US auto-emissions cleansed in urine-tech shower
Mercedes basks in blue-green-golden glow
German motor titan Mercedes Benz says it will be the first to introduce European-style "AdBlue" clean diesel technology to US consumers. AdBlue involves fitting cars with a tank of special urine-like liquid, which is used to clean the exhaust emissions.
In a statement last week, the company said:
The diesel engine has proved an attractive alternative [for] the USA in times of increasing fuel prices and growing sensitivity to the issue of CO2 emissions. In the land of large minivans, pickups and SUVs, and the given driving conditions characterised by steady cruising speeds on the highways and enormous overland distances, the diesel is able to show its advantages particularly well.
At the same time, American legislation sets very strict emission standards for diesel-powered vehicles. This is why Mercedes-Benz introduced the E 320 BlueTEC with its in-house BlueTEC technology in America first, and is now including a variant of this BlueTEC technology with AdBlue injection in its cross-Atlantic range. This innovative drive technology enables these large and powerful SUVs to meet the limits imposed by the US ...
Diesel engines, especially turbocharged ones, are quite green in many ways compared to petrol jobs. They are economical of fuel, and hence can have low CO2 emissions - which saves money on taxes as well as on buying fuel. For instance, even quite muscular turbodiesel 4x4s can escape London Mayor Ken Livingstone's swingeing new taxes against "gas guzzling Chelsea tractors", and the carbon-banded road taxes ease as well. The teeny, super-economical VW Polo BlueMotion turbodiesel is the lowest-CO2 car registered in the UK at the moment, just qualifying for the new sub-100g/km zero road tax band.
But diesels do emit comparatively large amounts of nitrogen oxide, which is nasty. Many US states, led by California, are imposing tough new nitrogen-oxide standards on new vehicles, and even tougher regs are on the horizon in Europe. Hence several manufacturers have begun making diesels as clean as they can - usually using the word "blue" in the branding for some reason.
Thus there is BlueMotion, BlueTEC etc. Early models wearing these badges have used different measures including filters, catalysts, engine modifications and whatnot. This latest "AdBlue" move involves fitting a tank full of "aqueous urea solution" which is squirted into the "exhaust tract" in very small amounts. This converts the nitrous oxide into ammonia, which in turn gets broken down into harmless nitrogen and water in a following catalytic unit.
Presumably the more obvious choice of "Golden" as a colour to represent this technology was deemed unsuitable. Too blue, perhaps. AdBlue is already used on large buses and trucks in Europe.
As a prelude to showering the US consumer with blue-green goodness, Mercedes showed off its new BlueTEC ML320 sports-utility Chelsea tractor at the New York auto show a couple of days ago. Its 28-litre tank of golden AdBlue is enough to go 28000km, seemingly, so Mercedes don't expect that customers will need to top it up themselves. This will be done by technicians during routine servicing.®
An alternative way to lower emissions in the UK
How about this for a radical new idea - stop town planners/councils/politicians etc. being so bloody car un-friendly. i.e. AC's Hertfordshire town would have less cars in a queue with their engines running at 0mph if there was either adequate parking or if the town is big enough a cheap park&ride bus.
The way I see it is this, modern cars have a newfangled bit of technology called a gearbox, now gearboxes allow the engine to provide different rotational speeds to the wheels at the same engine rpm output.
As an example from my 2.5 Turbo veg-oil burner auto-box :-
tick-over/0mph - 750rpm - Lots of wasted energy
0-15mph 1st gear - 2000rpm
15-30mph 2nd gear - 2000rpm
30mph 3rd gear - 2000rpm
65mph 4th+overdrive -2500rpm ** good speed / fuel usage ratio
95mph - 4000rpm red line bad speed / fuel usage ratio
Acceleration 0-30mph 3500rpm for 6sec and I might just get to the next set of lights before they go red.
There appears to be a pattern to the above data - the faster/smoother my journey is the less emissions per mile per unit time are being produced.
The more time I spend crawling along or accelerating the worse the pollution generated vs. duration of journey.
If the "planners" decided that removing obstructions on the roads that slow traffic un-necessarily, like bus lanes and poorly designed one-way systems with bad traffic light phasing that cause bottleneck jams (e.g. Surrey Quays), and instead adopted a traffic friendly approach (Milton Keynes) then more journeys would be completed in a shorter period of time with less overall pollution, less wasted time and less wasted fuel.
But from their point of view less fuel usage means less tax & it doesn't look as politically "green" as being anti-car.
Boffin Icon - well the Powers-that-be wouldn't understand the concept.
you all stink up the place
So glad I can pass the queues of cars pumping out their soot and fumes into each others crash-tested wheelie tombs, each day when I cycle to work.
It's not either-or. EGR is *very* well-known, and all manufacturers use it already. And they also know about its limits.
Re "lean-burn" engines, they have the problem that they lower some emissions but increase others (Nox). So not great there either. If a catalyst could shift the remaining emissions then fine, but it turns out that the exhaust output of a lean-burn engine makes it difficult to catalyse (translation: much more expensive cat needed). Eventually it might still come back, but only if emissions targets are unreachable except by spending more on the catalyst.
And lean-burn is 100% unconnected to the leaded/unleaded petrol issue. Whether leaded petrol was really as damaging as suggested isn't completely known AFAIK (especially compared to the LRP additives), but it has no bearing on the issues here, except insofar as leaded petrol is incompatible with catalysts.