01-02-2012 01:02 PM
Ladies and Gents, got a fuel analysis 20% C1, 20% C2, 33% C3, 17% C4. What is your opinion to try a propane conversion of the engine. Is this still possible with the 3512B @ 1400 rpm? Looking forward to your opinion.
01-19-2012 01:33 AM
This fuel sample is very poor fuel for a Cat gas engine. This fuel is probably not usable in an engine. The G3500B engines do not have propane conversions yet as far as I know. It might be a while, if ever, before a propane configuration is available.
02-01-2012 02:56 PM
The high molar fraction of over 25% with C4, C5, C6, makes this a difficult fuel to operate an internal combustion 4 stroke engine without serious risk of detonation/pre-ignition (compression ignition starting a separate flame front) even at naturally aspirated (NA) ratings or less than 50% ratings.
My question to whoever provided the fuel sample is: "under what conditions was the fuel sample taken?" I ask because the C4, C5, & C6 could very well be liquids which would condense or drop out of solution from the gas if the gas is allowed to be lowered in pressure to atmospheric pressure (~1 bar) or at least down to 2 bar and lowering the temperature to standard conditions of 25DegC. Then removing these C4, C5, & C6 NGL's (Natural Gas Liquids) which usually have very high market value for lighter fluids, etc would dramatically shift the Caterpillar MN from a negative value to about 30. The G3512 LE (Not the G3512B LE with two stage intercooler & compressor bypass boost control) with a propane valve and jet conversion kit may be able to provide a rating but would require removal of at least the C5 and C6 gases.
What may be a better engine choice is the best running G3500B LE: the G3512B LE at 1400 rpm provides full rating at 1200 meters and 38DegC air assuming you can drop the condensate gases of C6 Hexane, C5 isoPentane, and C5 norPentane out of the Methan Zapadno-Tarkosalinskoe fuel gas. That action takes the fuel Cat MN up to 31. (When one works with GERP trying the various engines with fuels at HD5 propane and hotter, one finds the G3512B LE has no derate while others have some derate at many operating conditions.)
Here is the GERP performance with the assumption of removing the C5iso, C5nor, and the C6. Without knowing more about the site and application we cannot offer any more of an estimate for you.
If the C6, C5iso and C5nor cannot be easily condensed out by dropping the pressure to about atmospheric pressure and standard temp of 25DegC then there may need to be some other fuel treatment to get the engine to run without issue.
11-17-2012 11:49 PM
Cat does not offer a propane fuel configuration for the G3500B gas engine.
As for converting earlier G3500 engines to use propane, I don't believe Cat supports this either. I haven't had any questions about a conversion like this in a long time so I don't fully remember all the facts, but I don't find a performance data sheet for the G3500 using propane fuel.