Design issues for molecular sieve dehydration towers?
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Design issues for molecular sieve dehydration towers? 4A molecular sieve was used to remove water from 95% ethanol, with a total feed volume of 105 kilograms. Design calculations were carried out in accordance with the methods specified in the \"Natural Gas Dehydration Design Code\": gas-phase feed, operating pressure of 3.5 kilograms, and operating temperature of 170 degrees Celsius. However, the calculations showed that the tower diameter would be less than 150 millimeters, while the tower height would need to be 51 meters. It’s clearly wrong, but I don’t know what the problem is. Could someone experienced give me some advice?
This post was last edited by goldliyang on 2016-7-11 at 11:56. How were these figures calculated? They are clearly incorrect. Also, why use molecular sieves?
{:3_47:} Then you can feed from the bottom, haha. . . I don’t understand things like calculations. . .
The alcohol dehydration process is now well-developed, so the calculation methods used for natural gas dehydration are not very useful. Don’t rigidly apply formulas, otherwise the installation will definitely fail: L
So how do I determine the process flow, and how do I calculate the size of the dehydration tower? The original poster is an expert; could you share the materials? Thank you!
Alcohol dehydration: A low-pressure gaseous feed is used, with molecular sieves absorbing water; gaseous ethanol is not absorbed. Once saturation occurs, the material is heated to over 200 degrees to regenerate and recover the water. The gaseous alcohol is then cooled through heat exchange with liquid alcohol to be liquefied. If you need a design, I can prepare one for you
The more water can be adsorbed by the adsorbent at reduced pressure and low temperature, but as the temperature and pressure increase, the adsorbent regenerates the water. For large-scale continuous processes, the process on the 7th floor can be used. For processes involving small quantities, it is possible to avoid heating 95% ethanol to steam, thereby reducing energy consumption; instead, the 95% ethanol can be used at room temperature and allowed to soak in the absorption tower for about 2 hours, after which sampling can be conducted to verify that the results are satisfactory. The absorption tower requires a jacket and internal heating coils for the regeneration of the adsorbent; the liquid resulting from this regeneration is then re-distilled to be used as raw material for the production of 95% ethanol.
Moreover, vacuum is required during regeneration, which allows the regeneration temperature to be much lower