[anthell]

I want to improve our company's packaging strategy for live seafood products.

The catch is, the box has to be sealed completely.
This causes problem with the ever increasing level of co2 and not enough o2.

Now, since the box is tightly packed with the products and other materials for cushion (imagine
pieces of shredded paper or some sort), i am thinking of mixing a little bit of grinned calcium hydroxide powders in to the shredded paper cushion.

As far as i can gather, this is not recommended because calcium hydroxide can cause irritation right?

now, can anyone clarify on this? or give alternate solution for my problem?



While we are at it, is there anyway i can provide oxygen in this confined space? The box would not be returned so if the method is very expensive, i wouldn't be able to do so.
Is there simple chemical reaction that is relatively cool/cold (the seafood product loves cold temperature), and safe ?
i would like to experiment if i can provide enough o2...

If however, there is a much simpler method, i would love to hear about that too.

[curiouscat]

Try limewater? Ca(OH)2  shouldn't be irritant in dil. solution. You could also try lye.

Monoethanol amine is another option. Activated Carbon might also be worth a shot.

Slow Oxygen generation is a harder problem. How long is the shipping duration?

[anthell]

1. Lime water : so i just pour it / mix it with the shredded paper?
2. What is the different between lye and calcium hydroxide? arent they both irritant? any advantages?
3. monoethanol amine, how do i go about using this ? mix also?
4. Activated carbon, how also? The shipping container doest not have air circulation system, would activated carbon still work? isnt it more like a filter?


Oxygen.

so far, we have successfully shipped it over 20hrs+ however, we are looking to go to around 40hrs+

[Arkcon]

Perhaps there are industry available environmental scrubbers for just such an application.  Have you ever seen any sort of canister in a seafood shipment for this purpose by another vendor?  Maybe a shipping container manufacturer has such an option available.   Just mixing some random chemical, with the packing material, on your own, without consulting the regulatory board would likely be a bad idea.  That won't accept your assurances that its all perfectly safe.

[curiouscat]

As an aside, if you ever ship in a lorry across the Channel Tunnel or a Ferry you may have a good chance of giving the immigration people some excitement. Apparently they look for stowaways using CO2 detectors in shipping-containers these days! Thank goodness lobsters don't have heartbeats!

[vmelkon]

Put some humid Ca(OH)2 in a plastic container. Spraying a little water on it will do the job. If you can use dissolved Ca(OH)2, that's even better. It will form the very non soluble CaCO3. I don't consider Ca(OH)2 dangerous.
As for NaOH, this is very hygroscopic and also caustic to skin. It will also react with aluminum. However, NaOH is a very good CO2 absorber. Its solubility in water is much higher than Ca(OH)2.

monoethanol amine is a liquid and it is dissolved in water when uses as a CO2 scrubber.

[fledarmus]

You might look at rebreather designs. These have a lot of the same issues - too much carbon dioxide formed, oxygen needs to be constantly added. These mostly use soda lime cartridges to absorb the CO2, with an indicator to let you know when the soda lime is used up.

There are also some rebreather designs that use potassium superoxide - it absorbs carbon dioxide and releases oxygen at the same time: 4KO2 + 2CO2 = 2K2CO3 + 3O2. Unfortunately, if you get it wet, very nasty things happen.

[Arkcon]

Interesting.  The potassium superoxide, in something like a small steel canister, open at both ends, sealed over with a porous Teflon membrane might be the thing you want.  Water won't get in, assuming the metal to Teflon seal never fails.  But gases will get in and out.  But can you guarantee proper airflow so that it has a useful effect on the shellfish, you'd have to try it and see.

[anthell]

Thank you so much for all the replies, sorry for not answering earlier on as i was actually trying out the ideas you guys suggested.

The experiment with lime water seems / caoh seems to be doing fine as recommended by you guys, but the stuff like monoethanolamine is rather complicated to obtain..

I want to ask some stuff regarding the KO2 u guys suggested, especially the part when you said water makes rather nasty...

Basically, being aquatic animals, in the holding tank they are always wet. Before the transport, they are being dried, thats for sure, but is that sufficient?
Would moist/humid condition triggers the nasty thing? if so.... just how nasty? is it worth the risk?

I was thinking of just adding the KO2 over to the packaging materials, but if its better to use the membrane then i guess that works too.

thanks!!

[curiouscat]

Look at the cost too. Lime's cheap; but I don't know how much KO2 sells for. Will the economics work out?

[anthell]

I havent got the clue about the price yet lol...

rather, Im very much interested in the membrane mentioned...

watertight, but non airtight, any suggestions of what are the examples of commercially products that fits that?
it would be exceptionally helpful if links to websites that sells them can be provided, or any suggestions of technical names for those stuff would really help too so i know what to look for

thanks