DJ, I'm glad you brought that up!
Well, 1968 is a bit early, but on my first oil industry training course with Texaco in Canada in April 1975, Eric Glew was telling us how diesels are cleaner than petrol motors. I remonstrated that diesel exhaust is disgusting with clouds of black goop coming out.
They measured 'clean' by CO levels. And hydrocarbons. Neither did they include lead, which at the time was considered to be no problem though I suppose some concern was building because some studies had been underway into effects of lead on IQ - more related to acute sources such as lead paint in houses, water supplies and the like.
Well, we'd [wife and I] gone from London which was black with soot and muck, with the buildings dissolving from sulphurous acids, so I wasn't convinced that diesels were 'clean' in any meaningful sense.
Reincarnated as BP Oil International's Product Development Advisor for diesel and petrol in the late 1980s [after a stint as Technical Services Manager in Kiwiland - which involved all products from bitumen to gases, lubricants and a good dose of chemicals], my job was partly to figure out stuff to do with air pollution.
I got into a bit of an argument with the European Environmental Commission [nearly all of whom smoked, amusingly and incongruently - and wore glasses too; I didn't smoke or wear glasses, so I guess I noticed it being different] and BP wasn't fully aligned with my views either.
My argument was that diesel didn't belong in cities and if it was in cities, should be in the form of high quality diesel, designed primarily for commuting cars and cleanliness [where fuel quality is important and cost less important]. Of course the vehicle makers can include particle traps, but that wasn't our job.
Therefore, cetane number should be high [50 instead of the common 45 or 42] so engines start easily and fuel burns cleanly even when the engine is cold. Dirty-burning heavy and aromatic components should be dramatically reduced. Sulphur taken out [when engines cool, the Sulphur oxides reach the dew point and corrosion and lubricant depletion happen].
I didn't get it finished, but I invented a product [you are welcome to try making it if you are good at surfactant technology]:
Recipe is: 100 litres of diesel [distilled, high cetane, low sulphur, no gunk etc], 3% de-ionized water, 3% methanol, surfactant, maybe some diethyl ether and other stuff to lubricate fuel injectors and keep valves clean [though I suspect the water and methanol would keep valves clean].
The water makes it burn nicely, the methanol dissolves in the water and makes it neutrally buoyant [that's my trick], the surfactant makes a stable emulsion [which cunningly can be so fine that it's a clear liquid but I thought a milky emulsion might be a good marketing idea, not to mention cheaper since less of the expensive emulsifier would be needed. There would be a tax avoidance because the water could be added downstream of the tax take.
Our Sunbury diesel research guy thought the water would put out the fire. But the latent heat of vaporisation isn't very great compared with the fuel, so it burned nicely in test engines. Orimulsion, which is heavy crude oil mixed with 30% water and surfactant burns with only 3% energy loss, so 3% water wasn't much of a worry to me given the advantages.
Anyway, such a clean-burning fuel in cities would make a significant difference to air pollution, lubricant and engine life and customer enjoyment of their car, especially when starting and running cold in winter. The cost would be low compared with the advantages. Per litre, due to the water, it might be the same price as competing dirty diesel fuels [I forget now - the surfactant was horribly expensive].
The heavy haulage trucks starting in Spain and running to Sweden or Moscow could run on heavy, low cetane, high sulphur, muck. That would save them a lot of money and running at steady loads out in the countryside, the exhaust emissions would be irrelevant compared with the cost savings. Sulphurous fuels are fine with continuous hot running [acid plant turbines at fertilizer works - where terrorists can buy some good bomb making supplies - run on pure sulphur and the exhaust is used to make sulphuric acid which is used in the processing].
Trucks in Sweden [where it's cold much of the year] need different fuel from those in Spain. Wax freezes and the fuel filters block for a start. Fuel viscosity is crucial to get the right-sized drops in the injector spray.
Different refineries have different feedstocks.
My argument was that many diesel specifications were necessary for optimum performance and much human happiness and maximum profits.
The European bureaucrats wanted to have a single Europe-wide diesel specification.
The best answer is for fuel taxes to be neutralized so that people don't buy diesel cars in preference to petrol [gasoline for Americans] simply because of a tax advantage. Diesel engines inherently get more bang for the litre of fuel than petrol engines because they run at higher compression ratios and are therefore more thermodynamically efficient as well as diesel has higher density than petrol, so more calories per litre are squeezed into the fuel.
Petrol engines are limited by autoignition of the fuel, which is why high octane fuels are good for fuel efficiency - they allow higher compression ratio engines. But such fuel costs more.
Ah, that's just like the good old days.
Hey, you probably use my fuel [no lead 98 octane gasoline]. There's a lot of it around Europe now. I pushed for it and got it, but unfortunately, after I quit and came back to NZ, the refiners left out the other aspects of quality and got the high octane by including cheap carcinogenic aromatics. They did the same stupid thing here to the extent that elastomers dissolved and fuel pumps leaked. It's tough getting companies to understand the importance of quality.
Okay, back to your regular programme...
Mqurice
PS: I considered making the above diesel emulsion "BP Clear" as a milky emulsion from rapeseed or olive oil and using ethanol instead of methanol [which is death-dealing with only 20 ml], with lecithin as the emulsifier, some beta-carotene dye and some vitamins added.
It would be called "BP Beaujolais" and drivers could just have a little pipe leading to the cab in case they need refueling on the long haul to Stockholm from the South of France. As you know, the tax authorities in Sweden are rapacious on alcholic beverages, so this would be quite merchantable at the truck stops as a pick-me-up tonic as another profit centre. |
