Reciprocating Engines running Ethane 1

[Engimuneer]

With Ethane prices so ridiculously low and all the characteristics pointing to a good energy density & combustion properties, why are more vehicles not running this $0.30/gal fuel?

I'll be hooking up an Ethane K-bottle to a 4 cylinder GM Ecotec engine with natural gas fuel injectors this week. Wanted to save a few 'ah ha!' moments. I will not be taking emissions samples for this run.

 

[BrianPetersen]

Why would you or anyone restrict themselves to something that has such limited availability?

Gasoline can be gotten anywhere. Diesel can be gotten anywhere. Natural gas, a bit sketchier, but possible. Propane, same situation. Ethanol (blended as motor fuel), possible depending on where you live. But even electricity is more available than "ethane".

I know of NO place, anywhere, short of perhaps a gas processing plant itself, where one could fill up with "ethane".

 

[MikeHalloran]

Gasoline was once a worthless byproduct of lamp oil manufacture.

Start expanding the demand for ethane, and a demand for expanded distribution infrastructure, and the product price will rise to meet the demand.

If you can make do with today's infrastructure, you'll do well, for a while.
Go for it. ... and keep it quiet.

Oh. Let us know how many HP-hr you get out of a K bottle.
... and how many such bottles you can squeeze into your car.






Mike Halloran
Pembroke Pines, FL, USA

 

[dgallup]

Ethane is the second-largest component of natural gas, why bother to separate it out?

Will this ethane have any oil content? CNG has ~25 PPM of compressor oil which lubricates the injectors. Totally dry media like H2 will kill a CNG injector dead very quickly.

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[Lou Scannon]

Unless I'm mistaken the latest (NGI2) natural gas injectors from Bosch are engineered to tolerate totally oil-free fuel. This not the case for the first generation (EV1.3) injectors which are now basically obsolete. I believe Bosch even has a NGI2 service replacement for the EV1.3, but I could be wrong about that also.
If one has a guaranteed low-cost source of ethane in a form suitable for storage and use on-board a vehicle, it may be worth doing the engineering to run a single vehicle or small fleet on this fuel. But unless I'm missing something, there is no outlook for ethane to become a mainstream [so to speak] alternative fuel with sufficient availability to compete with, e.g., natural gas.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[j2bprometheus]

Enginumeer-

Ethane is more resistant to autoignition than gasoline ---- compare their RON and MON numbers.

So you may be able to advance the spark timing a bit and improve efficiency without getting into knock

On the other hand, compressor oil autoignites very easily. If there is much compressor oil in the ethane, knock might be an issue.

j2bprometheus

 

[Engimuneer]

My apologies for the delayed response. I had not received any notices.

The well head gas we are dealing with has a very high ethane content. Our device removed the Natural Gas Liquids, but leaves me with a blend of 50/50 CH4 & C2H6, enough to run a 150kW genset that provides power for the device. The calculated methane number for our mixture is around 53, which is well below the standard 65-80 required of most gensets. I will be attempting to alter the timing and possibly lowering the compression ratio for this blend.

The Bosch NGI-2 are just fine for running any of my fuel combinations thus far (H2, CH4, C2H6) and do not require lubrication. I only use MPFI on my test engines, an Impco style fueling system will be used for the final product.

 

[MikeHalloran]

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Mike Halloran
Pembroke Pines, FL, USA

 

[Lou Scannon]

I will be attempting to alter the timing and possibly lowering the compression ratio for this blend.

If you go down that road, I recommend you monitor turbine inlet temperature, at least initially, to make sure you're not exceeding mfr's maximum.
If you have the ability to adjust the lambda target with long-term accuracy, you might consider enleanment as an alternative or complementary strategy for regaining knock margin.
There are many variables which play a role in defining the lean limit for a given application, but I would expect an increased ethane/methane ratio in the fuel to allow leaner lambda operation for the same limiting conditions (engine out HC; COV of IMEP). Retarding timing, reducing compression ratio, and enleanment all have the effect of retarding combustion and increasing knock margin, but enleanment typically does not have a strong upward effect on exhaust temperature.
In order to make the same peak power, any of these measures will result in higher manifold pressure; so the engine's throttle margin will be reduced accordingly. Therefore I'd recommend you monitor throttle margin, speed stability, and load acceptance if you make any of these modifications, and ensure that the engine is still able to perform as required.
I also wouldn't be surprised to see a decrease in spark plug longevity with retarded timing or higher lambda; in terms of when the required voltage at the gap [as the spark plug wears over time] exceeds the ignition system's capability. However, ethane's superior ignitability relative to methane will tend to offset the effect of higher ignition pressure [i.e. due to the above-mentioned measures]; so the jury is out on this one until you try it (or a pertinent study comes to light).

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[turbocohen]

dgallup, Siemens/Continental Deka CNG and Bosch NGI2 are designed to survive running totslly dry. The materials we were messing with in the late 90's were not quite up to it but for over a decade now dry is doable. The injectors come prelubed and as long as they get a good lube to assist with "breakin" for the first half million or so cycles the next 300 million is not too tough.

 

[turbocohen]

As for ethane, it is good fuel for a genset and other stationary apps. If anything, in your application I would consider doping with an additive that prevents sulfur deposits inside the injectors. Just be sure not to use an oil based additive carrier, stick with alky free aero-solvent.

 

[dgallup]

turbocohen

Any clues or ideas of what makes a good prelube?

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[turbocohen]

dgallup, If the needle and seat are adequately hard and the guides are of a low friction design using unpolished gall resisting metals, a chlorinated graphite impregnated wax (non oil base sinter bronze lube) seemed to work well. Doping the injector with this after the initial run-in using stoddard solvent seemed to reduce guide and armature impact surface wear in our injectors and our competitors. More recent manufacturing (non abrasive deburring) and better material availability have negated the need for this though. When we were testing to 4x 120K mile durability using shot by shot injection this helped but in the real world 300 million cycles is enough to satisfy the market.