Can somebody explain to me about urea injection and what it has to do with the DPF and reducing NoX

 

The following Link has all the information you could ever want regarding it. I've been using this site for alot of my research. The link i'm pasting is for a specific article describing the basics of NoX reduction and absorbtion as well as SCR (Selective Catalytic Reduction) AKA urea injection .
The other pages on the site offer a ton of research data regarding EGT's and reduction of NOx and other emmission gasses. Technology Guide: Paper Abstracts

I could type for days and you wouldnt know the half of it!