[jimdvfd]

I know that Ammonia and Acetaldehyde react to form Ammonia  Acetaldehyde Trimer.  Will this reaction occur if both the Ammonia and Acetaldehyde are in a water solution?  I have a wet scrubber on a ethanol fermentation tank.  The scrubber removes Ethanol and Acetaldehyde vapor that is emitted with the CO2 Gas.  The efficiency of the acetaldehyde is poor because the boiling point of acetaldehyde is 68F which is close to the water temperature.  I would like to add Ammonia to react with Acetaldehyde to improve efficiency of removal.
Assuming this works the water from the scrubber is used to make the next batch of ethanol. The mash is heated to 185F. Will the Ammonia and Acetaldehyde Trimer in solution be thermally stable at 185F?

[Honclbrif]

Water is a byproduct of the reaction between ammonia and acetaldehyde, so Le Chatelier's principle would likely disfavor the reaction in aqueous media. You might be able to use an acidic solution in the scrubber to hydrate the aldehyde to the geminal diol which would be a lot less volatile than the parent compound.

However, I'm still not totally sure what you are you trying to here. Do you want to recover the acetaldehyde for reuse, or remove it completely? As long as you are not recirculating the waste gas from the scrubber back into the fermentation vessel the acetaldehyde should be carried away completely.

[jimdvfd]

Acetaldehyde is a hazardous air pollutant.  It is there in low concentrations and I need to remove as much as possible.

[discodermolide]

Acetaldehyde is a hazardous air pollutant.  It is there in low concentrations and I need to remove as much as possible.

Scrub  the exhaust through an acidic bisulphite solution then you will make the bisulphite adduct. Or scrub the gasses through an oxidant. Watch the temp of the scrubber does not get too hot!

[jimdvfd]

There is a lot of ethanol that is recovered so I can't use anything that will distroy the ethanol. Presently we use ammonium bisulfite. It work good.  Its is expensive and the bisulfite does cause problems in the distillation process. In the past we used sodium bisulfite the sodium causes fermentation problems.