[Q&A Question 206] 11.12.2016
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【Q&A Question 206】November 12, 2016: Why, during the pre-sulfurization of a catalyst, before hydrogen sulfide penetrates, cannot the bed temperature exceed 230°C? The answer key will be available after responding; scoring is based on answering the key points. During the pre-sulfurization process, before hydrogen sulfide penetrates the catalyst, if the temperature is above 230°C, the catalyst in its oxidized state will be reduced to its metallic form, thereby reducing the catalyst’s activity and affecting the efficiency of pre-sulfurization. 2016 Q&A Summary Post (updated as of November~~~~) Seeking sponsors for the “2016 HaiChuan Top 10 Members Selection Contest” http://bbs.hcbbs.com/thread-1628108-1-1.html (Source: HaiChuan Chemical Forum)
Because during the catalyst presulfidization process, before hydrogen sulfide penetrates the catalyst, if the temperature is above 230°C, the catalyst in its oxidized state will be reduced to metallic form by hydrogen, thereby reducing the catalyst’s activity and affecting the sulfidization process.
The catalyst is in a metallic oxidation state; at temperatures above 230, it reacts with hydrogen through reduction and loses its activity
This is because during the catalyst pre-sulfidization process, before hydrogen sulfide penetrates the catalyst, if the temperature is above 230°C, the catalyst in its oxidized state will be reduced to metallic form by hydrogen, thereby reducing the catalyst’s activity and affecting the sulfidization process.
I believe that above this temperature, the already vulcanized catalyst sees an increase in its activity, causing it to participate in other reactions and leading to uneven vulcanization.
Above 230, it can easily lead to overheating; sulfidation occurs too quickly and there is too much reaction heat, so a constant temperature is essential
During the pre-sulfurization process, before hydrogen sulfide penetrates the catalyst, if the temperature is above 230°C, the catalyst in its oxidized state will be reduced to its metallic form, thereby reducing the catalyst’s activity and affecting the efficiency of pre-sulfurization.
If the temperature is high, the catalyst in its oxidized state will be reduced to metallic monomers by hydrogen, thereby reducing the catalyst’s activity and affecting its sulfidation efficiency