The problem with NOx

[PhilG70]

Good evening.
With all this talk about the possible bans on diesel vehicles in city centres and other parts of the country  (starting with London) and the problem being the NOx emissions (not C02).
I've read conflicting reports/info about NOx and Biodiesel, some saying that Nox is greatly reduced (the hopeful outcome), some say that NOx is actually increased while others state it depends on the manufacturer and the exhaust/catalytic system they use.
1 Does anyone have a definitive concerning the affects/levels of NOx with Biodiesel usage?
2 Is there a reliable and trusted additive which can be added to the Biodiesel production process to reduce/eliminate the NOx levels?

I'm in between vehicles at the moment but depending on the reliability of the info and the effectiveness of the additive (if there is one).
It will obviously mean that people like me (who will not use diesel) finding a place to test their vehicles B100 Biodiesel emissions, then applying to the the DVLA for an alternative tax class, moving away from a diesel classification and possible bans or tolls for driving a diesel vehicle.

I don't mind the read, feel free to point me to any resources/websites I may have missed.
Thanks.

[therecklessengineer]

Yes - the fuel makes no difference to the NOx that the engine produces.

NOx is the result of Nitrogen and Oxygen from the atmosphere being smashed together at high pressures and temperatures - like in a diesel engine. It's inescapable, although through engine design it can be mitigated with exhaust gas recirculation and selective catalytic reduction.

So running bio won't make any difference to NOx.

[PhilG70]

Thanks for the response recklessengineer.