As was Hydrazine, normally a rocket fuel, used for a time in the '60s, when Nitromethane wasn't enough
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As was Hydrazine, normally a rocket fuel, used for a time in the '60s, when Nitromethane wasn't enoughBenzene was popular as a racing fuel for drag racing and dirt track until outlawed in the 60s.
I believe that in the book "The Jet Race" the author asserts that the Germans never really had a shortage of jet fuel, kerosene, diesel fuel. They just had a shortage of machines that could use that fuel. They had no trouble filling up U-boats right up to the last day of the war.
VW bugs were modified to start on gasoline and then run on kerosene.
German tanks were not diesel; Soviet tanks were. They could have switched their tanks over to diesel early in the war and and freed up high octane gasoline for the Luftwaffe.
Of course, jet aircraft could have used the kerosene but their shortage of high temperature engine materials was even worse than the fuel shortage. Jet engines with an MTBF of around 25 hours was about the best they could do.
Germany did spend years developing various such things, enabling for example many piston engine farm tractors to run on nearly anything that could burn, like wood etc. TheseThe most efficient, not best, and Perfect is the enemy of Good enough, is to use more of that Coal, as Coal.
Save on not needing those expensive Synth Fuel conversion plants.
Rather than taking the hit of 6+ tons of Coal to one ton of Liquid fuel, just use the existing Coal distribution network to power civilian and rear are Heer needs for moving things around.
They were using Horses, that was even more inefficient than Coal.
Let's compare Fuels
Diesel Engine efficiency is 38% for 1940s, Gasoline 26% for stuff that is roadbound.
Boilers and double acting cylinders like the Stanley Steamer or Sentinel Road Waggon, 9%
External Combustion just isn't that efficient. but is low tech, 1890s stuff.
Diesel has roughly 40% more BTU/lbs than Coal, depending on the grade, but it takes 4-8 tons of Coal to make 1 ton of synthetic oil, depending on the type of Coal, so you lose on using Synth plants, and not just of the fuel input stage.
Germany devoted over 4 million tons of Steel for the various Bergius hydrogenation or the Fischer-Tropsch process plants, and around 70,000 Workers at the start of operations at the start of the War.
From the USSBS
View attachment 720019
Bombing hurts.
The number of workers engaged in operating and maintaining the oil plants was 34,000 in June, 1938. The Karin Hall plan called for 6,600 additional operating personnel in mid-1939, to be increased to 66,000 by the second half of 1942.
In September, 1944, according to a statement by the Economic Group of the Fuel Industry, 20,000 persons were employed in crude production, 14,500 in crude refining, 89,200 in the synthetic industry, and 13,100 in coal tar distillation a total of 136,800. This estimate did not include miners, and probably omitted construction workers. Hence, some 200,000 workers were probably engaged in the production of oil in Germany. In the United States, about 270,000 persons were employed in drilling, producing, and refining oil in 1939, but this country's production then was more than twenty times the peak of 8,000,000 tons per year which the Germans attained shortly before the strategic bombers began to smash up their plants.
So lets avoid Synth Plants as much as possible
But lump Coal, isn't very efficient to store on vehicles, or to feed into the Boiler. So you can take the efficiency hit, and have a full time job of moving Coal into the Boiler.
This is fine for Civilian and Rear Area Army usage.
Buyt besides working the Coal thru Synthetic Plant, there is another way, but a bit more Technology than a Guy with a Shovel.
Grind it very finely, and add water.
Bingo- Coal Slurry. It can be pumped to a burner easily for Steam Engines
View attachment 720022
Coal Slurry looks like a poor Diesel, but the process is far simpler than hydrocracking Coal for Bergius process, that had pulverization as part of the process anyway.
I'm not saying Coal Slurry is awesome, but in areas where you don't need high speed diesels, you aren't wasting 4-8 tons of Coal to make one of Diesel of very pure nature(and you want some sulfur as to not wear out your mechanical injectors and pump)
Smoke is the sign of incomplete combustion, in Coal fired, or for that matter, Diesel applications. Coal slurry has much less problem in ash and incomplete combustion that solid Coal, so you gain back in efficiency what is lost in using water for the slurry
Now Actual Diesel Engines are more complex than a Boiler using a Coal Slurry Burner, in going thru mechanical injectors to each cylinder, and firing at the right moment, and the Slurry is more abrasive than 'Real' Diesel or Synthetic Diesel, so will be more wear.
Still could work for Trucks and Panzers.
The history of Aero-Diesel engines is not a happy one, so little relief for the Luftwaffe
There is a ray of sunshine in that cloud, Coal Slurry in Turbines. They already had low times before rebuild, so no change there
This is a move from the Coal Dust that they tried OTL to Slurry
USA during the Malaise Era coming out for other fuels, given the Shadow of the Arab Oil Embargo, did do research on Coal Slurry for vehicles stationary plants, and abandoned, as that threat receded.
They were using Horses, that was even more inefficient than Coal.
Boilers and double acting cylinders like the Stanley Steamer or Sentinel Road Waggon, 9%
External Combustion just isn't that efficient. but is low tech, 1890s stuff.
Grind it very finely, and add water.
Bingo- Coal Slurry. It can be pumped to a burner easily for Steam Engines
Coal Slurry looks like a poor Diesel, but the process is far simpler than hydrocracking Coal for Bergius process, that had pulverization as part of the process anyway.
I'm not saying Coal Slurry is awesome, but in areas where you don't need high speed diesels, you aren't wasting 4-8 tons of Coal to make one of Diesel of very pure nature(and you want some sulfur as to not wear out your mechanical injectors and pump)
Smoke is the sign of incomplete combustion, in Coal fired, or for that matter, Diesel applications. Coal slurry has much less problem in ash and incomplete combustion that solid Coal, so you gain back in efficiency what is lost in using water for the slurry
Now Actual Diesel Engines are more complex than a Boiler using a Coal Slurry Burner, in going thru mechanical injectors to each cylinder, and firing at the right moment, and the Slurry is more abrasive than 'Real' Diesel or Synthetic Diesel, so will be more wear.
Still could work for Trucks and Panzers.
The history of Aero-Diesel engines is not a happy one, so little relief for the Luftwaffe
There is a ray of sunshine in that cloud, Coal Slurry in Turbines. They already had low times before rebuild, so no change there
This is a move from the Coal Dust that they tried OTL to Slurry
USA during the Malaise Era coming out for other fuels, given the Shadow of the Arab Oil Embargo, did do research on Coal Slurry for vehicles stationary plants, and abandoned, as that threat receded.
Outside of dragsters and such, I don't think methanol ever became much used in racing outside the USA?
In the 1920s-30s there was a huge improvement in boilers. The ability to make power (steam) increased several fold for the same tonnage of boilers and the same foot print (square footage of boiler room)
- Switching from coal to oil
- Switching from fire tube to water tube boilers
- Switching from (typically triple) expansion steam engines to turbines
The German word Benzin strictly speaking means gasoline, not benzene.re Benzol, Benzene, Benzin, etc
...................... When the terms Benzol/Benzole/Benzene/Benzin are used relative to military aircraft fuels they are referring to a mix of benzine/toluene/xylene.
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Benzene and/or Benzol in some languages are specific to pure benzene, and are used in the scientific fields as such. But over the years, depending on which industry and/or country, the terms Benzol/Benzole/Benzin/etal may also be used to refer to any of several motor fuels containing a blend of the 'benzenes'.
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In the EU auto gas has a 35 v% limit on total aromatics and a 1 v% limit on benzene. No lead (TEL) allowed.Not sure if benzol really is pure benzene. Per the previously cited wiki page, it seems it was a trade name for a product produced from coal tar. So probably some kind of liquid containing mostly aromatics, of which likely a fairly high fraction was benzene.
Anyway, current automotive gas regulations typically limits benzene to < 1% due to the toxicity & cancer issue. Aromatics in general, while perhaps a bit offensive to current sensibilities wanting a clean-burning fuel (aromatics tend to produce quite a lot of soot), constitute about 20% of typical auto gas. In current 100LL aviation gasoline I understand toluene is the major aromatic fraction, and it has more aromatics than automotive gas due to the good rich octane rating. Non-benzene aromatics like toluene, (some isomers of) xylenes, and ethylbenzene also have somewhat more agreeable melting points.
The German word Benzin strictly speaking means gasoline, not benzene.
In German language benzene is called Benzol and toluene is called Toluol.
Today's 100LL aviation gasoline specification ASTM D910 allows some lead and has no limit on max aromatics or benzene content, although other specs (vaporization and freezing point) will be a limiting factor for aromatics content. Surprisingly there is no limit on carcinogenic benzene.
The cost of synthetic fuel is a bit of an irrelevance for Germany in war, and they have mountains of coal, so again
its not really a huge problem that you need lots of coal.
Another limit was the BTU content of the fuel specification.Today's 100LL aviation gasoline specification ASTM D910 allows some lead and has no limit on max aromatics or benzene content, although other specs (vaporization and freezing point) will be a limiting factor for aromatics content.
The C-85 engine in my Ercoupe was certified to run on 73 Octane. Despite that, there are people who do not want to use auto fuel in those engines and now you can't even find alcohol-free auto fuel that is less than 92 octane. 87 octane was "high octane" in 1940 and in fact the reason the DC-4 uses the R-2000 version of the R-1830 was because the airlines wanted to be assured that they would still get the same performance if they were forced to refuel at a field that only had the lower octane gasoline. When they were ferrying a Ju88 back to the US from N Africa they equipped it with some P-38 drop tanks and were assured that lower octane fuel was available at Ascension Island - but it was not. They were forced to use 100 octane fuel and almost did not make it the rest of the way across the Atlantic as a result.Depends on what you call "High octane".
Not that badSteam for road vehicles is just too bulky, I'm afraid. But a coal or wood powered gas generator is, I think, somewhat usable for civilian vehicles, and was indeed widely used.
Both Dust and Slurry were looked into. But with the embargo a thing of the past, not needed.IIRC the US railroads did quite a lot of investigation into using coal dust and/or slurry for diesel locomotives. But turned out it's just too abrasive for diesel engines. I suspect it would be the same issue if you try to burn coal dust or slurry in a gas turbine.
This helps provide some perspective:
(SOURCE: The Petroleum Handbook, SHELL, 1957, obviously my EXCEL)
View attachment 720274
The book Oil & War — How the Deadly Struggle for Fuel in World War II Meant Victory or Defeat by Robert Goralski and Russell W. Freeburg (first edition, William Morrow and Company, 1987; reprint, Marine Corps University Press, 2021) is an in-depth examination of the matter of oil during the war.
It can be downloaded for free from the Marine Corps University website.