Guest VooDoo Posted January 7, 2005 Share Posted January 7, 2005 I'm currently running methanol at temperatures below zero (-30°C). And when I went and checked the reservoir for the methanol I found some white residue on the metal (aluminium) and it had eaten through some plastic. Now is this normal methanol behaviour? The methanol is mixed with water. I won't go into detail about what the system is being used for. Link to comment Share on other sites More sharing options...
budullewraagh Posted January 7, 2005 Share Posted January 7, 2005 this is most likely a result of the reaction between aluminum and water, forming aluminum hydroxide. methanol's acid dissociation constant is really high so this probably has no effect whatsoever Link to comment Share on other sites More sharing options...
Martin Posted January 8, 2005 Share Posted January 8, 2005 this is most likely a result of the reaction between aluminum and water, forming aluminum hydroxide. methanol's acid dissociation constant is really high so this probably has no effect whatsoever many years ago a group I was in was studying options for synthetic fuels and we studied methanol and my memory is not too good of the details, but i remember someone telling me that some parts of automobile engines (or periferal like tank and fuel line or pump) would need to be redesigned with differnt material because methanol did SOMETHING. I curious now and would really like to know. What is there that gasoline doesnt corrode but that methanol does? I trust budu in general but I would like some online source for it, if possible. Link to comment Share on other sites More sharing options...
budullewraagh Posted January 8, 2005 Share Posted January 8, 2005 thing is, i can't see any reason for aluminum to react with methanol. think of it; the methanol lacks significant negativity. you'd never see the aluminum attack in a way leaving Al(3x bond)C-H you wouldn't see the aluminum attack in a way leaving Al(H3CO)3 either because the H3CO- anion is harder to form than the OH- anion with the Al replacing the H Link to comment Share on other sites More sharing options...
Silencer Posted January 8, 2005 Share Posted January 8, 2005 I don't see why the H wouldn't drop off from the O, wouldn't it be just like what happens with water? And I thought my teacher mentioned that being a donor proton when we were messing with 2-propanol and inks (different substances, but same OH bond). Maybe there were impurities in the water? Did you use tap water, VooDoo? Link to comment Share on other sites More sharing options...
budullewraagh Posted January 8, 2005 Share Posted January 8, 2005 exactly and thats why methanol wont react with aluminum Link to comment Share on other sites More sharing options...
Silencer Posted January 8, 2005 Share Posted January 8, 2005 What about the eaten-through plastic? Link to comment Share on other sites More sharing options...
budullewraagh Posted January 8, 2005 Share Posted January 8, 2005 depends on what sort of polymerized organic it is Link to comment Share on other sites More sharing options...
Technologist Posted January 12, 2005 Share Posted January 12, 2005 Aluminum hydroxide is a white solid. Anhydrous methanol is very corrosive to most metals I do believe, but in the presence of water methanol is much less corrosive. If chlorides are present methanol will corrode aluminum quickly, forming aluminum methylene chloride. I’m can’t recall its physicals properties. Did you use tap water? Link to comment Share on other sites More sharing options...
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