Where do CO and CO2 in propylene come from?
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As the title suggests: Where do CO and CO2 come from in propylene? In previous propylene samples, the levels of these two substances were below 10 ppm; however, recently their levels have increased – CO at 12.9 ppm and CO2 at 54.7 ppm. Did these substances come from the reaction process? How can this be adjusted?
The absorption stability, and especially the desorption effect, need to be adjusted, right?
COS hydrolysis can produce CO2
1. Sampling issue. 2. I’m not sure what form your two devices are in; also, check the CO and CO2 content in your propylene, as well as the condition of the dry gas, and pay attention to the nitrogen content.
It is likely due to the hydrolysis of carbonyl sulfide. Let’s check if there have been any recent changes; there is a relatively high amount of COS in the non-condensable gases from reformation processes, which makes hydrolysis more likely to occur. As for CO, it is probably related to the removal of dry gas components, since the gas separation process generally does not involve any reduction steps.
The possibility of wear and damage in the stripping section is very low. Firstly, if there is a leak in the catalyst fluidization, the catalyst will carry some of the leaked flue gas with it as it moves downward. Secondly, if the amount of leakage is large, there should be problems with the catalyst’s fluidization state, resulting in significant changes in density； Theoretically, it can be determined from the components in the dry gas, but in practice it’s still minimal!
1. Increase the emission volume of the vapor from the deethanization tower top. 2. A small amount of vapor from the propylene reflux tank can be emitted; such emitted gas can be recovered by the air compressor
It’s likely that this happens as the regenerated catalyst circulates through, but these two components should be included in the dry gas; there should be very little of them in the liquefied gas! If it’s brought in from this side, consider aspects such as the efficiency of separation, excessive absorption, and the control of pressure and temperature at the top of the stabilizer; the key issue is likely related to separation
How do we make adjustments? Currently, we adjust the analysis results by looking at the carbon dioxide content in liquefied gas