David:<br>
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I don't have an answer to your problem, but maybe I can help you somewhat. &nbsp;First of all, assuming that your MIBK is methyl isobutyl ketone, let's list the boiling points involved:<br>
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Water: atmospheric boiling point is 212 deg F<br>
Ammonia: atmospheric boiling point is -28 deg F<br>
MIBK: atmospheric boiling point is 242 deg F<br>
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Thus, if no MIBK were present, your 40 deg F cooling water would certainly condense the water vapor in the stripper overhead ... but it would not condense the ammonia. &nbsp;However, since ammonia is VERY soluble in water, it would dissolve in the condensed water. &nbsp;Therefore, that is very probably the mechanism that took place in your previous pilot plant runs (i.e., the water was condensed and the ammonia was dissolved in the water).<br>
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Now with MIBK present, it was definitely condensed along with the water. &nbsp;And since MBIK is moderately soluble in water and you only have small amounts of it present in the feed (i.e., 330 ppm which is 0.033 weight percent), it probably dissolves in the water. &nbsp;And somehow or other, for a reason I cannot explain, it interferes with the ammonia dissolving in the water.<br>
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You might try two stages of condensing with a with a vapor-liquid separation vessel between the two stage of condensing. &nbsp;Perhaps, if all of the MIBK is condensed at a higher temperature of about say 230 deg F and removed as a liquid, then the second stage condenser could condense the water and dissolve the ammonia in the condensed water.<br>
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Milton Beychok<br>
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