Robert, a well educated and well respected Chem Eng., is again writing for the general public. Unfortunately, he, along with most of the authors of such articles, bundle "biofuels" together such that the reader after cruising through their words of wisdom still has little insight or understanding of the radical differences - pro or con - between the various biofuel sources. This actually makes his article totally moot.
Let's break it down:
Ethanol from any feedstock requires a 100% volume - high energy distillation process, is an incredibly caustic and toxic fuel, generates high volumes of undesirable emissions, the common feedstock (corn, switchgrass, ...) offer little CO2 processing, the fuel demonstrates an extreme evaporation rate, has a relatively low BTU density, is not now, nor will likely become cost viable even against petroleum in the near future. Yet, corn for ethanol production now occupies 48 million acres of prime U.S. farmland. Ethanol as we know it today should simply be discarded as a transportation fuel if it wasn't such a great and immediate excuse for why the U.S. is no longer shipping our historic 67% of total grain production to feed the populations of northern Africa, the Middle East, Pakistan, India, ... Seriously, wars can cost $B's per day, so not feeding a few hundred million people as the U.S. has been doing for decades, gives these semi-hostile nations something else to focus on - pending starvation - so they over-throw their own governments instead. I am OK with this strategy - especially since U.S. farmers are benefiting.
Biodiesel from 1st generation feedstock (soybeans, canola, safflower, ...) offers less than 100 gallons per acre of fuel - end of discussion - end of consideration.
Synthetic gasoline and synthetic diesel processing are x2-x4 the cost of biodiesel from 2nd generation feedstock for biodiesel and are not likely to come down in price significantly over the next decade. New technologies may make this solution economically viable at some point in the future.
Biodiesel from 2nd generation feedstock (jatropha and yellowhorn) offers between 400-1,400 gallons per acre per year, has a high BTU density - just under petroleum diesel, 9% distillation by volume, is rated non-toxic (1/10th as toxic as table salt), processes an amazing amount of CO2 to the point of rendering 2nd gen biodiesel from yellowhorn CO2 negative, has an extremely low evaporation rate, is cost effective today at $42 barrel equiv. against petroleum, contributes to dedesertification, provides human and animal foodstock and oils and provides biomass for baseload energy generation via the orchard clippings (automated harvesting and trimming). Considering current options and technologies, biodiesel from 2nd generation, high yield feedstock is our only environmentally friendly, economically viable, large scale and totally sustainable solution for petroleum replacement. The fact that it is a drop-in fuel saves literally $T's in infrastructure expenditures. There are 28M acres of yellowhorn orchards actively being planted in the U.S. today and the projected 200M acres of yellowhorn trees by 2020 worldwide will generate almost half of the world's 2009 petroleum production volume.
To take advantage of the benefits of 2nd generation feedstock sourced biodiesel, the U.S. must follow the migration of the rest of the industrialized nations and migrate to a diesel powered light fleet ASAP. Join the Migration - etcgreen.com U.S. Migration