Aviation Fuels

[RLBH]

Basically if it was liquid and flammable, you could run it through a turbine engine.

Not necessarily even liquid, just fluid - there's a fixed gas turbine powerplant in the Outer Hebrides that runs on peat, and I believe that pulverised coal has been done too. Remarkably tolerant things, turbine engines.

[rickshaw]

I think you'll find that they pulverise and then liquefy the coal, first before using it as fuel (usually mixing it in a slurry with Dieso).  In the case of the Peat, they'd liquefy it beforehand and I assume mix it with again, something like Dieso.   I don't think they feed it into the turbine in a solid form which is what you implied.

[rallymodeller]

I think you'll find that they pulverise and then liquefy the coal, first before using it as fuel (usually mixing it in a slurry with Dieso).  In the case of the Peat, they'd liquefy it beforehand and I assume mix it with again, something like Dieso.   I don't think they feed it into the turbine in a solid form which is what you implied.

Union Pacific built this monster back in the 50s:



and it had a GE turbine that did indeed run on pulverized, powdered coal. However, they found that the powdred coal was so corrosive that it was eating the turbine blades, and the project was abandoned.

[royabulgaf]

Didn't the B&O or one of the other eastern RRs build a similar engine"

[jcf]

I think you'll find that they pulverise and then liquefy the coal, first before using it as fuel (usually mixing it in a slurry with Dieso).  In the case of the Peat, they'd liquefy it beforehand and I assume mix it with again, something like Dieso.   I don't think they feed it into the turbine in a solid form which is what you implied.

Union Pacific built this monster back in the 50s:



and it had a GE turbine that did indeed run on pulverized, powdered coal. However, they found that the powdred coal was so corrosive that it was eating the turbine blades, and the project was abandoned.

ummm ... corrosive or abrasive?
Corrosive, which implies a chemical process, doesn't sound likely.

[rallymodeller]

I think you'll find that they pulverise and then liquefy the coal, first before using it as fuel (usually mixing it in a slurry with Dieso).  In the case of the Peat, they'd liquefy it beforehand and I assume mix it with again, something like Dieso.   I don't think they feed it into the turbine in a solid form which is what you implied.

Union Pacific built this monster back in the 50s:



and it had a GE turbine that did indeed run on pulverized, powdered coal. However, they found that the powdred coal was so corrosive that it was eating the turbine blades, and the project was abandoned.

ummm ... corrosive or abrasive?
Corrosive, which implies a chemical process, doesn't sound likely.

My mistake, blade erosion would have been the correct term. That and soot buildup. Wiki article on UP Gas Turbine Electric Locomotives

[NARSES2]

I think you'll find that they pulverise and then liquefy the coal, first before using it as fuel

Yup we used pulverised coal as an injectent to blast furnaces in the steel industry. The pulverising plant was quite a large beasty and yes it was mixed to form a slurry before injection. One problem during the development phase was that "powdered" coal like most powders can be extremely explosive given the right circumstances. One or two dry bulk carriers have found that out the hard way even when carrying flour.

[rickshaw]

I think you'll find that they pulverise and then liquefy the coal, first before using it as fuel

Yup we used pulverised coal as an injectent to blast furnaces in the steel industry. The pulverising plant was quite a large beasty and yes it was mixed to form a slurry before injection. One problem during the development phase was that "powdered" coal like most powders can be extremely explosive given the right circumstances. One or two dry bulk carriers have found that out the hard way even when carrying flour.

Yep.  Fuel-Air Explosives by another name.  Its why we pump nitrogen into Wheat silos downunder.

[dogsbody]

The powerhouse, at the oilsand plant where I work, uses powdered coke as a boiler fuel. The coke comes from the coking towers of the on-site  upgrader.



Chris

[NARSES2]

The powerhouse, at the oilsand plant where I work, uses powdered coke as a boiler fuel. The coke comes from the coking towers of the on-site  upgrader.

Chris

Interesting "breeze and smalls" as we used to call them. We sintered them with iron ore and limestone. Still I suppose it's all similar to the coal/coke briquettes that were used back in the 50's.

Going back to the origional subject didn't the Germans develope an onboard system for using coal/lignite as an aviation fuel in WWII ? I think they actually tested it and it worked. I'll try and find where I saw the article.

[Hobbes]

Was the work on that onboard system anything to do with the Lippisch P.13a?

[Rheged]

I think you'll find that they pulverise and then liquefy the coal, first before using it as fuel

Yup we used pulverised coal as an injectent to blast furnaces in the steel industry. The pulverising plant was quite a large beasty and yes it was mixed to form a slurry before injection. One problem during the development phase was that "powdered" coal like most powders can be extremely explosive given the right circumstances. One or two dry bulk carriers have found that out the hard way even when carrying flour.

Yep.  Fuel-Air Explosives by another name.  Its why we pump nitrogen into Wheat silos downunder.

Even CUSTARD POWDER  will explode given the right conditions!   Herewith the unlikely but accurate  tale of:-

The Great Custard Explosion of 1904

  In 1904, a  workman in a biscuit factory in Carlisle slipped off into a store room for a quiet ciggie. The store room was full of cornflour based custard powder for producing custard creams.  He lit a match and the resultant "custard explosion"  stunned him,  blew out a window which landed in the street below and (in the words of the local newspaper) severely inconvenienced a carter and his horse who were passing by.

[NARSES2]

Was the work on that onboard system anything to do with the Lippisch P.13a?

I don't think so Harro. The piece I read was more about its use in multi engined types as a replacement for standard aviation fuel

[sagallacci]

I seem to recall that the Lippisch system was a bit like a hybrid rocket motor. An array of solid fuel elements had air pass through it for burn to create thrust. Looked kind of iffy for endurance or high impulse.
Modern diesels are getting closer to petrol engines for performance/weight, especially for smaller units, and diesel has a better energy density than petrol, and a mixed turbine/diesel machine could eat common fuel. However, turbines still give the best power/weight, though diesels might(?) still have the best power/fuel ratio.

[Hobbes]

Modern diesels are getting closer to petrol engines for performance/weight, especially for smaller units, and diesel has a better energy density than petrol, and a mixed turbine/diesel machine could eat common fuel. However, turbines still give the best power/weight, though diesels might(?) still have the best power/fuel ratio.

Hence the Napier Nomad. At the time, it was the most fuel-efficient aircraft engine ever, iirc.