CO2 content during catalyst reduction
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During the heating and reduction process, does the CO2 that is produced in the catalyst need to be removed promptly? Is it harmful if CO2 remains in the system and accumulates to around 30%? CU ZN AL catalysts contain about 8% minerals, which undergo thermal decomposition to produce CO2. Since there is H2 in the system, people are reluctant to remove this gas, resulting in more CO2 accumulating over time. By the time water is discharged, a small amount of methanol is already present. May I ask everyone: does CO2 need to be removed during the reduction process?
Since the catalyst contains carbonates, these decompose to produce CO2 during the heating and reduction process. During the hydrogenation stage, this CO2 must be removed from the system through venting after the tower, in order to prevent it from reacting with hydrogen at around 190 degrees Celsius and forming harmful substances such as paraffins.
The concern is that high carbon dioxide concentrations lead to the formation of basic copper carbonate, and there is a continuous reversible formation and decomposition with carbon dioxide, which results in a decrease in the catalyst’s activity and strength; such effects are serious.
It is absolutely harmful; when reducing copper-based methanol catalysts, the lower the carbon dioxide level, the better. High levels of carbon dioxide cause the formation of paraffins while hydrogen is being consumed, and these paraffins adhere to the surface of the catalyst, preventing complete reduction. At very high levels, they react with the active copper component to form basic copper carbonate, thereby reducing the amount of this active component and lowering the catalyst’s activity
The produced paraffin can definitely be taken out.
Carbon dioxide should preferably not exceed 10%, and it should be replaced with a large amount of nitrogen.
Today, the people from the manufacturer said that with high CO2 levels, zinc carbonate may be formed; basically, all active CuZn compounds get degraded
The formation of paraffin is not that scary; what’s concerning is the formation of basic copper carbonate. Additionally, high levels of CO2 can also slow down the reduction rate of the catalyst, which is unfavorable for its reduction.
The concern is that carbon dioxide reacts with zinc oxide, affecting the strength of the catalyst
Our synthetic catalyst was reduced using pure hydrogen, with a value of less than 1 at most, which is very good.
Basic copper carbonate will not be formed. I asked the engineers at Nanhua Institute; it is zinc that undergoes the main reaction