Discussion on the heating method for methanol catalysts
Thread Content
Issues with heating methanol catalysts: 1. Regarding the problem of heating methanol catalysts, catalysts in an oxidized state need to be heated for reduction； 2. The catalyst that has been reduced (under nitrogen protection) needs to be heated to the specified temperature ； 3. The methods of heating include electric heating, steam heating, and even gas heating.
Regarding the steam heating method for raising temperature: 1. Forced circulation heating using a pump: In this method, steam enters the drum directly to heat the feed water. Common techniques include Casali, Anchun, etc. 2. Temperature elevation using a steam ejector: This method is very common and is used in all shell-and-tube reactors.
There are also some methanol processes where the synthesis system is equipped with a startup heater
All various methods of raising temperature are intended to ensure an effective temperature increase
Regarding the heating of the methanol reactor, when a steam injector is used, high-pressure steam passes through the injector, creating a negative pressure on the side that draws in boiler water; this mixture then enters the reactor, where it forms a loop to heat the gas and thereby achieve a gradual increase in temperature. The boiler water of the reactor enters the ejector
High-pressure steam passes through the ejector, creating negative pressure on the side to draw in boiler water; after mixing, it enters the reactor where a circulation loop is formed. The common approach is for the water exiting from the upper part of the reactor to flow into the side of the ejector, while the water exiting from the ejector flows into the lower part of the reactor, thus forming a loop. It has good heating performance.
High-pressure steam passes through the ejector, creating negative pressure on the side to draw in boiler water; after mixing, it enters the reactor where a circulation loop is formed. The common approach is for the water exiting from the upper part of the reactor to flow into the side of the ejector, while the water exiting from the ejector flows into the lower part of the reactor, thus forming a loop. It has good heating performance. Recently, I saw a method opposite to this one of water inlet: in that case, the water from the ejector enters the reactor from the top, while the water from the bottom enters the side of the ejector. Form a loop. Which of these two methods is better?
Currently, all methanol production processes on a multi-million-ton scale use steam injectors to drive the boiler water in order to heat the catalyst. The purpose of heating and reducing the catalyst in its oxidized state is to reduce it to an active state, thereby endowing it with the ability to synthesize methanol. Heating the catalyst in a nitrogen-sealed state involves raising the temperature to the activation temperature for the methanol synthesis reaction. The heating rates and control points for the two stages are different.
It’s the Venturi effect; it doesn’t really matter how it gets in