[Gasification] Graphite Heat Exchangers for Producer Gas?

[linvent at aol.com]

	Not worth messing with in my opinion. 1. Any fixed surface will still coat, even at very low tar content.  2. At high temperature, C+CO, C+H2 reactions will eat up graphite, 3. if resin coated, will  not handle temperature and solvents in the gas.  


Sincerely,

Leland T. "Tom" Taylor
Thermogenics Inc. 



-----Original Message-----
From: Viswanathan KS <viswanathanks at gmail.com>
To: Discussion of biomass pyrolysis and gasification <gasification at lists.bioenergylists.org>
Sent: Sun, Jul 15, 2012 10:12 pm
Subject: Re: [Gasification] Graphite Heat Exchangers for Producer Gas?


Process for producing graphite tubes:


Quote
Synthetic graphite is manufactured from crude oil cokes and pitch. The pasty mixture is shaped into 
monolithic blocks or tubes. Tubes are extruded whereas blocks are usually vibration molded. The 
shape is then carbonized at 900ºC (1650 F)for a few hours and then fully graphitised at 2900ºC (5250 
F) for several days. The block or tubes are then impregnated with synthetic resin that is then 
polymerized to render them totally impervious to gases and fluids. 
The resulting material is fully corrosion resistant to most common acids (sulfuric acid, hydrochloric 
acid and of course industrial phosphoric acid) and has a very high thermal conductivity of around 80 
W/m.K for tubes or 140 W/m.K for blocks when totally graphitised. The tube wall is quite thick, 6 
mm (1/4”) and the individual tubes are 3 meters (10’) long.
Unquote


ksv

On Mon, Jul 16, 2012 at 9:27 AM, Bob Stuart <bobstuart at sasktel.net> wrote:

In the early days of graphite  fiber/graphite matrix brake disks on race cars, the ceramic coating would sometimes crack, allowing oxygen onto the hot graphite.  The result became known in the pits as "Designer Coal."


Bob




On 15-Jul-12, at 9:50 PM, Viswanathan KS wrote:


IMO the graphite tubes are not coated.


On Mon, Jul 16, 2012 at 8:45 AM, Bob Stuart <bobstuart at sasktel.net> wrote:
 
Would the coating that protects the graphite from oxidation not also work on copper?
 
 Bob

 
 On 15-Jul-12, at 8:10 PM, Tom Miles wrote:
 
 

 Graphite heat exchangers are now used on domestic condensing hot water boilers. (See SGL Group.) Heat transfer is reportedly 8 times that of stainless steel. Why not use them for cooling and condensing producer gas?
 
 
 
 Tom
 

 _______________________________________________
 Gasification mailing list
 
 to Send a Message to the list, use the email address
 Gasification at bioenergylists.org
 
 to UNSUBSCRIBE or Change your List Settings use the web page
 http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org
 
 for more Gasifiers,  News and Information see our web site:
 http://gasifiers.bioenergylists.org/
 

 
 
 _______________________________________________
 Gasification mailing list
 
 to Send a Message to the list, use the email address
 Gasification at bioenergylists.org
 
 to UNSUBSCRIBE or Change your List Settings use the web page
 http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org
 
 for more Gasifiers,  News and Information see our web site:
 http://gasifiers.bioenergylists.org/
 



_______________________________________________
Gasification mailing list


to Send a Message to the list, use the email address
Gasification at bioenergylists.org


to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org


for more Gasifiers,  News and Information see our web site:
http://gasifiers.bioenergylists.org/
 




_______________________________________________
Gasification mailing list

to Send a Message to the list, use the email address
Gasification at bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org

for more Gasifiers,  News and Information see our web site:
http://gasifiers.bioenergylists.org/




 
_______________________________________________
Gasification mailing list

to Send a Message to the list, use the email address
Gasification at bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org

for more Gasifiers,  News and Information see our web site:
http://gasifiers.bioenergylists.org/

 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/gasification_lists.bioenergylists.org/attachments/20120716/0dd01103/attachment.html>