×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Anhydrous Ammonia Venting
4

Anhydrous Ammonia Venting

Anhydrous Ammonia Venting

(OP)
We are installing an anhydrous ammonia tank in our coal burning power plant to inject for flue gas conditioning.  My question has to do with the loading by truck of the product.  The tank will be at 600 kPag (14°C) to 815 kPag (22°C), so when we fill the tank, the truck driver will equalize the pressure between holding tank and truck tank and then fill.  After he is done, there will be approximately 8 kg of liquid in the fill line, which will then need to be vented.  I have heard of putting the hose into a bucket of water and allowing the ammonia to flash in there, reducing vapor exposure.  Does anyone have experience with this?  How do you determine the amount of water required?  

RE: Anhydrous Ammonia Venting

I once used a stainless steel portafeed (4'x4'x4') that was 75% filled with 10% NaOH solution.
The portafeed was located about 10-feet from the ammonia truck station.
Small diameter (1/4") stainless steel tubing from vapor hose and liquid hose bleeds were inserted below the liquid level.
When ammonia odor was detected (about once a year), a fork lift transported the portafeed to an ecology sewer.
The contents were dumped and replaced with fresh solution.

RE: Anhydrous Ammonia Venting

you might consider venting the connection to your end user which i assume will be somewhere on the vent gas system.  this will cause autorefrigeration but with a bit of encouragement, the liquid would boil off in just a few minutes.  then you would have very little vapor to vent off for the final disconnect.

i doubt you want to bother with the money to install a recovery compressor to compress it and return it to your storage.

i am not sure that NaOH would be a good thing.  NH3 reacts with water to make NH4OH and is itself a high pH, basic solution.  we used to use NaOH to drive NH3 from a wastewater stream.

it would seem that you would be better with an acidic solution.

RE: Anhydrous Ammonia Venting

Ammonia is highly soluble in water. You have to be careful that you do not suck water up the line into the ammonia hose. And caustic would reduce solubility of ammonia in water as Ben says.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources