure，MPa | 2.5 |
Temperature，℃ | 160-180 |
4，Technical flow diagram
5， Process characteristics
The raw material purification system is added to improve the adaptability of the process to raw materials; adopt liquid phase reaction, the reaction conditions were mild, the ethylbenzene selectivity was higher than 98%, and the xylene content was no more than 50PPM; adopt innovative catalytic absorption, distillation process, different from ordinary catalytic distillation process, allow the backmixing,
at a certain ratio of benzene to benzene, the spray density can be distilled at the bottom of the tower, reflux and circulation are controlled together, in this way, the reaction temperature can satisfy the larger spray density at a lower temperature, which is beneficial to prolong the life of the catalyst.