Diesel scrapage scheme 2017

[forddeliveryboy]

When a DPF burns the trapped particulates surely they then turn into smaller particulates. These must be more easily distributed and inhaled, or am I wrong?

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It's a massive problem which the authorities are keeping quiet about in the UK.

 

As is the fact that more than half of road transport particulate pollution comes from tyres and other friction materials.

 

It's vehicle mass we should be concentrating on - not a 5, 10 or 15% reduction but 35 or 45 and more.

[PiperCub]

Never really looked into it and correct me if I'm wrong here but it always seemed to me that with DPF's etc, you aren't so much curing a problem, more moving it around/changing it's location?

[AMC Rebel]

Never really looked into it and correct me if I'm wrong here but it always seemed to me that with DPF's etc, you aren't so much curing a problem, more moving it around/changing it's location?

 

I think this is true of quite a bit of emissions "technology".  A lot of it seems really crappy to me - but I admit to having a limited knowledge of what is called STEM these days.  

 

EGR is another example - doesn't anyone else think that if there is so much unburnt fuel coming out that it needs routing back in for another go, the engine design (or maybe the entire concept of the ICE) must be a bit crap?

 

Same for those air injection systems the Yanks used to fit.

 

If memory serves, the Japanese were hoping to use lean burn petrol engines to do without catalysts (which seemed like win-win) but the rest of the world (especially the USA) said no. 

[Dave_Q]

Lean burn pez is a great idea, but will increase NOx which is the current baddie du jour.

 

On a diesel, increasing combustion temperatures and pressures create more NOx due to dissociation of N2 and O2 (air)

 

Increasing combustion temperature also reduces particulate emissions, but you can't win at both at the same time. 

 

 

 

Ultimately, the only proper solution is to sort out battery and charging technology, generate our electricity cleanly from tidal etc, and a large change in consumer attitudes to how much vehicle mass and power is required to sit in traffic on the M62.

 

(IMO: <500kg and <50hp.)

 

Until then, be prepared to pay/be taxed through the nose for incremental "improvements" that are no better than driving a 1950's Cadillac in the grand scheme of things.

[M'coli]

EGR is another example - doesn't anyone else think that if there is so much unburnt fuel coming out that it needs routing back in for another go, the engine design (or maybe the entire concept of the ICE) must be a bit crap?

EGR isn't to re-try burning unburnt stuff, but it's to reduce the temperature of combustion and reduce the NOx that's generated. It also has the benefit in petrol engines of being able to improve fuel consumption by raising the dynamic compression ratio on part-throttle, not dissimilarily to the idea of lean-burn engines.

[AMC Rebel]

EGR isn't to re-try burning unburnt stuff, but it's to reduce the temperature of combustion and reduce the NOx that's generated. It also has the benefit in petrol engines of being able to improve fuel consumption by raising the dynamic compression ratio on part-throttle, not dissimilarily to the idea of lean-burn engines.

 

Thanks - told you I didn't know what I was talking about

 

It still seems like a crude mechanism to me - couldn't water injection do a similar job?

[lisbon_road]

I'd like to ask some questions.  

 

1) these nano particles that modern diesels are supposed to emit.  Do older ones, which clearly emit larger particles, emit them as well?

2) we've apparently seen high levels of NOx from diesels in (say) the last 15 years.  I've seen graphs that reckon they were about the same for Euro 1 onwards.  What were they like for really old diesels?

3) I get the feeling that a scrappage scheme, were there such a thing, would need to apply to anything euro 5 backwards.  Is that right?

4) Euro 6, I think, restricts the level of NOx more effectively by forcing Adblue based systems.  Does it really do anything for the very small particles?

5) I appreciate that NOx is nasty, but is it right to think that the nano particles are worse?

 

If anyone knows any of this stuff for real, be very interested.  If not just ignore my post.  Thanks.

[Ditchfinder General]

It's expected of you to have a white Audi A4 Sportline, work in HR, have a Fit Bit and an I-phone.

 

I live on a new build estate and I've got an elderly Rover 75 as a driveway ornament.

 

I bet the neighbours look down their nose at me but I couldn't care less. 

[AMC Rebel]

Makes you wonder if anyone asked a real scientist* if DPFs were a good idea?

 

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They probably asked Trump or one of his mates.

[Craig the Princess]

 

As is the fact that more than half of road transport particulate pollution comes from tyres and other friction materials.

 

It's vehicle mass we should be concentrating on - not a 5, 10 or 15% reduction but 35 or 45 and more.

To quote from Defra's air quality report brake and tyre wear account for 23%. Re-suspended road may account for more but short of taking lorries and buses off the road for trains and trams it seems a bit of a red herring.

 

"

Considering the road transport sector, tyre and brake wear emissions in 2001 accounted for ~23% of the total road transport emissions. Resuspended road dust also makes an important contribution, one that is not accounted for in national estimates of UK total PM10 emissions. Recent work suggests that the resuspended component of PM10 can be as large as, and in some cases much larger than, exhaust emissions.'

 

 

"In addition, both tyre and brake wear and resuspended PM10 appear to be much more important for heavy duty vehicles than for light vehicles such as cars. "

[AMC Rebel]

It's expected of you to have a white Audi A4 Sportline, work in HR, have a Fit Bit and an I-phone.

 

Ha ha my ex (now) lives on an identikit estate, drives a year-old white Juke on a lease, has a fitbit, iphone, ibook and 2 ipads - all of which might give some clues as to why she is an ex.

[castros_bro]

When a DPF burns the trapped particulates surely they then turn into smaller particulates. These must be more easily distributed and inhaled, or am I wrong?

 

Sent from my X17 using Tapatalk

 

Yes/No*   The idea is DPF stops the particulates being emitted with the exhaust gases then, as the trapped particles are unburnt carbon, during the  "regen"  cycle the trapped carbon particles are burnt so become carbon dioxide and part of the the exhaust gasses.   You may now breathe in and exhale this carbon dioxide.

 

 

*Ignore as artichoke

[angle]

I'd like to ask some questions.  

 

1) these nano particles that modern diesels are supposed to emit.  Do older ones, which clearly emit larger particles, emit them as well?

2) we've apparently seen high levels of NOx from diesels in (say) the last 15 years.  I've seen graphs that reckon they were about the same for Euro 1 onwards.  What were they like for really old diesels?

3) I get the feeling that a scrappage scheme, were there such a thing, would need to apply to anything euro 5 backwards.  Is that right?

4) Euro 6, I think, restricts the level of NOx more effectively by forcing Adblue based systems.  Does it really do anything for the very small particles?

5) I appreciate that NOx is nasty, but is it right to think that the nano particles are worse?

 

If anyone knows any of this stuff for real, be very interested.  If not just ignore my post.  Thanks.

(1) - Yep.

 

(3) - In London, the ULEZ will mean your diesel needs to be Euro 6 or higher so that seems like a reasonable guess. Assuming something like this comes in around 2020 though, that means you're encouraging people to scrap five year old cars. I can't see that going down well and in London people that live in the ULEZ will get given a 'sunset period' of a few years to change their car.

 

(4) - The difference between Euro 5 and Euro 6 for diesels is just a tighter NOx limit - no difference to other emissions

 

(5) - the short answer is that no one knows as the two are so closely linked it's difficult to measure. The best guess work done for the ULEZ suggests that NOx is responsible for more deaths but particulates cause a wider variety of health problems.

 

(Disclaimer - the above post is based on pub conversations with people who know what they're talking about, I don't really)

[AnthonyG]

I severely doubt there will be a scrappage scheme, they can just ban all diesels of a certain age or Euro spec from the relevant city centres and let market forces do the rest. Paying people money to buy new cars doesn't really fit with 'austerity' politics.

[alcyonecorporation]

Paying people money to buy new cars doesn't really fit with 'austerity' politics.

They manage to pay politicians to do sod all in regards to representing their constituency. The government can do anything if it wants it done badly enough.

[cros]

 

If memory serves, the Japanese were hoping to use lean burn petrol engines to do without catalysts (which seemed like win-win) but the rest of the world (especially the USA) said no.

 

Honda and, I think, Chrysler sold early versions of stratified charge engines at one point long ago. I think an extra inlet valve fed mixture from a small carb to part of the combustion chamber nearest the plug. What with that and 5 valves with oval pistons you can't say those Honda folk weren't trying.

[alcyonecorporation]

Honda and, I think, Chrysler sold early versions of stratified charge engines at one point long ago. I think an extra inlet valve fed mixture from a small carb to part of the combustion chamber nearest the plug. What with that and 5 valves with oval pistons you can't say those Honda folk weren't trying.

Oh christ I remember Honda's oval piston engine. What a random piece of kit that was - were they hoping for better emissions from it?

[castros_bro]

 

 

If memory serves, the Japanese were hoping to use lean burn petrol engines to do without catalysts (which seemed like win-win) but the rest of the world (especially the USA) said no. 

 

Will that be  (Royal) Enfield's of India AVL engine designed in collaboration  with Austrians and some Brits which sold world wide unfortunately including North America? 

http://www.haywards.co.uk/electra-x.html

[alcyonecorporation]

To quote from Defra's air quality report brake and tyre wear account for 23%. Re-suspended road may account for more but short of taking lorries and buses off the road for trains and trams it seems a bit of a red herring.

 

"

Considering the road transport sector, tyre and brake wear emissions in 2001 accounted for ~23% of the total road transport emissions. Resuspended road dust also makes an important contribution, one that is not accounted for in national estimates of UK total PM10 emissions. Recent work suggests that the resuspended component of PM10 can be as large as, and in some cases much larger than, exhaust emissions.'

 

 

"In addition, both tyre and brake wear and resuspended PM10 appear to be much more important for heavy duty vehicles than for light vehicles such as cars. "

Got a link CTP?

[Craig the Princess]

Got a link CTP?

Here you are https://uk-air.defra.gov.uk/assets/documents/reports/aqeg/ch4.pdf

[alcyonecorporation]

Here you are https://uk-air.defra.gov.uk/assets/documents/reports/aqeg/ch4.pdf

How recent's this report? I was reading an EEA document with a similar remit last night.

[AMC Rebel]

Will that be  (Royal) Enfield's of India AVL engine designed in collaboration  with Austrians and some Brits which sold world wide unfortunately including North America? 

http://www.haywards.co.uk/electra-x.html

I was really talking about cars - from memory, Toyota were trying to do lean burn for cars, but the USA and EU decided to legislate for cats instead.  

 

That engine looks interesting though - I guess fitting a cat to a motorbike is more challenging.

[Craig the Princess]

How recent's this report? I was reading an EEA document with a similar remit last night.

I can't find a date on the report but the date reviewed includes 2010 so around 2012/2013.

[forddeliveryboy]

There are several academic papers researching non-exhaust emissions, going back to the 1980s but in general it's a poorly-understood science. I've read a few, the report to the House of Commons last year sums things up as well as any.

 

It's not difficult to measure the mass of tyre rubber and other friction materials used every year on UK roads, the awkward bit is working out what the particle size distribution (and re-distribution) is.

 

From https://www.publications.parliament.uk/pa/cm201617/cmselect/cmenvfru/665/66504.htm - the last para of what I've copied below sums up what we're discussing, but there are reports I'll try and dig out which talk about figures of 70%+ for non-exh particulates on busy motorways.

 

" 21.Defra’s policies must support technological developments to reduce particulates generated by the wear of vehicle brakes and tyres; the Government must commission by 21 July 2016 an assessment of any policy or research gaps on the level of emissions from these causes and methods for reducing them. The Department must ensure that EU and UK regulations reflect emerging scientific evidence on pollution from wear and tear of vehicle operation.

 

(Paragraph 64)Defra is aware of the importance of brake and tyre wear as a source of particulate emissions having commissioned our own independent research on PM2.5, which was published in 2012 and 2015 by the Air Quality Expert Group (AQEG).6 7 8The relative contribution of a range of sources, including non-exhaust particulates, is estimated annually through the National Emissions Inventory9 (NAEI). The NAEI is reviewed and updated annually and is alive to changes in methods and understanding of brake and tyre wear, which are incorporated into the updated emission factors developed under this program. The latest Informative Inventory Report explains, in section 3.3.3.7 (p.146), how non-exhaust emissions of particulates from tyres, brake linings and the road surface are estimated when producing the UK emission inventory.

 

10The NAEI was cited in a comprehensive review by the Joint Research Committee (JRC) in 201411 on brake and tyre wear, which showed that the estimated emissions published in the NAEI were in agreement with the latest scientific research and other EU emissions inventories.

 

The JRC review showed that non exhaust PM accounts for approximately half of transport derived PM (the other half being from the exhaust) and that this proportion has been stable for many years. However, it also highlighted the likely changes that may emerge as exhaust emissions are cut due to abatement technologies. This may lead to brake and tyre wear becoming a more dominant source of particulates than tail pipe emissions."

[forddeliveryboy]

I've probably told this story before on here, but it's relevant to this thread.

 

My old MoT tester used to slide the workshop doors open a few inches when smoke testing diesels, to allow a flow of air through the testing bay. It was a large, airy bay. Having done the same with one of the first common-railers, he saw stars, felt dizzy and took the best part of an hour to recover.

 

From then on, the doors stayed wide open even on the windiest, coldest day if a CR dizzler appeared - I took note, wondering how many years of academic research and parliamentary bullshit it would take until the public was informed that these supposedly clean diesels which garage smoke sniffers suggest exhale near fresh air were much more poisonous than what they replaced.

 

As diesel-engined cars turned from faithful sloggers into snappy performance machines, the problems multiplied. All the while, official government proper-ganda suggested tailpipe emissions were falling year on year - it took until around 2009 before King's College London started asking questions, based on real data.

[Negative Creep]

Well at least we now know what they'll "discover" to raise taxes on EVs and electric cars. Give it 15 years and tax will be based on vehicle weight to compensate for that nasty brake pad and tyre wear

[oldcars]

I live on a new build estate and I've got an elderly Rover 75 as a driveway ornament.

 

I bet the neighbours think i am a total winner. 

fify

[M'coli]

Oh christ I remember Honda's oval piston engine. What a random piece of kit that was - were they hoping for better emissions from it?

No - they designed it to try to compete with 2-strokes in motorcycle racing. The only way to get the revs they thought they needed was to have a short stroke, with the restrictions on cylinder numbers the only way to get the valve area to let them breathe at 22000rpm was by having 8 valves per oval cylinder. Even now it would be difficult to achieve but in 1979...the answer was "no".

[Pete-M]

If they're offering straight cash for diesels they can have my E320 CDI tomorrow.

 

If it means I'm meant to buy some new pos, no.

[forddeliveryboy]

Without Honda persisting with their mad 32 valve V4s, it's possible there'd be no VTEC. I think they made those engines as they did because four was the maximum number of cylinders allowed and eight valves timed for power caused starting probs.

 

Didn't VW build an oval diesel, for very different reasons, sometime around when they introduced the original five pot TDi?