German fuel situation and what to improve on it, 2.0

[BarnOwlLover]

I already sort of hinted at that when I mentioned that Audi and Peugeot at Le Mans used to run a diesel fuel made by Shell that was made using natural gas refining byproducts though a Gas to Liquids process. Also, the current TotalEnergies Le Mans fuel is made though a process called Ethanol to Gasoline, whatever that means.

I'm pretty sure, though, that such things didn't exist in World War II. Though, interestingly, LPG and even wood burning fumes were used as fuel for cars and trucks in Germany and Italy at the time.

 

[z42]

I just remembered something from watching the 24 Hours of Le Mans last weekend, where Total makes the fuel used at Le Mans and the WEC out of waste materials from wine making (grape skins, wine stills, etc). The process is basically ethanol to gasoline. Also in the past, Audi and Peugeot used diesel fuel made from gas to liquids from waste materials from natural gas refining.

Granted, some (or probably a lot) of this tech wasn't really viable during World War II or was in its infancy, but could it have been useful in general during World War II for all sides?

There is a well-known(?) so-called Methanol-to-Gasoline process (MTG), developed IIRC by ExxonMobil in the 1970'ies. This is AFAIU what is used by this synthetic gasoline plant that Porsche is building in Chile (with the initial inputs being hydrogen made by electrolysis using renewable energy, and CO2 extracted from the atmosphere). Without looking further into this Total process, it wouldn't surprise me if it's some variation of the MTG process.

Diesel fuel made via a gas-to-liquids process in practice means Fischer-Tropsch (FT), invented in Germany in 1925. It was used by Germany during WWII. From wikipedia:

Being petroleum-poor but coal-rich, Germany used the process during World War II to produce ersatz (replacement) fuels. FT production accounted for an estimated 9% of German war production of fuels and 25% of the automobile fuel.

 

[z42]

What about natural gas as a fuel?

Once you get it into the engine, it's fine. The problem is how you get it there. Compressed gas storage is bulky and heavy, and cryogenic LNG technology AFAIU didn't really exist then (or at least, not ready for an industrial large-scale rollout). Similarly the dense gas pipeline networks you'll find in large parts of Europe, the USA and many other places today didn't exist back then either.

 

[tomo pauk]

Alcohol (ethanol) has some serious down sides as motor fuel.
It has around 1/2 the BTUs per gallon so if your truck has a 30 gallon tank you go 1/2 as far, yes you can make the tank bigger, or mount more than one tank. But that does mean your supply system need to move twice the tonnage of fuel. Better than no fuel but.....................

Seems like a high-power engine was using around 20% more of ethanol fuel than that of gasoline, while also making ~10% better power. That is with compression ratio being the same during the runs; fueling an engine with ethanol - in greater or lesser parts - enables increase of the CR, that can give better mileage and power.

German fuel situation was often 'no fuel'.

They used to make VW bugs that ran on Alcohol. However they had two fuel tanks, the main alcohol tank and a small tank (a gallon or so) of gasoline for starting in cold weather.
Think about that one. Needed a tank of starter fuel for cold weather......................in Brazil. Alcohol powered trucks on the Russian front?

Germans were operating a lot of trucks in the moderate climates, too (as well as vehicles and 2nd tier aircraft) . Every liter of fuel saved/not needed in France, Balkans, N. Africa or Germany proper is a liter of fuel available for the Eastern Front.

 

[z42]

I recently stumbled upon the BMW GT 101 ( BMW GT 101 - Wikipedia ). It was a gas turbine version of the BMW 003 jet engine, meant for tanks. Move over M1 Abrams and T-80, the Germans were planning this back in 1943!

As can be read from the wiki article, the motivation for the project was that although fuel economy of such early gas turbines was horrible, it could use more plentiful, cheaper and less refined fuel than the gasoline that the German tanks were running on. Similarly, the lower weight and large power output of the engine allowed it to carry around a lot more fuel than an equivalent gasoline powered tank.

Now, I don't think the lesson from this is that they should have switched the army (and why no the Navy too?) to gas turbines, that's clearly an unrealistic proposition. But it does underscore that producing high octane gasoline, be it from coal or petroleum, was (and is) an expensive proposition requiring a lot of infrastructure. I think the mistake they did, as I've mentioned earlier in this thread, was not going for 'dieselization' of the army.

 

[BarnOwlLover]

Not to go too far off topic, but wouldn't there be good modern high octane alternatives to leaded avgas?

 

[Shortround6]

Not to go too far off topic, but wouldn't there be good modern high octane alternatives to leaded avgas?

Maybe,
At what cost?
Are any of the chemicals more dangerous than lead?

Like
Toluene (C₆H₅CH₃) is a colorless liquid with a sweet, pungent odor. Exposure to toluene can cause eye and nose irritation, tiredness, confusion, euphoria, dizziness, headache, dilated pupils, tears, anxiety, muscle fatigue, insomnia, nerve damage, inflammation of the skin, and liver and kidney damage.

 

[marathag]

What about natural gas as a fuel?

In the 1980s, Propane gas was cheap , while gasoline was not. I converted a Chevy Truck to be dual fuel, Gasoline for starting and getting the engine warmed up, then switch to Propane with a solenoid valve to allow that to flow to a regulator, and then to a sprayer 'hat' over the Carter 4Bbl I had on that 350. Ran better with an MSD electronic box to adjust spark advance and curve to better work with propane. had a separate switch to stop the electric fuel pump to the carb.

It would not start well, or run that well on propane under 50 degrees or so with a cold engine. once the engine was warmed up it ran OK down to freezing or so

I would get 11mpg on gasoline, and 8-11 on propane. While used more propane, propane was almost half the cost, so made real sense.
By the '90s with the cheaper gasoline and far more expensive propane. wasn't worth doing, and sold the truck, with the Propane gear somewhere in one of my sheds.

Besides the lower cost, 2000 miles on Propane, that engine oil looked almost brand new, not dark like on Gasoline.
Natural Gas is about the same, but you need to compress it to get decent storage. Natural Gas has less than half the energy density of propane

 

[marathag]

Maybe,
At what cost?
Are any of the chemicals more dangerous than lead?

Like
Toluene (C₆H₅CH₃) is a colorless liquid with a sweet, pungent odor. Exposure to toluene can cause eye and nose irritation, tiredness, confusion, euphoria, dizziness, headache, dilated pupils, tears, anxiety, muscle fatigue, insomnia, nerve damage, inflammation of the skin, and liver and kidney damage.

TEL fouls spark plugs that the shorter chain Hydrocarbon fuel does not. Lead was cheap, and did have some bonus with lubricity.
Not worth the health risks, though

 

[z42]

Not to go too far off topic, but wouldn't there be good modern high octane alternatives to leaded avgas?

There is, a company called GAMI has created a fuel, G100UL, which is practically speaking a drop-in replacement for 100LL.

For a bit of background, ever since leaded auto gas phased out starting in the 1970'ies, and finally banned, there has been pressure to come up with an unleaded avgas. Not only from an environmental and public health standpoint, but also a security of supply and refinery issues. There is, AFAIU, a single plant on the planet producing TEL, if that plant burns to the ground or goes bankrupt will all piston powered aircraft be grounded? Also for the refineries 100LL is expensive, since it's a relatively low volume niche product, and after adding the TEL all pipes, tanks and whatever have to be cleaned before being used for other fuels so that the lead doesn't contaminate other products.

Anyway, still cheaper than coming up with an alternative has been kicking the can down the road. The FAA has been, under a variety of acronyms, trying to lead efforts to produce an unleaded 100LL replacement, with no results to speak of. The problem is that while 80% of the piston engine fleet could well run on a relatively low octane avgas that would be no challenge to produce (100LL without the lead is supposedly around 96 MON), the remaining 20% really need the octane and they use 80% of the fuel volume. At the same time avgas is nowadays such a small volume niche product that a two fuel solution wasn't seen as viable.

What GAMI came up with was per se nothing really exotic from a chemistry standpoint, all the ingredients are well known since decades. The trick is that instead of toluene for the aromatic component as 100LL largely uses, they use xylene (my guess would be the m-xylene isomer which has both high octane and suitable melting and boiling points). But for this reason the distillation curve looks slightly different than for 100LL so in theory it wasn't acceptable per spec. However, the difference is apparently small enough that after some further testing the FAA produced a blanket approval for the entire piston fleet.

As for what exactly G100UL contains hasn't AFAIU been released, but some fairly precise hints have been given, e.g. in
View: https://www.youtube.com/watch?v=6h9gYND3xFo

• aviation alkylate (a highly refined form of alkylate, containing a high proportion of iso-octane)
• xylenes (normal avgas uses toluene)
• an aromatic amine as octane booster (Probably N-methylaniline? Or m-toluidine? Or xylidine?)
• isopentane (for vapor pressure adjustment)
  

 

[z42]

Pulverizers are big and heavy and vibrate like crazy. They have thick heavy concrete foundations to help dampen the vibrations. Even then if you stand next to one you can feel it. I cannot imagine putting one in a ship.

I've been reading up on coal combustion technology, and I'm starting to come around to the position that my earlier suggestion to adopt pulverized coal combustion in ships is not viable.

Wikipedia mentions a 1929 US experiment with the SS Mercer, but while I found a newspaper notice about it online, there was no further details whether the pulverizer was onboard, or did they store previously powdered coal in the bunkers.

Anyway, since I haven't been able to find any further info about ships adopting pulverized coal, I conclude that it wasn't such a good idea in the end.

There were a few post war coal fired colliers built, some as late as the 1970'ies (or even 1980'ies). These ships used crushed coal and mechanical stoking (a crusher being much smaller than a pulverizer).

 

[z42]

Wikipedia mentions a 1929 US experiment with the SS Mercer, but while I found a newspaper notice about it online, there was no further details whether the pulverizer was onboard, or did they store previously powdered coal in the bunkers.

Anyway, since I haven't been able to find any further info about ships adopting pulverized coal, I conclude that it wasn't such a good idea in the end.

Info about the experiments on the Mercer on page 104 in Wayback Machine

If I understand it correctly from that description it does seem as if the pulverizer equipment was installed onboard the ship. A few other experiments with pulverized coal are also mentioned.

But the optimistic tone in which these experiments are described do stand in stark contrast with the fact that pulverized coal combustion on ships never really became a thing. Perhaps it was just the timing that was wrong, shipping was already in the process of conversion to oil at the time, and post war the shift to diesel engines put the final nail in the coffin of any dreams of a coal comeback?

There were a few post war coal fired colliers built, some as late as the 1970'ies (or even 1980'ies). These ships used crushed coal and mechanical stoking (a crusher being much smaller than a pulverizer).

Getting back to the issue of Germany's fuel issues before the war, and the prospects of using coal for ships, the above solution of crushed coal and mechanical stoking is something that was apparently quite widely adopted by steam locomotives, but I haven't been able to find info about using it on ships pre WWII. All the pictures I've seen of boiler rooms of coal fired ships during the era shows men with shovels.

And further, it seems coal bunkering for coal fired ships was very much a manual affair. "Coaling" on a warships was apparently a whole day of back breaking labor for the entire crew, using large canvas bags with coal that were emptied into the coal bunkers on the ship. It does sound strange that this wasn't mechanized. E.g. using the cranes on the collier to lift coal and empty it straight into chutes leading down into the bunkers.

Anyway, maybe the flexibility and ease of handling of oil was such an overwhelming advantage for a warship, but I suspect coal could be good enough for merchants and transport. Including inland shipping on barges along rivers and canals, to this day extensively used in central Europe.

 

[swampyankee]

Well, a pulverizer does add a significant maintenance load. I've read they are the piece of coal plant equipment at utility plants requiring the largest amount of work to maintain.

 

[z42]

Continuing my spelunking into the coal-oil transition for warships, in the UK in the runup to WWI there was a great debate wrt modernizing the RN to switch from coal to fuel oil. The energy density, ease of handling (a surprisingly large percentage of the crew on a coal powered warship were stokers and coal trimmers) were clearly seen as revolutionary, however security of supply was a big concern. Like Germany, the UK had mountains of coal but no indigenous petroleum reserves.

It was only with the government acquiring a controlling stake in the Anglo-Persian oil company Anglo-Persian Oil Company - Wikipedia in addition/instead of access to American (Standard Oil) and Dutch (Shell) oil, the coast was considered clear for a wholesale shift to an oil powered RN.

RN command of the seas was the lynchpin in ensuring that the oil from Anglo-Persian could be transported back to Britain also in a crisis, not only to fuel the RN itself but also to ensure the future prosperity of a Britain civil economy that was beginning to transition to oil powered vehicles.

In contrast it seems the Germans adopted petroleum energy without ensuring access to a supply beyond assuming a quick war would give them access to oil fields in the east. The synthetic fuels obviously helped, but although they were a technological tour de force, they were very expensive.

 

[EwenS]

Continuing my spelunking into the coal-oil transition for warships, in the UK in the runup to WWI there was a great debate wrt modernizing the RN to switch from coal to fuel oil. The energy density, ease of handling (a surprisingly large percentage of the crew on a coal powered warship were stokers and coal trimmers) were clearly seen as revolutionary, however security of supply was a big concern. Like Germany, the UK had mountains of coal but no indigenous petroleum reserves.

It was only with the government acquiring a controlling stake in the Anglo-Persian oil company Anglo-Persian Oil Company - Wikipedia in addition/instead of access to American (Standard Oil) and Dutch (Shell) oil, the coast was considered clear for a wholesale shift to an oil powered RN.

RN command of the seas was the lynchpin in ensuring that the oil from Anglo-Persian could be transported back to Britain also in a crisis, not only to fuel the RN itself but also to ensure the future prosperity of a Britain civil economy that was beginning to transition to oil powered vehicles.

In contrast it seems the Germans adopted petroleum energy without ensuring access to a supply beyond assuming a quick war would give them access to oil fields in the east. The synthetic fuels obviously helped, but although they were a technological tour de force, they were very expensive.

If you haven't found it already, you might be interested in this study about the RN's move from coal to oil covering the period 1898 to 1939

Chapter 4 deals with history of APOC and its early relationship with the RN.

https://kclpure.kcl.ac.uk/ws/portalfiles/portal/2932258/408161.pdf

 

[Denniss]

A coal-fired Tank/AFV is a bit tricky to use on the frontline. The best they could do was to adopt wood-gas and similar stuff for use at home and in training. This should probably have been adopted earlier but do not expect hindsight from a dictatorship.

 

[mack8]

Perhaps it may have been touched already, but regarding aviation fuel have i read correctly that they could make only 70 % C3 fuel compared to making B4 fuel, ie the C3 is more difficult, resource intensive etc. to do?

So if they just stick to making B4 fuel, they have 30% more fuel than whatever C3 quantity they made during the war, which must be a lot, hundreds of thousands or milions of tons more fuel?

Of course, that means the engines running on C3 would have be tailored for B4 instead and less power, BUT there is more fuel for training and combat operations. I guess they would have to focus on getting MW-50 to work as soo as possible, and focus on other internal improvements like superchargers etc. to at least partially compensate.

How do you think the likes of DB-601N and BMW-801C/D will be affected? The DB-601N got a new supercharger at some point as i understand, so that stays, but would the cylinder design change (but without the increased compression ratio) and increase rpm can still be adopted? As to the BMW-801, Tomo Pauk found that even the BMW-801C was running on C3, but was it like that from the start (other more widespread info say it used B4, perhaps initially?), or was it used because it was available and better for the engine? And the BMW-801D, i've read that initially it was planned as an internal/supercharger improvement, but still running on B4, so in this scenario they might adapt the same modfications, but presumably with less power on B4 than the OTL 801D.

The later war engines will have to be tailored for B4+ MW-50 boost to get more power, and they will simply have to accept any (further) decrease in reliability/life etc (compared to using C3).

 

[Deleted member 68059]

Perhaps it may have been touched already, but regarding aviation fuel have i read correctly that they could make only 70 % C3 fuel compared to making B4 fuel, ie the C3 is more difficult, resource intensive etc. to do?

So if they just stick to making B4 fuel, they have 30% more fuel than whatever C3 quantity they made during the war, which must be a lot, hundreds of thousands or milions of tons more fuel?

Of course, that means the engines running on C3 would have be tailored for B4 instead and less power, BUT there is more fuel for training and combat operations. I guess they would have to focus on getting MW-50 to work as soo as possible, and focus on other internal improvements like superchargers etc. to at least partially compensate.

How do you think the likes of DB-601N and BMW-801C/D will be affected? The DB-601N got a new supercharger at some point as i understand, so that stays, but would the cylinder design change (but without the increased compression ratio) and increase rpm can still be adopted? As to the BMW-801, Tomo Pauk found that even the BMW-801C was running on C3, but was it like that from the start (other more widespread info say it used B4, perhaps initially?), or was it used because it was available and better for the engine? And the BMW-801D, i've read that initially it was planned as an internal/supercharger improvement, but still running on B4, so in this scenario they might adapt the same modfications, but presumably with less power on B4 than the OTL 801D.

The later war engines will have to be tailored for B4+ MW-50 boost to get more power, and they will simply have to accept any (further) decrease in reliability/life etc (compared to using C3).

Keep in mind that the Methanol is made at the same plants making the synthetic aviation fuel. It was in fairly short supply later in the war, also the Synthetic plants also made just about all the stuff you need for Nitrogen & Ammonia based products, without which you cant (economically) make fertilisers or explosives. This was a major reason why bombing the synthetic plant sites literally stopped the entire German industrial/military machine in six months.

This is a major reason why you cant really get away from any solution other than more Hydrogenation plants, because if you don't have the Hydrogenation plant sites, you cant do anything at all in WW2 Germany because the products were needed for so many fundamental military/civil needs like food and explosives/propellant.

 

[z42]

A coal-fired Tank/AFV is a bit tricky to use on the frontline. The best they could do was to adopt wood-gas and similar stuff for use at home and in training. This should probably have been adopted earlier but do not expect hindsight from a dictatorship.

I think they should have gone for diesel power for the army. Significantly better fuel economy with attendant reduction in the logistics demand, less intensive refining required, and much less flammable providing a safety advantage.

For the home front, coal gasification with Otto engines or then steam (like the Sentinel trucks mentioned in this thread).

I think the points made by marathag earlier in this thread make sense. Synfuel, while it did work, was very capital intensive. Better to use coal directly where possible, and save the synfuels for applications where they are really needed (primarily military).

Wrt steam for road vehicles, a nice overview of various approaches at Steam Theory

Including a funny anecdote about valves for steam engines:

The great axiom of steam engine design is that there are two kinds of valves: poppet valves and those that leak.

A cautionary tale is in order before leaving, albeit temporarily, the subject of valves. That caution is about rotary valves. Rotary valves are like rotary engines; there is an initial and seductive attractiveness to them. Everyone thinks that they are the solution to all the world's steam problems. Without going into detail I will just state that they leak when they are cold and seize up when they are hot. This leaves a very short time period during which they actually work.

Perhaps Roy Fedden should have taken these lessons to heart.

 

[z42]

Keep in mind that the Methanol is made at the same plants making the synthetic aviation fuel. It was in fairly short supply later in the war, also the Synthetic plants also made just about all the stuff you need for Nitrogen & Ammonia based products, without which you cant (economically) make fertilisers or explosives. This was a major reason why bombing the synthetic plant sites literally stopped the entire German industrial/military machine in six months.

This is a major reason why you cant really get away from any solution other than more Hydrogenation plants, because if you don't have the Hydrogenation plant sites, you cant do anything at all in WW2 Germany because the products were needed for so many fundamental military/civil needs like food and explosives/propellant.

I think this gets cause and effect wrong. For fertilizer and explosives you need ammonia which you get from the Haber-Bosch process. For HB you need nitrogen, which you can distill from the atmosphere, and hydrogen. Nowadays hydrogen is produced via steam reforming of natural gas, back then it was coal gasification.

Coal hydrogenation via the Bergius process also requires a source of hydrogen (again, coal gasification), but other than that Bergius is not a step in the HB process or vice versa.

Now it made logistical sense to co-locate (as well as a more attractive bombing target) the HB plants with the Bergius plants and hydrogen plants, then as now hydrogen transportation and storage is very tricky. But they could have dispersed them, with one hydrogen production plant for the HB plant and another separate one for the Bergius plant.