New emissions equipment: Exhaust Reactor? Wuzzat?

[ssgtbaloo]

I've looked around on line to try to understand the newest emissions add-on: the Exhaust Reactor. I couldn't find any articles that weren't about anything but regular old catalytic converters.

It's the first piece of emissions equipment introduced in the game, but I've never heard of it. What is it and how does it differ from a catalytic converter? Has it ever seen widespread use in the north-American market (the one I'm most familiar with)?

Can anyone share links to articles that explain what it is and what it does that differs from standard catalytic converters?

Thanks in advance.

[robert.norgren]

Maybe it's the type where fresh air is injected in the exhaust runners?
I notices that it was not available on all exhaust manifold types on a 1972 car I built.

[Slim Jim]

I'm assuming it's a smog pump or secondary air injection pump. https://en.wikipedia.org/wiki/Secondary_air_injection
https://www.motortrend.com/how-to/1504-understanding-how-a-smog-system-works-clean-living/#:~:text=The%20first%20smog%20pumps%20introduced,the%20pump%20using%20four%20bolts.

[[CAMSO] MrChips]

Exhaust (or thermal) reactors were used in the mid 1970s and early 1980s as a way for manufacturers to try to reduce their hydrocarbon/CO emissions to comply with California's stringent emissions rules without the need for a catalytic converter. It was essentially a device that would superheat the exhaust coming out of the engine and mix it with additional air in an attempt to burn some of the excess CO and hydrocarbons, but without the benefit of a reaction catalyst like a catalytic converter uses.

They were very short-lived in most applications because they created a lot of issues of their own from the heat they generated, and also because catalytic converters became cheaper and far more effective.

[robert.norgren]

Cool to get an easy to understand and informative answer.

[ssgtbaloo]

Thanks! I seem to recall there was an interim step between nothing and catalytic converters*. I remember reading how manufacturers were warning that one should not park in tall, dry grass because the exhaust system was so hot that it created a high risk of fire.

* Apart from Honda's stratified charge technology, anyway.

[Johno]

Seems useless for now if it increases Nox.

[MirkoC407]

Originally posted by Johno:

Seems useless for now if it increases Nox.

That's the balance you always have to meet. Real regulations do as well. Drove a Chevrolet Camaro here in Europe for some years and its standard engine management was quite lean, causing fewer CO and HC but more NOx according to US law. No chance to get through German emissions check every 2 years though. Needed another mapping for that, which reduced NOx on the price of more but still permitted levels of CO and HC - and increasing consumption from 12.8 to 14.3 L/100km.
So usually I had a friend with the according software flash to EU software before the check and back to US afterwards to save on fuel (and yes, in the greyest of all theories that was illegal - but no one would ever ask between the checks, which of course were fine every time). A less obscure way (it would ignite the service engine light though, which on an 87 Camaro is 2 x 4 cm in bright orange and therefore very obvious to the test engineer that something is odd here) would have been to simply short circuit two pins in the OBD terminal to send the engine into emergency running, which also will have it running rich enough.

[El Rushbo]

Kind of reminds me of the DPFs we have now for diesels. Same risk with excess heat in the exhaust when doing a regen.