Performance Characteristics and Applications   
The EH-4 propylene specific COS hydrolysis catalyst is a new and efficient COS hydrolysis catalyst developed by Hubei Chemical Research Institute based on T504 hydrolysis catalyst, EH-2 and EH-3 medium temperature sulfur tolerant catalysts. It is mainly used for the hydrolysis removal of COS in raw propylene and is used in conjunction with EZ-2 and other refined desulfurizers to achieve a total sulfur content of less than 0.1 times in purified propylene for export; 10-6, achieving the goal of fine desulfurization, can make the total sulfur (COS+H₂S)≤ 0.1× 10-6, where COS<; 0.02× 10-6, effectively protect the high-efficiency polypropylene catalyst in the later section. Compared with ordinary hydrolysis catalysts, it has the following characteristics:
1. Good catalytic activity, high COS removal accuracy, outlet COS content≤ 0.02× 10-6.
2. High liquid velocity can be used under conditions of 6-15 h-1.
3. It can be used in a wide temperature range of 10-100 ℃.

Two reaction principle
  Under the action of a catalyst, COS or CS₂reacts with trace amounts of water remaining in the raw material propylene to generate CO₂and H₂S. The generated H₂S is then removed using precision desulfurizers such as EZ-2, achieving the goal of precision desulfurization. The reaction equation is:
COS＋H₂O====H₂S＋CO₂      Δ H=－35.5KJ/mol

Three main physical and chemical properties and quality indicators
Table 1  Main physicochemical properties of EH-4 propylene specific COS hydrolysis catalyst

Table 2    Main quality indicators of EH-4 propylene specific COS hydrolysis catalyst

Four normal operation and usage conditions
1. Liquid airspeed: 3-15h-1
2. Temperature: 10-100 ℃
3. Pressure: Normal pressure~15.0Mpa
4. Temperament requirements: imported H2S≤ 10× 10-6， COS≤ 10× 10-6

Five measuring instruments:
HC-4 propylene specific trace sulfur analyzer, with a minimum detection limit of COS<; 0.02× 10-6， H₂S< 0.1× 10-6.