Better Bugs for Making Butanol

Comments

• 	butanol rhansing on 01/16/2008 at 12:26 PM
  Posts: 11 Avg Rating:	first, no fuel should be processed from corn and other food sources. the same with the cellulose from corn, since it is needed to be plowed under to keep the soil furtile. But a great use would be to use the tons of "fuel" trash, that we dump in the dumpyards. Rate this comment: (Reply)

• 	Patents Biofuelsimon on 01/17/2008 at 9:10 AM
  Posts: 1	I wonder how this fits with the technology that BP and DuPont are using to make butanol. Rate this comment: (Reply)

• 	the problem is the feedstock killian on 01/18/2008 at 4:48 PM
  Posts: 54 Avg Rating:	This is fairly neat work, since butanol is a better fuel than ethanol.  However, it shares ethanol's problem that photosynthesis is insufficiently efficient.  It would take too much land to replace gasoline with biobutanol, even if it could be made from high-per-acre feedstocks like switchgrass. Rate this comment: (Reply)

  • 	Re: the problem is the feedstock DJTal on 01/20/2008 at 5:54 AM
    Posts: 109 Avg Rating:	The scale of photosynthesis more than makes up for the low efficiency ...... think we've been here before killian ....... in any case other renewables can be used to catalyse the biofuel production system , which seems to be the route down which lots of renewable energy start up companies are going . Rate this comment: (Reply)

    • Re: the problem is the feedstock killian on 01/21/2008 at 11:16 AM

      Posts: 54 Avg Rating:

      When I do the calculations, it takes hundreds of thousands of square miles to produce enough cellulosic ethanol from switchgrass to make up for the poor efficiency of photosynthesis.  Is that what you mean by scale?  Are we going to turn 19% of the U.S. into ethanol production so we can drive?  That's scale alright. 420M people in 2050, 9300 VMT per person gives 3.9 trillion miles.  35 MPG for gasoline gives 112 billion gallons gasoline, or 154 billion gallons of E85 (adjusting for the energy content), requiring 131 billion gallons of ethanol.  Schmer et. al in PNAS recently reported switchgrass yields of 7100kg/ha and cellulosic ethanol at 0.38 L/kg which gives 2700 L/ha, or 185,000 gallons/mi^2.  That gives 710,000 mi^2, or 19% of the U.S.  Scale. Oh, and then there's freight... Rate this comment: (Reply)

      • Re: the problem is the feedstock DJTal on 01/25/2008 at 10:39 AM

        Posts: 109 Avg Rating:

        Interesting mathematics , but the equations don't take account of practical realites . Potentialy the entire growing area of the USA , including forestry , wetland and municiple land , can be used to produce biofuel since all crops produce residues and waste . All forestry produce can eventually be used to make biofuel when building timber and paper reaches the end of it's life . Plus your not taking into account the possibility of increasing productivity per acre , on the same sort of scale as food production was increased in the 20th centuary (seems such a long time ago) . Rate this comment: (Reply)

        • 	Re: the problem is the feedstock killian on 01/30/2008 at 4:29 AM
          Posts: 54 Avg Rating:	NREL has estimated the U.S. biomass potential of everything you mention as well as several you missed.  It is in the single digit percent range of the fossil fuel energy the U.S. uses each year. Rate this comment: (Reply)

          • 	Re: the problem is the feedstock DJTal on 01/30/2008 at 11:16 AM
            Posts: 109 Avg Rating:	20% is a pretty resonable estimate of the potential . Rate this comment: (Reply)

            • Re: the problem is the feedstock killian on 02/09/2008 at 2:14 PM

              Posts: 54 Avg Rating:

              I will take NREL's estimates over unattributed numbers any day. However, more importantly, two articles in Science just did calculations for greenhouse gas emissions from biofuels due to land use change, and the data really looks bad for most biofuels, unless they are made from waste.  For example, Fargione's paper said, "Our results show that converting native ecosystems to biofuel production results in large carbon debts. ... The carbon debts attributed to biofuels would not be repaid by the annual carbon repayments from biofuel production for decades or centuries." As a specific example, Searchinger's paper said, "This analysis has implications for other biofuels. Cellulosic ethanol could use wastes that do not trigger land use change. But if American corn fields of average yield were converted to switchgrass for ethanol, replacing that corn would still trigger emissions from land use change that would take 52 years to pay back and increase emissions over 30 years by 50%." This suggests that we had better restrict our ethanol feedstocks to waste products rather than growing crops specifically to make into ethanol. Rate this comment: (Reply)

• butanol quickerest on 05/12/2008 at 2:28 PM

  Posts: 1

  Imagine the entire wasted wood product from any disaster. Imagine all the waste we do not use every day. Imagine all the restaurants waste, imagine all the waste product from packing houses that charge very little for the waste food left behind after processing. Then imagine that this is not a one off oil replacement solution. This is just one solution that will have to be a multi layered system including transportation reform along with many alternative solutions to other power needs. This is a Great addition to any multi layered solution. How many layers?? Well consider all the desert land we have that can take on solar power, wind power, wave power hydro power, you name it we can manipulate our environment to optimize our power returns. Bullet trains. Common it is the best way to reduce emissions and increase connectivity reducing loss and spreading gains as the markets fluctuate across America. We will continue to use and pump oil but to simply start with adding more ethanol or butanol to our resource will make large differences in price and make a real step in the right direction. The other very important factor many also forget about is the large number of jobs we can create and economy boost that is created by building the infrastructure required for the changes needed to switch to a multi layer system. I do agree that there has to be a very big barrier between our food and fuel production or we will end up being reliant on others again for one of our two greatest needs; food or power. Rate this comment: (Reply)