a catalyst is something that remains unaltered at the end of one chemical reaction. Consider that it may be possible that the LPG acts as a catalyst in some hypothetical first stage and is then burned in a hypothetical second, third or fourth stage. obviously LPG in the presence of air and a flame isn't going to last long; maybe it lasts long enough.KiwiBacon wrote:
As already mentioned.
A catalyst is something that remains unaltered at the end.
I have a Weber barbeque, it does not use LPG. It does, however, make for a tasty roast. yes the LPG is burned, yes it releases heat, however consider it may also be possible that it contributes, however slightly, to the more complete combustion of the diesel fuel. There must be some kind of gestalt shenanigans going on; the way the LPG in added to the inlet air stream reduces the available oxygen, yet (at least for turbo, direct injection) diesels with LPG and no modification to injection volume make more power and less particulates.LPG is burnt, releasing the same amount of heat as your backyard BBQ can from the same fuel.
I like to think I have an open mind about it; I agree that it is extra fuel, but I also think there's slightly more to it than that. Find me a specialist petrochemical/organic industrial chemist who's done the numbers to prove there's no catalytic or other 2+2 = 5 shenanigans going on; every purveyor of these systems leads people to believe there is some catalyst-style action going on. Of course, plenty of people buy hiclones and felch fuel catalysts too; it could be all lies.Anyone who calls LPG a catalyst is well worth ignoring.
agreed, however there's still lots of sooty diesel in there, and the result is a greater degree less soot than can be accounted for by the differential in the carbon and hydrogen fractions of the two fuels as blended.The difference between diesel and lpg as fuel is the hydrogen content. LPG has much less carbon so doesn't show as black soot when reaching the limits of the fuel that can be burnt.
DPM is getting smaller and smaller which makes it much harder to detect, even with a highly precise and perfectly calibrated white hanky, however it is still a problem even in 'the latest engines'. There is still a need for catalytic converters and/or DPM filtering to keep particulate emissions 'low', even with the advances of common rail technology and massively increased fuel atomisation from better injector design and huge injection pressures. Agreed the latest engines have very low exhaust particulates FOR DIESEL engines, but they are still there. Since, however, this discussion is not about the latest engines (on which one would never dream of installing LPG fumigation), but about keeping oil clean, I'm at a loss to understand why you'd even mention 'the latest engines'; which run clean enough to have 20,000km plus service intervals.The cleanest diesels don't have high particulates. The latest engines exhaust meets the white hanky test.
I'm now going to increase my under-doona particulate emissions by eating something meaty for dinner. I do wish I could share the aroma with you all
PS if you are an petro/organic industrial chemist or chemical engineer who happens to have written a paper on Diesel/LPG burny burny, I'd like to have someone read it and explain it to me