What is vulcanization, and why is it necessary to carry out vulcanization before the equipment is put into operation?
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What is vulcanization, and why is it necessary to carry out vulcanization before the equipment is put into operation?
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Sulfidation involves reacting the main component of the catalyst, which is an oxide, with H2S to convert it into a sulfide. Since oxides do not have catalytic activity, they need to be sulfidated in order to become active. Sulfidation can be carried out in two ways: online sulfidation and pre-sulfidation
In the sulfur-resistant shift catalysts provided by catalyst manufacturers, cobalt and molybdenum exist in the form of oxides (CoO and MoO3). The catalytic activity of these oxides for the shift reaction is very low; they only become catalytically active after being sulfided to form MoS2. Similarly, CoO, which acts as a co-catalyst, must also be converted into a sulfide before it can significantly enhance the catalyst’s activity； Furthermore, sulfidation can also prevent the oxides of cobalt and molybdenum from being reduced to their metallic states, thereby promoting methanation reactions. This leads to a significant temperature rise in the catalyst bed, resulting in sintering and damage to the catalyst; therefore, sulfidation must be carried out before using the catalyst.