What is cellulosic ethanol and how does it fit with green cars?
There is a lot of controversy surrounding biofuels. Various studies have shown that crop-based biofuels contribute to global warming more than they help prevent it, that ethanol is no better than gasoline, and that South East Asian rain forests are suffering for biofuels, to name just three. The most dramatic recent claim was that ethanol was the worst type of renewable energy. Read the story --> http://tinyurl.com/greencarsbiofuels
<<Various studies have shown that crop-based biofuels contribute to global warming more than they help prevent it, that ethanol is no better than gasoline>>
If produced properly crop-based biofuels are carbon neutral so they would not contribute global warming. Plant Cellulose is constructed from sugars. The idea is to use enzymes to break down cellulose into its constituent sugars and use them to feed yeasts or bacteria to produce alcohols. No Natural Gas or Coal would be needed to produce sugar from cellulose, sweet sorghum, sugar cane etc. Sweet Sorghum and Crops that produce large amounts of cellulose, switchgrass hemp etc, require little if any chemical additives and much less water than corn.
While ethanol does not have as much energy per gallon as butanol and many other biofuels it does burn much more completely than gasoline or diesel. Ethanol blended with gasoline provides additional oxygen that enables the gasoline in the blend to also burn more completely. That was the reason for MTBE, ethanol, etc to be blended as oxygenates with gasoline.
You cannot blend large amounts of ethanol with diesel as an oxygenate because that blend will no longer ignite on compression in a diesel engine, but butanol will work great because it has a different ctane rating.
Most of the oil based fuels burned in the USA are used in short daily commutes so most of it could be replaced with electric vehicles whose batteries could be charged with electricity currently wasted on our antiquated electric grid. The smartGRID COULD enable us to stop wasting huge amounts of excess electricity that we currently generate.
The US military currently uses large diesel engines to charge supercapacitors that supply electric motors for their large vehicles. Natural Gas could be mixed with a small amount of diesel fuel, it could be biodiesel, to fuel these engines. According to Boone Pickens the USA has large amounts of NG.
All of this is based of the Laws of Nature so I guess it is above the UNDERSTANDING of our LEADERS.
A synthetic diesel or jet fuel can be made by reacting natural gas and coal, but it has nothing to do with biofuel. This is a costly process and probably not econmic until $200 oil. It will come with peak oil. It does have an advantage in that it meets low sulfur limits.
I guess the whole idea behind going to cellulose to ethanol is that parts of a plant or grass or wood can be used and therefore not compete with the food crop. For example instead of using corn they could use the rest of the corn plant or the husk after the corn has been removed for food. That is this sort of ethanol can be made from crop waste and not the food part of the plant. Trouble is so far i dont know if it is efficient enought to be profitable, but looks like Bp has solved this problem.