How long can the catalyst for MTBE last?
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The catalyst used is D006 resin. The plant has been in operation for three years, and now it has been found that the purity of MTBE does not reach 98.5%. I would like to ask how long a catalyst can generally be used. My design calls for a production capacity of 50,000 tons; although the plant has been operating for three years, it has not been running at full capacity, with the load remaining around 40% throughout. Experts, has my catalyst become inactive? How can one determine whether a catalyst has become inactive through analytical testing? Thank you. This post was last edited by psw1420 on 2009-3-24 10:08.]
Judging from the isobutylene conversion rate, in the case of a fixed-bed expansion process, if the conversion rate is below 80%, it can be preliminarily concluded that the catalyst has become deactivated.
By analyzing the content of isobutylene in the product, under the same conditions and temperature, an increasing trend is observed, which indicates a decline in activity. In our factory, the catalysts can operate at full capacity for about two years; the level of activity depends not only on the quality of the catalyst but also on the operating conditions. Three years is sufficient for your case.
98.5% is really excellent; sometimes we only require 85% for MTBE+MSBE. However, we are a private enterprise with limited resources. Our criterion for determining catalyst performance is the temperature of the catalyst bed – if the feed temperature is 40 degrees Celsius and the bed temperature doesn’t reach above 60 degrees Celsius, it’s considered inactive. There are 3 layers of catalysts, and once the top layer becomes inactive, it can be replaced entirely. We don’t have the necessary resources as a private enterprise: L :L
Everyone gave great answers; you can increase the reactor inlet temperature a bit to compensate for the effects of catalyst deactivation!
The lifespan of the catalyst depends on the type of C4 you use. If it is refinery C4, its lifespan is very short, generally not exceeding 1 year; whereas if it is butadiene extract C4 followed by washing, its lifespan can reach over 3 years. The reason is that the content of heavy metals and the like in the raffinate C4 is low. I use raffinate C4+ washed by Yangzi Petrochemical here; the catalyst is generally replaced every 3 years.
We don’t have water washing here; it’s crude oil C4, and the catalyst has been in use for two years – the upper and middle sections of the reactor have become inactive.
We determine this based on the bed temperature and the conversion rate of isobutylene. Additionally, the service life of the catalyst is also related to the composition of your raw materials and the control of process temperature.
Three years is really impressive; we replace the resin in the reactor once a year, using our innovative online replacement technology! Only the reactor and catalytic distillation column need to be replaced every three years!
The service life of a catalyst cannot be determined by the absolute amount of time it is used; instead, it should be assessed based on the total amount of MTBE produced by it. For example, a catalyst is considered to be effective if it can produce around 100,000 tons of MTBE before needing to be replaced. As for the usage time, it is highly dependent on the raw material; for refinery C4, more than a year is already considered good. Later on, it’s better to mention the reaction pressure first, and then the preheating temperature
A new catalyst should function properly for 3 years; during normal operation, it is important to strictly control the temperature in the middle section, keeping it below 85 degrees as much as possible； If the purity is found to be low after using it for some time, try increasing the inlet temperature; but be sure to check whether there is any change in color after the reaction ；