Urea

[Walcam]

I am finding it very hard to find Urea to buy in Denmark (or i am looking the wrong places...)

I did find Addblue which is 33% urea and rest destilled water, but is this good enough or do i need it pure?

 

[FrugalRefiner]

You don't need urea. If you're wanting it to deNO_x a solution, use sulfamic acid instead.

Dave

 

[anachronism]

You don't need urea. If you're wanting it to deNO_x a solution, use sulfamic acid instead.

Dave

It will be spelled Sulphamic Acid in Europe Dave. 8) 8) 8)

 

[kernels]

And is often sold as tile grout cleaner.

 

[Gdcole]

Probably won't be able to get this exact same thing, but as was mentioned, I found this in Ace Hardware, and was said to be used as a grout cleaner/residue removing product for $7.99. Not sure what the monetary conversion is.

 

[stella polaris]

Urea can be sourced by the tons at farmers co-op.
Better quality from the farmacy or a supplier of school chemestry.

 

[Jmk88]

I’m going to catch flack for this....

But I would use urea over sulphamic all day long. You would be wise to understand quantity required as sulphamic isn’t an economic way at all of denoxing. For me any way.

Adblue is absolutely fine and will react within 2 mins if done properly.

I’ve used adblue for my last 5 refines and will not be going back to sulphamic ever. It’s very very expensive stuff and hard work in my opinion.

It adds hours to my process and never seems to fully Denox either but that I would imagine is user error.

If you have no need to heat, which you shouldn’t at this stage, you won’t need to worry about the explosive risk of urea nitrates as you’ll be ready for precipitation and treatment of waste.

 

[jarlowski1]

I just bought 5 pounds of sulfamic acid from amazon for $20 free shipping.... That 5 pounds will last me a very long time. If you are careful with the additions of nitric than you really don't need much. If you are making poor mans AR than start figuring how much nitrate you wasted by having that much in excess and factor that into your cost. Maybe then you will realize the way you are doing it probably is costing you more money. Not trying to sound rude, just trying to point that out in case you may have overlooked that.

 

[Jmk88]

No it’s not just the cost for me. I like simplicity and urea for me is simple and quick.

I have had success with sulphamic but even at the cost you’re citing, 5l of adblue costs 5.50£ which should last you years.

That still far outweighs sulphamic at your price which is very good. I haven’t been able to get it anywhere near that cheap.

 

[Ariantila]

Nice posts, thank you all guys for your efforts.

 

[a_bab]

It it just me or the urea can't remove the excess nitric in solution; it would only remove the dissolved NOx gasses?

While the sulfamic acid would completely remove the nitric acid by converting it to N2O:

HNO3 + H3NSO3 → H2SO4 + N2O + H2O

And btw, urea nitrate in solution is not dangerous at all.

 

[Goldenrod757]

I have oft used the tricky boiling method, losing value in splashes when it 'bumped' . later on i learned finer control by reduced heat thru a sand bath. Only once did i use urea. It was very time consuming ,possibly because i had too much excess Nitric Acid, but i was very concerned about the Urea purity also.... Doesnt urea come with a coating of Urea Formaldehyde to reduce sublimation losses in storage?