[Terrapreta] range fuels

[Sean K. Barry]

Hi Kelpie,

I don't know what the catalyst metal alloy is for "synthesis gas" to Ethanol-CH3CH2OH (EtOH).  "Syngas" to Methanol-CH3OH is easier, I guess.  I don't know what the liquid fuel that Fischer and Tropsch actually made was either?  Even though Methanol is easier to make (cheaper, simpler catalyst?) than Ethanol, I think Ethanol was chosen over Methanol, however, because EtOH combines with gasoline, it runs in existing internal combustion engines, it is already in the refueling infrastructure, it is the preferred octane booster in gasoline, it won't make you go blind by breathing it or touching it, and it has a higher BTU content than Methanol.

It should be interesting to note though, that transesterification of fats (rapeseed oil, soy bean oil, etc.) to make Methyl-Esters in bio-diesel requires 15% Methanol by volume of the bio-diesel produced.  In both cases, Methanol or Ethanol, there is a ~50 cent per gallon tax credit, as well, for production of alcohol fuel additives (in the USA, anyway).

There are problems with catalysts like you suggest, that the catalyst are rare metal alloys and such.  There are also problems with "poisoning" of catalysts.  One issue I read about was that it is important for instance to keep the Methane-CH4 content of the "syngas" low when trying to make Methanol.  Methane-CH4 bonds to the reaction sites on the catalyst, rendering it useless for making any more Methanol.  That is an example of what "poisoning" is.  When "poisoning" occurs and it usually does at some point, then a new catalyst surface has to be rotated in to the reactor somehow, and the "poisoned" catalyst surface has to be cleaned or refreshed.

All of the information about what the catalyst is, who developed that catalyst, how it's "poisoned", how it's refreshed, how the catalytic surfaces are handled, the temperatures, pressures, and the "syngas" composition, etc. are always proprietary information.  You will never hear any of the companies divulging any of that.  Regardless, when it comes to thermo-chemical conversion, gasification and FT are the likely normal routes, I think.  The themro-chemical conversion methods are for now, more expensive to do than biochemical conversion of sugars to make Ehtanol.  The details of the costs and the economies of scale, etc. of the processes are the trade secrets.

The selection of the products are usually driven primarily by what most consumers will buy and maybe secondarily by tax incentives.

Regards,

Sean K. Barry
Principal Engineer/Owner
Troposphere Energy, LLC
11170 142nd St. N.
Stillwater, MN 55082
(651) 351-0711 (Home/Fax)
(651) 285-0904 (Cell)
sean.barry at juno.com<mailto:sean.barry at juno.com>
  ----- Original Message ----- 
  From: Kelpie Wilson<mailto:kelpie at kelpiewilson.com> 
  To: Sean K. Barry<mailto:sean.barry at juno.com> ; Kevin Chisholm<mailto:kchisholm at ca.inter.net> 
  Cc: terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org> 
  Sent: Thursday, November 08, 2007 10:09 PM
  Subject: Re: [Terrapreta] range fuels


  Thanks for the info Sean.  I had always heard that Fischer Tropsch made diesel fuel. I guess it can make a variety of liquid fuels. These guys are smart to go for "cellulosic ethanol" as their first product since it has had so much publicity already. I can't understand why anyone would pursue the enzyme-fermentation route when this process is available. 
  One question I have though, is what the catalyst is. If it is a rare heavy metal like palladium, that would make it less economic. 

  -Kelpie

  At 03:44 PM 11/8/2007, Sean K. Barry wrote:

    Hi Kevin, Kelpie,
     
    I don't know exactly what Range Fuels is doing to make ethanol?  But I do know the basics of "thermal conversion process" which could do this.  If an "oxygen-blown" gasifier (pyrolysis reactor) is used (versus an "air-blown" gasifier), then the generated gas is called "synthesis gas" (H2, CO, CO2, CH4, H2O, trace O2 and others).  With an "air-blown" gasifier, the resulting gas is called "producer gas" (N2, H2, CO, CO2, CH4, H2O, trace O2 and others).  These gas mixtures are very similar, "producer gas" being like "synthesis gas" diluted with Nitrogen gas-N2.
     
    Air contains ~78% Nitrogen gas-N2 and ~19% Oxygen gas-O2.  Since N2 is chemically inert at pyrolysis temperatures, then the N2 passes through the reactor and dilutes the product gases of the reaction.  When pure oxygen is used instead of air as the oxidant, then the resulting "synthesis gas" has higher concentrations of the fuel gases Hydrogen gas-H2, and Carbon monoxide-CO, and actually a lower concentration of Methane-CH4.
     
    Back during World War II, two Swedish scientists, Dr. Fischer and Dr. Tropsch developed a method to convert "synthesis gas" into liquid fuels, like Methanol and Ethanol.  The German army harvest wood from the Black Forest and made liquid fuels to supply its vehicles using the process.  This was done in the back of truck! In a Fischer-Tropsch reaction "synthesis gas" is heated and injected into a pressurized chamber that has a metal surface (something like an Iron-Cobalt alloy) which "catalyzes" this gas-to-liquid conversion.
     
    There is a company, Rentech, which operates in California, Colorado, Montana, and Iowa that is using an FT reaction to make synthetic diesel (a liquid fuel) from "synthesis gas" that is got from gasification of western brown coal.   I would say, too, that this is the most like process that Range Fuels is using to convert lignin and cellulose from wood into ethanol.
     
    It is worth noting that when wood is pyrolyzed with pure oxygen, that the process can be continued either until only ash is left or the reactants can be moved out and new feedstock put in.  The primary soild reactant is CHARCOAL!  So, pyrolysis and gasification of wood/cellulose/liginin can have the co-products of gaseous fuels, liquid fuels, sensible heat, electricity, and charcoal.
     
    Regards,
     
    SKB
     
     




  Kelpie Wilson
  PO Box 1444 
  Cave Junction, OR 97523

  home office phone: 541-592-3083
  cell (used only when traveling) 213-925-1517

  For an archive of my writing and reviews of my novel Primal Tears, visit www.kelpiewilson.com


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