Biofuels have been widely touted as a preferable alternative to petroleum. However, the most commonly and viably applied method for the production of ethanol typically involves the diversion of material from the food supply to the manufacture of ethanol. This rightfully strikes many as a rather perverse way to solve an energy problem.
However, new developments underway in biofuels technology are explored as the cover story in the July issue of Scientific American magazine just now hitting the news stands.
Ethanol production has largely been derived from corn, in which the necessary sugars form a sufficient portion of the raw material input, and from which the sugars are easily obtained.
This “first-generation” biofuel approach is understood to not represent a real alternative to fossil fuels: The world would exhaust its agricultural capacity to grow crops long before replacing petroleum. And people do still need to eat.
The real promise continues to lie in the arena of “second-generation” biofuels: In these, the sugars are derived from a process that converts cellulose — the fibrous matter that comprises the greater portion by weight of most plant material — into ethanol.
Cellulose provides the structure and strength for plants, and nature has designed a very tough nut to crack, chemically speaking. What has eluded us so far, but precisely where we’re currently witnessing genuine progress, has been a way to break down cellulose less expensively and less energy intensively.
And herein lies the real promise of biofuels: We can use any manner of agricultural and municipal plant waste, and we can look beyond yard trimmings and cornstalks to crops such as switchgrass that efficiently convert sunlight into biomass and are less water intensive and soil-depleting.
Set aside the matter of greenhouse gases and global warming altogether. By the supply numbers alone — how much energy is contained within the oil known or believed to ground, compared to how much energy the world will need — we need to first supplement, then replace petroleum as an energy source.
And we’re inching ever closer to a serious biofuel technology breakthrough that will allow us to turn away from oil and towards the soil in meeting some of our energy needs.