From: toby@ccl.umist.ac.uk   
      
   Henry Spencer wrote:   
      
   > In article <9ibMb.3330$OA3.675888@newsfep2-win.server.ntli.net>,   
   > toby  wrote:   
   > >I read recently that researchers had developed a small device that reforms a   
   > >water methanol mixture to supply a hydrogen fuel cell. Would it make any   
   > >sense to use one of these to supply low molecular weight reaction mass to a   
   > >resistojet?   
   >   
   > Trouble is, you're throwing away a good fraction of the total mass,   
   > because the hydrogen is only a small portion of the input mass.  The waste   
   > counts against propellant consumption too.  For a rocket, you're almost   
   > always better off feeding everything you've got into the engine.   
   >   
   That's what I imagined being done.   
      
   I dont know what the reformer output is perhaps something like:   
      
   ch3oh + H2o --> co2 + 3h2 :combined molecular mass = 50   
      
   divided by 4 molecules  gives average value of 12.5   water is 18?   
      
   rt(18)/rt(12.5)=1.2 so maybe a 20% improvement over water?   
      
   12.5 might be a bit pessimistic as the water fraction may be lower but   
   the minimum can only be with no water which comes out at about 11 not a   
   huge difference.   
      
   I wonder if it would work with ethanol?   
      
   c2h5oh + h2o --> 2co + 4h2  [64/6 about 10.7]  about 30% better than   
   water.   
      
   Toby   
      
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