Why use Adblue and not use 100% Urea?

[James125]

Hello all

I am puzzled as to why SCR uses Adblue solution which is only 33% Urea. Why not use 100% Urea minimise fill ups and weight?

Thanks

 

[xxChrisxx]

because it's ammonia that is needed, not urea. You don't have enough water floating round to react in time. So you are injecting both reactants.

 

[James125]

Stupid question really Urea is a solid. It's solubility in water is 107.9 g/100 ml @ 20 °C. Presumably 33% at -10C or something.