-----Original Message----- >From Michel:
> "cellulosic ethanol" or "advanced hydrous ethanol" seems very promising indeed! Can it be made easily from Gyre grown floating Sargassum do you think? I think that methanol could be made from this resource - using the water shift reaction From: Robin: >non-food-based "advanced hydrous ethanol" to be used in hybrid autos. Did you mean *plug-in* hybrids? >That combination can cut CO2 emission by 75% and make the USA >self-sufficient in transportation fuel. Nada. Plug-in hybrids can actually produce more - not less CO2, on average, in the USA compared to burning reformed hydrous ethanol as best I can tell assuming the available information is accurate. That is, until such time as we get a better mix of grid power (greater percentage wind or nuclear, or the breakthrough in non-carbon grid technology- and use far less coal). A comparison to burning mostly coal in the grid steam plant - at a Carnot eff of 45% (or less) followed by transmission line and transformer losses of 7% (or more) in order to charge batteries with in/out efficiency of 80% -- and obviously you are not gaining much from this effort - except making the pollution someone else's problem. Since coal is mostly carbon, nearly all of that emission is CO2. Nuclear, wind, solar, hydro etc are going to reduce that level by about one third - when figured on the average mix of resources across the country - and natural gas helps also making comparisons complex- but we burn mostly coal. ... i.e. Even when the average CO2 emission from the grid is reduced by the contribution of nuclear etc - you are still slightly better off (Less CO2 emitted) to burn reformed hydrous ethanol, due to the increased Carnot efficiency (50% or more in these various reports) and the fact that C2H5OH + H2O would release only ~one-third CO2 and ~two thirds steam (water). This converted diesel engine with fuel reformer is really a new class of steam engine. Now I would not blame you if you did not believe that Carnot could have been pushed that high in this type of engine. There have been only 3 reports AFAIK of this claim, and none of them from a National Lab, so there are reasons to doubt it - another one is that ethanol does not perform well when mixed with gasoline. However, there are no reports of anyone having tried hydrous reforming in a diesel - and failing. In short, this is exactly what Dr Chu and DoE should be focusing on - as we speak. If you drew up a flow chart for National Planning for 2009 - immediately discovering the reality behind this kind of claim for hydrous is about as high a priority as you can get, because the planting season for farmers has almost started, and if you want to maximize next year's supply you have to do that now. If that critical detail about the high Carnot of this fuel system in this type of engine is true however - combined with the better efficiency with the Prius type of hybrid drive train, you could indeed reduce CO2 by 75% (or more) for the same number of miles driven, over gasoline in a non-hybrid - and about 30% less CO2 compared to the plug-in hybrid using the current mix of grid power. It will be a long time before coal is supplanted for grid use due to its low cost, and that is why the emphasis on the Plug-in is misguided IMHO. You simply cannot phase-out coal plants when you encourage demand for electricity that is cheaply made from coal. Jones BTW - here is a revealing chart on the land use potential - for possibly doubling biofuel in the short term. Doable. And this does not include the ocean resources which could be enough on their own. http://4.bp.blogspot.com/_VyTCyizqrHs/SdZRmr2lvQI/AAAAAAAADS8/t_ySLnJ6bUU/s1 600-h/USlanduse.gif .
