Naked Science Forum
Non Life Sciences => Technology => Topic started by: peppercorn on 16/05/2011 08:55:44
-
I'm suggesting legislation that puts more emphasis on CO2 in rural areas and more on NOx/particulates in urban areas, by means of on-board GPS.
And, yes I know, complaint number 1 will be "Why does Big Brother need to where I'm driving?"... plus the bazaar situation of having failed an MOT only on the GPS not working [:D]
The argument for doing this is obviously allowing good air-quality in cities, but not at the cost of CO2/fuel efficiency out of town.
-
What can you do about reducing the CO2 unless you have a hybrid? I suppose enforcement of a strict speed limit in rural areas would help; but then there is usually one in urban areas so this is tantamount to just having a reduced speed limit everywhere. I am also not sure what you can do, on the fly, about reducing NOx. The particulates could possibly be reduced by limiting acceleration.
I am not wholly sure these are very controllable parameters for a given vehicle. It may be better that resources are continued to be put in the cleaner and efficient engine design. There have been huge improvements in the last 10 years.
It will all be solved when the oil runs out anyway :-)
-
It will all be solved when the oil runs out anyway :-)
To true! Although 'solved' is perhaps not the description I'd go for [:o]
What I didn;t explain is there is for today's cars a general rule of thumb that decreasing NOx is achieved (admittedly to a very high standard) at the detriment of CO2, milage and other pollutants - therefore auto engineers are always struggling to balance these factors and the 'balance' they go for is heavily influenced by the air-laws (which differ slightly around the world). It could be argued that this 'influence' is second only to what the marketing men say the car needs to achieve in terms of performance/responsiveness, etc [::)]
The idea is, that by allowing the legislation to differ for rural areas compared with built-up ones, the engineers have the ability to switch the car's ECU map for a more energy efficient one when out of the city.
-
What can you do about reducing the CO2 unless you have a hybrid?
You can run the engine leaner, which will reduce CO2 by improving fuel economy. The dirty little secret about catalytic converters is that they consume fuel.
Catalytic converters are good for "townies" because they improve air quality in urban areas, but they are doing it at the expense of increasing CO2 production.
-
Ah, just read up a bit on the subject. I see that cats on lean burn engines have a problem getting rid of NOx products. Oh dear, more chemistry than physics this.
So the trade off is to allow the NOx and unburnt hydrocarbons in the countryside but have less CO2 and burn less fuel in this case. I see the point and it's a good thought to use the GPS technology to control this. It does not seem nice to exhaust these nasty things anywhere though and I wonder what percentage of the world's total greenhouse gas output would be reduced by, even if this were universally adopted.
What we need are cheap hydgrogen fuel cells.
-
What we need are cheap hydgrogen fuel cells.
Personally, I'm betting on mortadella fusion.
(I've been waiting for the cheap fuel cell for 50 years!)
-
So the trade off is to allow the NOx and unburnt hydrocarbons in the countryside but have less CO2 and burn less fuel in this case. I see the point and it's a good thought to use the GPS technology to control this. It does not seem nice to exhaust these nasty things anywhere though and I wonder what percentage of the world's total greenhouse gas output would be reduced by, even if this were universally adopted.
I think the nasty NOX and carbon monoxide products only create local smog problems before UV light causes them to decompose, but we really need BC to sort us out on that one.
The CO2 reduction might be quite significant (a few percent?) but it's not going to solve the real problem. Now, if we could figure out a way to recover the waste heat, that mighht be a different story.
-
So the trade off is to allow the NOx and unburnt hydrocarbons in the countryside but have less CO2 and burn less fuel in this case. I see the point and it's a good thought to use the GPS technology to control this. It does not seem nice to exhaust these nasty things anywhere though and I wonder what percentage of the world's total greenhouse gas output would be reduced by, even if this were universally adopted.
I agree it's not a world-beater solution, but I think the trade-off that engineers have been forced to make is quite substantial (I know, I know. I ought to go off and put some figures on this). But, what we can assume is that in a world (ie. the Western one) where GPS will become as ubiquitous as airbags & ABS - the implementation cost of a system like this will become almost non-existent almost immediately.
I think the nasty NOX and carbon monoxide products only create local smog problems before UV light causes them to decompose, but we really need BC to sort us out on that one.
The mechanism that leads NOx to become acid-rain involves sunlight doesn't it? I have to say it could be a case of robbing Peter (deforestation, etc)to pay Paul (saving human health). Again, I don;t know what levels of damage would occur from, say a heavily used motorway through a dense forest? Or it more about wind direct, or topology, or a million other factors... [???]
The CO2 reduction might be quite significant (a few percent?) but it's not going to solve the real problem. Now, if we could figure out a way to recover the waste heat, that might be a different story.
Yes. Recovering waste heat (or even not making it in the first place for fuel cells) would be lovely, but the technology for it has not (economically) arrived yet. GPS has.
Personally, I'm betting on mortadella fusion.
What is this? Google comes up with Italian sausage! [:D]
BTW, can we make a fuel cell yet that runs directly on E85?
-
Personally, I'm betting on mortadella fusion.
What is this? Google comes up with Italian sausage! [:D]
It was Graham's idea, honest! http://www.thenakedscientists.com/forum/index.php?topic=39244.msg356049#msg356049
-
On a side note, am I right in thinking the US has more stringent laws on pollutant levels than the EU? And as such certain vehicles (including most Euro-spec Diesels) can not be brought into the US?
With my GPS system that would no longer be an issue.
-
I think the pollution standards are about the same in the USA and EU.
There may have been a difference years ago. Unleaded Gasoline was introduced around 1975 along with catalytic converters, and many other pollution controls. I believe it was a decade later in Europe.
As far as diesels, the DPF was introduced in the USA and Europe almost at the same time. VW and Mercedes send some of their Diesel cars over here, but not all of them. Other companies choose not to bother with it.
Even so, we can buy a Diesel Golf, but not a Diesel Polo. And, the only choice in the Golf is the 2.0L "standard" Diesel, and we are unable to purchase the 1.6L Golf Blue Motion.
The Polo is one of those cars that VW chose not to send this way.
"Classic Diesels" have had problems. I have a 1981 Diesel VW (no turbo), and truthfully, it is not very clean burning. But, as standards changed, the manufactures didn't keep up with in in the US Market.
I think the problem lies in subtle differences in Safety laws between the USA and the EU. For example, UK cars would be problematic due to their right hand steering (although that is ok for "classics"). There is, however, a requirement that the speedometer read in MPH which might prevent other European cars from being imported.
There are special rollover restrictions on gas tanks which may not apply to European vehicles. So, the VW Rabbit/Caddies has an extra tank in the fuel tank ventilation system.
As far as the VW Blue Motion cars. I think at least part of the problem lies in shutting off the engine at stoplights. There is a law requiring the transmission to be shifted in to park before restarting the engine. Toyota applied for a special exception for the Hybrids, but it may not capture models such as the Blue Motion.
There also seems to be a belief that US drivers demand larger engines.
Perhaps there is some truth to that. My Classic Fiat 500 has a pretty puny engine. And, I have no doubt that when they were officially imported around 1960, the Fiat 500 Sports were better selling cars than the basic 479cc Fiat 500. But, the gasoline was only 30 cents a gallon then.
Vehicle advertising has often focused around horsepower, rather than fuel efficiency.
I suppose I find the difference between US and European fuel standards to be quite frustrating. Here are notes on the Smart Car (which is only available in the 999cc gasoline version in the USA).
European Union (EU) testing rates the 999 cc Smart at 4.7 L/100 km (60 mpg-imp; 50 mpg-US) for the gasoline model and 3.4 L/100 km (83 mpg-imp; 69 mpg-US) for the diesel.[citation needed] The U.S. Environmental Protection Agency (EPA) rates the vehicle at 36 mpg-US (6.5 L/100 km; 43 mpg-imp) combined.
It is possible that the efficiency rating systems are different. At least in the USA, one can hit the EPA ratings with a well tuned vehicle and careful driving.
One final note, tax structures may be different between the USA and Europe. Here it even varies from state to state.
In the USA, fuel tax is about 50 cents a gallon. With fuel prices now at about $4 per gallon, the tax is only a minor part of the fuel cost.
In Europe, the taxes have been much more substantial.
However, at least in Italy, the annual vehicle registration cost for Diesel vehicles is high. The fuel tax, however, is very low for Diesel, but high for Gasoline (at least 20 years ago).
Oregon is somewhat unique that we have a weight/mile tax. So, commercial vehicles pay no state fuel tax on Diesel, but pay a mileage tax. Pickups and small vehicles must, however, pay the fuel tax. Offroad vehicles can get tax-free diesel (which is colored red). Somehow they can keep all the tax rates separate which is something that would not be possible to do at least in Italy.
Anyway, Diesel now costs more than gasoline in many places. Less than half of the filling stations sell Diesel. So, the only incentive to use diesel is fuel efficiency.
-
Oh well, not so straight forward as simply changing the ECU map depending on the country then [:D] Thought that was a bit optimistic, but now I'm starting to see how different the two continents are!
In an ideal world I suppose the standards for pollution-control, safety, fuel and what-not would remain the same, whether you're in Europe, China India, the Americas or anywhere you care to name.
... but that maybe a little way off yet I guess [::)]
Am I right in thinking the recipe for gas' differs slightly from our Euro mix? I heard the stuff here is a bit more lively than the US stuff, but that may be an urban myth.
-
Re: w.r.t. 'allowing' more tailpipe NOx once out of urban centres:
http://www.ghgonline.org/othernox.htm
"Nitrogen oxides (NOx) act as indirect greenhouse gases by producing the tropospheric greenhouse gas 'ozone' via photochemical reactions in the atmosphere. ...
The breakdown of NOx gases gives rise to increased [abundance of hydroxyl radicals] and so helps to reduce the lifetimes of greenhouse gases like methane."
Potential for control
"Reducing transport emissions, in particular aviation, probably provides the most direct way to tackle NOx gases."
It describes NOx impact as 'not all bad' - so I guess it depends where the NOx is a) released and be) breaks-down.
The implication is Aviation accounts for a disproportionate share of NOx and is also growing rapidly. Again for my two-bit guess, I'd make the assumption that the particularly high-temperatures in jet engines is to blame for the large NOx formation. ... (?)