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gwapa
11-03-2014, 09:07 PM
Dear all
We are involved in a project to pipe all the discharge valve to a tank. The vessel should be able to diminish the impact of the ammonia discharge to the atmosphere


We thought to use a water spray and to bubble the ammonia in water. The issue is get rid of the water after it be saturaded with ammonia


The plant is 3000 Refrigerating Ton . Te= -8ºC TC= 35ºC


Question
How can we avoid that the ammonia discharge arrive to the atmosphere?


Appreciate the discution
Gwapa

Josip
11-03-2014, 11:16 PM
Hi, gwapa :)


Dear all
We are involved in a project to pipe all the discharge valve to a tank. The vessel should be able to diminish the impact of the ammonia discharge to the atmosphere


We thought to use a water spray and to bubble the ammonia in water. The issue is get rid of the water after it be saturaded with ammonia


The plant is 3000 Refrigerating Ton . Te= -8ºC TC= 35ºC


Question
How can we avoid that the ammonia discharge arrive to the atmosphere?


Appreciate the discution
Gwapa

My opinion is .... you are spending a lot of money for nothing ...
this is my opinion and I believe the best is to be direct ...

On your plant you have only a couple of safety valves to discharge liquid ammonia in case of opening ... i.e. oil separators under LP separators and maybe some other liquid line where you need protection due to not good design ... those safety valves discharge lines you can lead into your tank with water ... after day or two when dissolved ammonia evaporate you can use that water as a fertilizer on empty soil i.e. without crops or grass it will happen nothing ...

all other safety valves, I assume, are installed on gas pipes ... so if one of those valves act all gaseous ammonia is going into air ... ammonia is not harmful for mother nature - it has no impact to atmosphere, it is there since beginning of creation of atmosphere --- otherwise we have to close all dairy farms some of them with couple of thousand cows ... sounds strange ... but I do believe many refrigeration plants has been build with money made by the same cows !?!

all nowadays games ... (of smart ar..s which do not have even an idea about ammonia) to promote a stupid laws, regulations, whatsoever to protect the world of dangerous ammonia (what about so many dirty flares within refineries or other dirty industries) actually is promotion of installation of plants with refrigerants known as silent killers ... that is reality and we have to take care to not be suffocated by them .... ammonia is dangerous but always will tell us ... I'm here don't come to close without protection ... only a friend will do the same.

BTW, I was a witness to extremely stupid protection on ammonia plant here in my country ... they build something like a pool with about 1/2 m high concrete walls within engine room around compressors to protect liquid and gaseous ammonia to reach a rain sewage .... so in case if we have sudden release of liquid ammonia you cannot see anything and on the floor they installed concrete walls to jump over during run-out of engine room ... means if ammonia does not kill me I will fall over this concrete wall and make suicide ... it was not good to have a flat floor without obstacles ... in my sig the second one is about power of large group of s....d people ...

Sorry, if I sound rude, but I'm really sick of new laws, regulations, rules where most of them are without common sense ...

I would like to read some other opinion.

Best regards, Josip :)

gwapa
12-03-2014, 01:42 AM
Hello Josip
All your word are correct and I agree with you but do not help with my question


The plant is located just in the middle of the town of 6.000.000 million souls


100 year ago the plant was located outside the city where there was a lot of cows,dogs snakes and deer. Today two highway goes along the factory , there are schools etc.
So the local law do not allow vent any ammonia to the atmosphere . Also the water with some grade of ammonia you can not drain to public sistem because some ammonia vaporize and get out in any drain 100 mt arround.


We are thinking in three different way a) use CO2,b) any relif valve discharge must goes to the sucction of compressor and recondence again c) burnng it


I don't want to use water becouse the water can not be drain or vaporize
Gwapa

PaulZ
12-03-2014, 02:30 AM
Josip
I agree with you 100%, it's becoming increasing hard to do our work and all because of some ill informed people.

Gwapa
I have seen a few plants here that have water tanks and the ammonia is vented into them. I know of one site where a relief did lift and vent into the water but this was only for a short time and we never changed the water. I think from memory there is about 20,000 litres of water, this will hold a lot of ammonia. The release through a safety relief is a last resort and if all other safety devices are working properly and checked regularly this should not happen. If for some reason the water did become so saturated it had to be changed it would be treated as any other hazardous substance and disposed of. Question is how often is this going to happen. A well maintained plant is pretty safe and the chances of a relief lifting are very small, I would spend the money on making sure there was enough protection.
My opinion only.
Paul

RANGER1
12-03-2014, 10:12 AM
Gwapa,
You could consider a few things, but whether they suit your situation.
Protection of compressor use high pressure switch/ transducer or both.
set high stage 10-15% below liquid receiver relief.

low stage discharge same as above, but below intercooler reliefs.

each compressor bypass between discharge & suction with correct size for full load operation.
this valve has to be balanced port relief.

each screw is forced to unload before suction to discharge opens.

all relief valves off all vessels vent to low side vessel with balanced port reliefs.

low side vessel has suitably sized relief which can vent to atmosphere or water tank.

The only possible downside is if you can install stop valve on relief vent line into low side vessel for future servicing. Maybe a valve that can be locked with a procedure to operate.

just ideas, might help your situation

gwapa
12-03-2014, 05:27 PM
Paul/Ranger1
You have a plant located in middle of the city so we have to take all the necesaries protections to avoid to vent ammonia to the ambient .
The state law is pushing the factory to move to inside the country and this will cost a lot. So the plant has proposed to install all the devices to avoid any contamination to the ambient
The local temperature is 24-30ºC so as the water can absorb 25% of amonia (weight)
A 20000 l tank could absorb 5000Kg of ammonia. not bad
Now how to reclaim de ammonia adsorved for the water?

passandscore
13-03-2014, 01:55 AM
Once the tank is saturated have a Vac truck empty and dispose of it. That`s how I do it.

Tycho
13-03-2014, 06:33 PM
Depending on cost, there are also ammonia scrubbers that can be installed on the safety pipe.

Of course, the question is, what is cheaper, an ammonia scrubber that needs maintenance or a 20.000 liter pool of water that can be replenished by rainwater.

The problem (at least here in Norway) occurs when you have to dispose of the contaminated water and you have to pay a specialist company to remove and destruct the water/ammonia mix.

the basic of ammonia scrubbers are simple, you have a vent tower with a recirculation of a water/sulfuric acid mix, at the top of the tower the water mist is sprayed downwards into a reservoir and recirculated again and again. and the ammonia is vented up against the water mist.

with the water/sulfuric acid mix it is possible for the water to absorb many times more the amount of ammonia than it would as just water, the ammonia crystallizes in a salt form and can be collected in a solid salt form from the collection tray at the bottom of the scrubber.

I tried to find the principle behind it, but only found this supplier http://www.pollutionsystems.com/ammonia-scrubbers.html

Tycho
13-03-2014, 06:39 PM
Forgot to add that since since we are talking about securing the discharge from the safety lines, which should "never" release any gas, it would be a more cost effective solution to have a pool or container of water to pipe the lines into rather than installing a scrubber that would need regular maintenance.

Tycho
13-03-2014, 07:00 PM
Hi, gwapa :)



My opinion is .... you are spending a lot of money for nothing ...
this is my opinion and I believe the best is to be direct ...


all other safety valves, I assume, are installed on gas pipes ... so if one of those valves act all gaseous ammonia is going into air ... ammonia is not harmful for mother nature- it has no impact to atmosphere, it is there since beginning of creation of atmosphere --- otherwise we have to close all dairy farms some of them with couple of thousand cows ... sounds strange ... but I do believe many refrigeration plants has been build with money made by the same cows !?!

Sorry, if I sound rude, but I'm really sick of new laws, regulations, rules where most of them are without common sense ...

I would like to read some other opinion.

Best regards, Josip :)

Hello Josip :)

I edited your post in my quote so I could reply to a few points :)

Gwapa says that the plant used to be situated in an uninhabited area, but as time went by, there is now a lot of population around the factory.

The concern is not about the environmental hazard (which is nonexistent), it's about the smell and toxicity of ammonia for humans.
Since this factory is now in a densely populated area, a discharge from the safety lines could on a windy day be blown across the highway he mentioned, or an otherwise populated area. The officials focus on the safety discharge line, since that is what it is (safety... discharge), and they make rules for that specific part of the system.
Also, regulations across europe are moving towards all poultry, dairy and other kinds of farms that have ammonia as a by product have to have ammonia scrubbers installed (because of the smell).

Anyways, the officials have to take into consideration the most likely source of an ammonia discharge, which are the safety lines. they could of course order the plant to move it's location if they considered it to be a hazard in itself by having 3 tons of ammonia in a populated area, but then they might loose jobs for their citizens of other incomes they have from having a factory in their area :D

Josip
14-03-2014, 12:26 AM
Hi, gwapa :)


Hello Josip
All your word are correct and I agree with you but do not help with my question


The plant is located just in the middle of the town of 6.000.000 million souls


100 year ago the plant was located outside the city where there was a lot of cows,dogs snakes and deer. Today two highway goes along the factory , there are schools etc.
So the local law do not allow vent any ammonia to the atmosphere . Also the water with some grade of ammonia you can not drain to public sistem because some ammonia vaporize and get out in any drain 100 mt arround.


We are thinking in three different way a) use CO2,b) any relif valve discharge must goes to the sucction of compressor and recondence again c) burnng it


I don't want to use water becouse the water can not be drain or vaporize
Gwapa

I'm sorry,

in spite of my "rude" post that doesn't mean I do not want to help you .... it was not clear for me what is your situation from your first post .... there are very good suggestion given by other respected members with a lot of experience how to handle ammonia i.e. how to protect people.

For sure your task is not easy, but there are possibilities with acceptable solutions.

That plant isn't small at all ... as you said about 10,5MW ... maybe you can give us some more info ... what kind of plant is that one, quantity of ammonia within plant, no of compressors installed ... one or more systems ... all in general ...

Best regards, Josip :)

gwapa
14-03-2014, 10:10 PM
Tycho
It is a very interesting idea. I was thinking to use CO2. I know that CO2 and ammonia make a salt but I do not know what happen with ammonia + water+ co2.
do you have any experiencies on it?
Gwapa

gwapa
14-03-2014, 10:30 PM
josip
Besides Moderator you are generally nice guy:D
I also love to ammonia. I agree with your words and will always be welcome
The Plant is a brewery and produces 45 million liters per month
This has two receivers in parallel of 13 m3 each typically filled to 3/4
It has a recirculation system for ammonia fermentation tanks of 10 m3 half full
Ammonia traps has two parallel each Tr 1500
further having a set of flooded evaporators for process areas etc.
There is a system which has propelin glycol shell and tube coolers flooded this can be 600 Tr
There are screw compressors from 250 to 500 Tr
Evapcondenser 600 Tr
The total load is 3000Tr Te -8ºC TC 35ºC
The local ambient Tb temperture minima 20 maxima 30ºC
Best regards
Gwapa

RANGER1
14-03-2014, 10:47 PM
Gwapa,
In my part of the world this plant would be updated for a smaller refrigerant charge.
Usually chilled water or brine is pumped out to jacketed tanks etc for fermenting.
Plant room has plate heat exchangers so ammonia charge is kept to a minimum.
CO2 recovery system also installed to keep efficiency & costs down for operation of
plant.
This type of thing does not happen overnight, but something to aim for in the future,
especially in populated area like yours.
Pipework & valve station inspections would also high on the priority list. At these temperatures
corrosion would be a high possibility due to condensation on pipwork etc

gwapa
15-03-2014, 04:59 PM
Ranger1
We made a project to reduce at a minimun the ammonia to the room machinery alone. However there are a lot of fermenter tank that use ammonia jacket and it use mmonia recirculated. The glycol cooler are flooded type. All the co2 recover plant is located in the room machineries.
So the amount of relive valve are very few However these few valve could be very scandalous if they open up to the atmosphere
The HCL to neutralize the ammonia water solution is not easy to manipulate
What do you think to use Acetic Acid (vinager) to neutralize it? The group has a Vinager plant and is ese to use. You know to transporte the HCL und handle you riquiere to have special permit
Gwapa

RANGER1
15-03-2014, 10:15 PM
gwapa, sounds good also citric acid is good as well.