The adsorbent has absorbed 10 kg of methanol, and nitrogen is planned to be used for purging. What conditions should be controlled to use the least amount of nitrogen possible...
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The adsorbent has absorbed 10 kg of methanol, and nitrogen is to be used for purging. What conditions need to be controlled in order to remove as much methanol as possible using the least amount of nitrogen? Some people suggest raising the temperature; but what if the temperature remains constant at, for example, 60 degrees Celsius? The nitrogen gas exiting the purging process is cooled to around 10 degrees Celsius using a condenser. What needs to be considered here is the situation inside the adsorption tower during nitrogen purging. I would appreciate some guidance
But can increasing the temperature really reduce nitrogen consumption? As the temperature increases, the nitrogen partial pressure also rises. What other ways are there to increase pressure?
Raising the nitrogen temperature is intended to increase the temperature of the adsorbent and thereby improve the desorption efficiency of methanol
So, what should be done in this case, and how can nitrogen consumption be minimized? ?
1. Increase the temperature of the purging nitrogen gas. 2. Circulating purge.
It is feasible to increase the temperature of the purge nitrogen, but implementing circulation for purging may be very difficult, as nitrogen is usually provided as part of utility services and there are no circulation devices available. Moreover, after nitrogen is used for purging, methanol must be condensed and removed; before it can be reused for purging, it needs to be heated again, and the energy required for heating is considerable
Nitrogen is so cheap that there’s no need to save on it; heating helps with desorption. Operating at reduced pressures, or even under negative pressure, also facilitates desorption
Then I would like to ask what is an appropriate amount of nitrogen to introduce? How should the optimal value for this parameter be determined?
Then I would like to ask what is an appropriate amount of nitrogen to introduce? How should the optimal value for this parameter be determined?
But as the temperature increases, the partial pressure of nitrogen also rises; with constant pressure, the gas essentially expands, so can more ethanol be contained? Can raising the temperature in this way remove more ethanol?
Firstly, the amount of nitrogen gas introduced cannot be determined; it needs to be calculated based on the desorption characteristics of the adsorbent. Secondly, it is not the nitrogen gas that carries away the methanol – rather, it is the adsorbent that releases the methanol, with the nitrogen gas displacing it