[Terrapreta] range fuels

[mmbtupr at aol.com]

         from  Lewis L Smith, energy economist

As I recall, all gas-to-liquids processes [ GTL ] use FT [ an old 
technology ] plus proprietary catalysts [ new technology ].  There are 
actually several GTL processes which are commercially proven, and three 
GTL projects based on natural gas are under construction in Qatar. 
These processes produce one or more of what are called "middle 
distillate" when manufactured in an oil refinery, such as diesel, 
kerosene, naphtha, No. fuel oil and such like. [ There are also 
assorted specialty byproducts. ]  The input may be biogas, natural gas 
or a mixture thereof.

[ Further projects in that country have been put on hold, due to future 
electricity demand from luxury condominiums approved or under 
construction plus uncertainties about the geological nature and 
potential reserves of Qatar's largest gas field, which it shares with  
Iran ! ]

The oldest GTL technology is that of Shell, which has been making 
middle distillates  from natural gas in Malaysia for more than a 
decade. Shell has also bought a minority interest in CHORENS, the 
German inventor of a biogas process. A CHORENS plant under construction 
will supply biogass from wood and wood waste to a Shell plant which 
will specialize in making a major component of diesel by Shell's GTL 
process.

GTL would be a logical way to exploit a lot of "stranded" natural gas 
fields which are not economically accessible by pipeline and some of 
which are very large. Environmentally the products would still 
contribute to global warming, but the "stem to stern" impact would be 
considerably less than coal or oil. However, GTL products contain no 
sulphur.

However, there is a shortage of contractors who know how to build GTL 
plants, and their construction cost has shot up due to Chinese and 
Indian demand for cement, diesel, reinforcing bars and other inputs to 
the construction of capital-intensive projects.

The gasification of grasses grown on land not well suited to food crops 
plus GTL would also be a source of  energy environmentally better than 
refinery products, but again deployment is the bottleneck. There again 
are not enough people who know how to organize such projects and 
operate them or enough who know how to build them.

Cordially.  ###




-----Original Message-----
From: Kelpie Wilson <kelpie at kelpiewilson.com>
To: Sean K. Barry <sean.barry at juno.com>; Kevin Chisholm 
<kchisholm at ca.inter.net>
Cc: terrapreta at bioenergylists.org
Sent: Thu, Nov 8  11:10 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

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