A few days ago we talked about ethanol - about how we're stuck with corn and sugarcane based ethanol because of the huge investment that's been made in it and the desire the industry has to at least recoup that investment even if ethanol production is ultimately a bad thing for the planet and mankind.

I mentioned cellulosic ethanol. But I didn't really talk much about it, other than to say that it was the next generation of biofuel. So let's look at cellulosic ethanol...

Wikipedia has an acceptable explanation of cellulosic ethanol (and how it differs from the old ethanol produced from corn). Cellulosic ethanol is produced "from cellulose, the main component of wood, straw and much of the structure of plants." In other words, it's made from the stuff we don't eat.

The process for making from cellulosic ethanol is more complicated and more expensive than that for making ethanol from corn. The technology is new, and it's growing and changing. But cellulosic ethanol has a number of advantages over corn-based ethanol:

• The materials needed to make cellulosic ethanol are cheaper. In fact, it can be made from many waste products that might otherwise have little value.


• Crops useful in cellulosic ethanol production don't require land that is useful for food crops. So we could grow, for example, switchgrass for cellulosic ethanol production without disrupting corn or wheat production.


• According to TIME magazine, corn ethanol has a carbon debt of 93 years, meaning it would take nearly a century for ethanol, which does produce fewer greenhouse gases when burned than fossil fuels, to make up for the carbon released in the initial process of converting virgin landscape into cropland. But cellulosic ethanol using waste matter - like wood chips, or the leftover sections of corn stalks - or from perennial plants like switchgrass, effectively amount to free fuel, because they don't require clearing additional land. There's no carbon debt.


• TIME also reported that switchgrass yielded 540% more energy as a cellulosic ethanol than the amount of energy used to grow, harvest and process it. Corn produces just 25% more energy that it takes to produce it.

If ethanol is the way to go, it seems like cellulosic ethanol is by far the best choice (even if we are "stuck" with corn-based ethanol for the time being). So why and I so hesitant? Check back on January 2nd for that answer...


Photo courtesy of iStockphoto, Image# 5833062