[Sergi]

Hi all! Would anybody be interested in a conundrum that has been puzzling many non-chemistry experts for years? When DME is used in diesel engines, the insides of the fuel system (valves, filters, fuel lines) get stuffed with sticky deposits which is a real problem for fuel system's (and the engine's) operation. We have been trying to pinpoint the factors that promote this phenomenon, but despite involvement of some people who should be knowledgeable in these matters, this remains unsolved. I have heard some chemists say that DME would inevitably break up into monomers (?) when certain energy is applied to it (by heating, mechanically) and these would then inevitably polymerize, but this theory is somehow not popular among those working on the solution of the problem (they pursue the track of selecting special engine oils that would not react with DME, believing that the tiny amounts of lube oil that get into the fuel react with DME and form deposits), the effect of that being that we engineers keep suffering from this problem unabated.
There are many interesting things one can observe, for example the deposits seem to be forming almost exclusively where there is boiling, or maybe cavitation. For example, the suction mesh filter of the feed pump submerged in the fuel tank gets this stuff growing on the clean side of the mesh (downstream the restriction).
It seems to me we could try adding a polymerization inhibitor of some sort into DME fuel (which is DME with some fatty acid (I think) lubricity additive), just to see if it makes a difference. Would anybody know of a strong one to try? It unfortunately must have some specific qualities too in order to not destroy the fuel system's components, like it shouldn't be corrosive.
I would greatly appreciate any ideas on this subject! Thanks         

[PhDoc]

This brings back memories of some free advice I gave to a major LA company once. It took me 22 years to learn the knowledge. After giving them the free advice they implemented it and saved millions of dollars per year. That's when I stopped giving free advice when it comes to industrial applications. There are an abundance of consultants willing to answer this question for you at the rate of $100-150 per hour ($500 minimum contract).

Good luck!

[Sergi]

This brings back memories of some free advice I gave to a major LA company once. It took me 22 years to learn the knowledge. After giving them the free advice they implemented it and saved millions of dollars per year. That's when I stopped giving free advice when it comes to industrial applications. There are an abundance of consultants willing to answer this question for you at the rate of $100-150 per hour ($500 minimum contract).

Good luck!

Why didn't I think of that... Thanks LennoxT., will google up a good consultancy and try to get some professional help. Pity though that "experienced people" like you would rather see ordinary end customers of an industry getting ripped off by professionals for answering a trifling question than answering it in a forum like this one, when it doesn't constitute any work as such for you to do so and where you could make your input towards fair competition.     

[curiouscat]

Why didn't I think of that... Thanks LennoxT., will google up a good consultancy and try to get some professional help. Pity though that "experienced people" like you would rather see ordinary end customers of an industry getting ripped off by professionals for answering a trifling question than answering it in a forum like this one, when it doesn't constitute any work as such for you to do so and where you could make your input towards fair competition.   

How's it a trifling question if it has been "puzzling experts for years"? 

[Sergi]

How's it a trifling question if it has been "puzzling experts for years"? 
[/quote]

Of course this sounds illogical, but the explanation of that is simple: it's just that the wrong kind of experts are involved in trying to solve the problem. In other words, not the chemistry experts. ...But it may be true that the question isn't that trifling after all even for the chemists