Diesel emissions

Orionaut

Orionaut

Orionaut

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Would anybody have access to any data comparing the NOX/Particulate emissions from Diesel engines from 30 years ago with more modern (Non-DPF/Cat) ones?

I am curious to know whether or not the more modern engines are inherently more polluting for NOX and fine particulates because the pressure for ever improved performance and MPG has pushed the technology somewhat

(IE I am considering the possibility that though Older engines were less powerful, only 30/40 BHP/Litre or so and less eficient. combustion temperatures were lower (Less NOX per KWhr) and the atomisation was less effective (More visible smoke, But perhaps less PM10/KWhr)

i would be interested to know whether actual data supports or debunks this idea.
 
They've been steadily falling with each new EU emissions standard. We are almost at the point of making it a non issue just as the hysteria has started to build.
 
The kind of information you want can be found in published peer reviewed journal papers.

In fact Burtscher (2005) wrote a paper titled "Physical characterization of particulate emissions from diesel engines: a review"

I've read the abstract and it looks like it contains the information you're after. Although you'll have to get hold of the paper and assimilate the information yourself.
 
Euro standards and limits during test - huge reductions.

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However we know there isn't much correlation between the two, particularly NoX.

You can see how petrol banning from citys allows down to Euro 4 (Jan 2005) but diesel much newer as Euro 6 nine years later only matches the NoX level.
 
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[TW]Fox;30391729 said:
They've been steadily falling with each new EU emissions standard. We are almost at the point of making it a non issue just as the hysteria has started to build.
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The problem is that there are far more older standard cars in use which means the issue is compounded going forward - i don't think the 'hysteria', rather, concern is unfounded given that they will remain in use for a number of years to come.
 
[TW]Fox;30391974 said:
So in theory then the NOX emissions of my 2001 530i are higher than those of my 2015 530d?
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I don't know how easily engines may have passed the standard and then the real world correlation between petrols and test.

http://equaindex.com/equa-air-quality-index/

Strong data to show petrols currently are a lot closer to test data.
 
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Also, some of the more recent diesels have a fluid which collects a lot of the harmful stuff, including NOX. The Audi version is called "Adblue" I think and their new cars won't even start if it runs out.
 
Thats selective catalyst reduction where the Adblue (urea) is injected and reacts post combustion in the exhaust to turn NoX into other cleaner Nitrogen + water. Most diesels need it to meet Euro6.... unless they cheat. Like VW.
 
There's a trade off between fuel efficiency and emissions. What would make the engine run more efficiently will mean more harmful emissions are produced. What will make less harmful emissions, will mean more fuel used, etc. I suppose a lot of the hysteria was around the misunderstanding and finding out that manufacturers were cheating the test. VW and their cheat device, BMW using cars with a cold engine, knowing it wouldn't pass once up to temperature.

It's only really the larger diesel engines that make use of DPF before SCR with fluid injection (Adblue), and as Jonnycoupe says the mixture reacts to turn NOx emissions that go on to cause acid rain (NO2 + H2O = HNO3, nitric acid) into nitrogen gas. This means almost all of the emissions are nitrogen, water vapour and carbon dioxide, with only traces left of more harmful stuff like NO, NO2, particulate matter and CO.

I think the diesels coming now really are up to scratch without requiring 'work arounds' by some manufacturers.
 
New diesels seem to be doing away with adblue and doing things differently, pretty sure my mondeo doesnt use it.

Edit: This is interesting in the different ways of dealing with NOx, seems to be at least three different ways of treating it. I know mine does a forced regen now and again where the mpg will drop and engine note changes for a few minutes.

http://www.dieselcar.com/features/euro-6-understanding-the-new-regulations/
 
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Orionaut said:
Would anybody have access to any data comparing the NOX/Particulate emissions from Diesel engines from 30 years ago with more modern (Non-DPF/Cat) ones?

I am curious to know whether or not the more modern engines are inherently more polluting for NOX and fine particulates because the pressure for ever improved performance and MPG has pushed the technology somewhat

(IE I am considering the possibility that though Older engines were less powerful, only 30/40 BHP/Litre or so and less eficient. combustion temperatures were lower (Less NOX per KWhr) and the atomisation was less effective (More visible smoke, But perhaps less PM10/KWhr)

i would be interested to know whether actual data supports or debunks this idea.
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I think you will find that a lot of the "less visible smoke" is down to modern fuels, not just emissions systems.

Don't forget that the actual diesel fuel itself has changed enormously over the last 30-40 years or so.

Pretty sure you would find that running a 40 year old diesel on modern fuel would reduce its emissions and visible smoke no end, compared to running it on the original fuel available when the vehicle was built, and that is before any emissions systems get involved.
 
robj20 said:
New diesels seem to be doing away with adblue and doing things differently, pretty sure my mondeo doesnt use it.

Edit: This is interesting in the different ways of dealing with NOx, seems to be at least three different ways of treating it. I know mine does a forced regen now and again where the mpg will drop and engine note changes for a few minutes.

http://www.dieselcar.com/features/euro-6-understanding-the-new-regulations/
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Mainly for packaging reasons and the fact that customers don't want yet another tank they will have to keep topping up.

On trucks buses coaches and larger vehicles Adblue is still the way to go as there are not so many packaging issues and the tanks can be so much larger they last far longer between fill ups.
 
[TW]Fox;30391974 said:
So in theory then the NOX emissions of my 2001 530i are higher than those of my 2015 530d?
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Not necessarily, it just implies that theoretically it could have have been whilst still within tolerance. If all vehicles are right on the limit then it would be true but I suspect that isn't the case.
 
robj20 said:
New diesels seem to be doing away with adblue and doing things differently, pretty sure my mondeo doesnt use it.

Edit: This is interesting in the different ways of dealing with NOx, seems to be at least three different ways of treating it. I know mine does a forced regen now and again where the mpg will drop and engine note changes for a few minutes.
Click to expand...

A regen is for the particulate filter, rather than a NOx trap.
 
I work for a bus manuafacter and we are moving away from Diesel buses in major citys as they are just not wanted anymore, we are testing Hydrogen, various Hybrid setups as well as full electric. I can honestly see no diesel bus sales in 10 years in major citys. Problem is everyone is just on the band wagon now as well
 
Entai said:
I think you will find that a lot of the "less visible smoke" is down to modern fuels, not just emissions systems.

Don't forget that the actual diesel fuel itself has changed enormously over the last 30-40 years or so.

Pretty sure you would find that running a 40 year old diesel on modern fuel would reduce its emissions and visible smoke no end, compared to running it on the original fuel available when the vehicle was built, and that is before any emissions systems get involved.
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I would be inclined to agree with that.

When I am feeling flush, (And before I go for the MOT test) I treat my old girl to the BP super diesel, It is my definite observation that I get a lot less smoke.

Thanks for replies.

However, it is not exhaust treatment or pollution reduction technologies that I am thinking about.

Think of it this way, A really filthy engine with good pollution reduction can be cleaner that a rather cleaner engine with no pollution control.

I am proposing the hypothesis that the drive for high specific performance and high fuel efficiency has made the basic engines much dirtier (Same applies to petrol too of course)

Basically, modern pollution control doesn't just have to clean up the pollutants that engines produced 30 years ago, It is actually having to clean up pollutants that are rather worse.

There are other issues with modern vehicles that also results in our running around in circles since an improvement in one area inevitablely results in disadvantages in others
 
MrKnifey said:
I work for a bus manuafacter and we are moving away from Diesel buses in major citys as they are just not wanted anymore, we are testing Hydrogen, various Hybrid setups as well as full electric. I can honestly see no diesel bus sales in 10 years in major citys. Problem is everyone is just on the band wagon now as well
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Which manufacturer do you work for?

I drive Enviro 400H's at work which are by far the nicest buses to drive compared to diesels.
 
MrKnifey said:
I work for a bus manuafacter and we are moving away from Diesel buses in major citys as they are just not wanted anymore, we are testing Hydrogen, various Hybrid setups as well as full electric. I can honestly see no diesel bus sales in 10 years in major citys. Problem is everyone is just on the band wagon now as well
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TBH that is a good thing. Diesel buses cause a massive amount of the road pollution in cities.

But I have an idea for an alternative. I call it...a tram. It's simple, it's just a bus on a an electric rail! Much more efficient than an EV and no batteries. Cheap to make because theres no engine and as long as people stay out of the way, they don't get killed :D
 
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