Sunday, March 24, 2013

More on Acetic Acid and Ethanol





Several readers emailed me to ask if I was sure the yield of ethanol from acetic acid on a mass basis was only 75%.  I am actually sure it is less than 75%.  One mole of acetic acid will yield one mole of ethanol.  The molecular weight of acetic acid is 60 the molecular weight of ethanol is 46.  If the reactions are fully efficient and no reagent is lost the maximum mass yield of ethanol from acetic acid is 46 divide 60 or 76.6%.  With two reactions to get from acetic acid to ethanol each step will have a yield loss.  In the best of cases a 90% yield is pretty much the highest one can expect in an industrial reactor.  With two reactions one multiplies 76.6% by 90% twice and the optimistic industrial yield of ethanol from acetic acid is 62%.

Secretary Vilsack and his team at the USDA should perform a thorough and detailed analysis on the claims Zeachem has made.  If indeed the process should stop at the first step of making acetic acid then the USDA should significantly reduce the loan guarantee and simply tell Zeachem to demonstrate the biological production of acetic acid from cellulose and hemicellulose.  I am pretty sure the termite bugs will make a dilute solution of acetic acid and then Zeachem can sell vinegar to Whole Foods for $25 a bottle and the USDA may see five cents back on the dollar for the loan guarantees even if these loan guarantees are reduced to $50 million from almost a quarter billion.

I suggest we all write to our representatives in the US House as well as our Senators to apply $200 million of these savings to the fiscal cliff.  Spending money to make wine out of vinegar makes no sense when there is no money to keep the Whitehouse open to the public.  Even Marie Antoinette would not say if they have no wine let them drink vinegar.   Let’s see what Obama, Vilsack, Boxer, Feinstein, and Huffman do when I contact them.

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