Will rapid cooling with hydrogen increase the reaction depth and raise the temperature rise?
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As the title suggests: 1. When the reaction materials in the reactor bed are not at a saturated state, the introduction of cold hydrogen increases the hydrogen partial pressure, bringing it to a saturated level; this also increases the diffusion rate. In such a situation, does the reaction necessarily intensify, resulting in more heat release and an increase in temperature? 2. Can the state of the reaction materials within the bed be determined based on specific signs during the production process?
Secondly, as the reaction proceeds, the hydrogen partial pressure in each bed layer within the reactor is different; it decreases as one goes deeper. So cold hydrogen also won’t affect the hydrogen partial pressure
Cold hydrogen is mainly used for cooling; this temperature has a much greater impact on the reaction than the hydrogen partial pressure does, so the effect will not be significant
Thanks for the explanation! It’s still a bit unclear: as the reaction process continues to change, the hydrogen partial pressure keeps decreasing, and the severity of the reaction gradually increases. The reaction in the next bed layer is driven by a higher temperature rise; if an appropriate amount of cold hydrogen is added, this reduces the local temperature, but it also improves the reaction conditions (firstly, an increase in the hydrogen partial pressure will inevitably have a positive effect on the reaction) ； Secondly, as long as hydrogen is not in a supersaturated state, which certainly facilitates adsorption and diffusion on the catalyst surface, isn’t it also possible for this to increase the reaction depth?
The temperature of the rapidly cooled hydrogen is low, so the temperature it induces will not cause the reactor to heat up
The hydrogen inside the reactor is already in excess, far exceeding the amount required for the reaction. The amount of cold hydrogen added does not substantially change the circulation volume; therefore, it has no significant effect on the degree of reaction. The role of cold hydrogen is mainly to ensure safety, as well as to control the temperature rise in the bed and reduce coking and side reactions
Thank you! At excessive levels, it should not only be able to carry away the reaction heat but also reduce the opportunities for the reactants to come into contact with the active centers of the catalyst, thereby suppressing the reaction.
It’s to reduce the residence time, right:lol
The core is to increase the reaction depth. Pressure, temperature, purity, catalyst? Can a catalyst increase depth? Think about each one individually and you’ll find the answer
When hydrogen is introduced, the cooling is not solely due to the low temperature of the hydrogen itself; rather, it is mainly caused by a decrease in the partial pressure of light hydrocarbons, with the endothermic vaporization process contributing to the cooling as well