<div dir="ltr"> An Open call for a very Merry New Season to all !! We are Looking to Buy/Build A100+ KWelec We have Beetle Kill Pine 12-15% MC Whats the optimum chip size?/range Lookin @ the Liamet Screw Chipper Many are Hope,n To Realize this Dream As we still are waste,n to much Fiber In BC Canada The diesel price?? or Propane The Utilization&Job creation Thank You for any Direction We see Indepth Tech & Advice WHipkin Merry&aHappy <div>
<br></div><div><br></div><div><br><div><br></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Dec 20, 2013 at 11:00 AM, <span dir="ltr"><<a href="mailto:gasification-request@lists.bioenergylists.org" target="_blank">gasification-request@lists.bioenergylists.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Send Gasification mailing list submissions to<br>
<a href="mailto:gasification@lists.bioenergylists.org">gasification@lists.bioenergylists.org</a><br>
<br>
To subscribe or unsubscribe via the World Wide Web, visit<br>
<a href="http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org</a><br>
<br>
or, via email, send a message with subject or body 'help' to<br>
<a href="mailto:gasification-request@lists.bioenergylists.org">gasification-request@lists.bioenergylists.org</a><br>
<br>
You can reach the person managing the list at<br>
<a href="mailto:gasification-owner@lists.bioenergylists.org">gasification-owner@lists.bioenergylists.org</a><br>
<br>
When replying, please edit your Subject line so it is more specific<br>
than "Re: Contents of Gasification digest..."<br>
<br>
<br>
Today's Topics:<br>
<br>
1. Re: raising H2 concentration in downdraft gasification<br>
(Rex Zietsman)<br>
2. Re: raising H2 concentration in downdraftgasification (Kevin)<br>
<br>
<br>
----------------------------------------------------------------------<br>
<br>
Message: 1<br>
Date: Fri, 20 Dec 2013 09:32:32 +0200<br>
From: "Rex Zietsman" <<a href="mailto:rex@whitfieldfarm.co.za">rex@whitfieldfarm.co.za</a>><br>
To: <<a href="mailto:gasification@lists.bioenergylists.org">gasification@lists.bioenergylists.org</a>><br>
Subject: Re: [Gasification] raising H2 concentration in downdraft<br>
gasification<br>
Message-ID: <007001cefd55$a5f3f840$f1dbe8c0$@<a href="http://whitfieldfarm.co.za" target="_blank">whitfieldfarm.co.za</a>><br>
Content-Type: text/plain; charset="us-ascii"<br>
<br>
Hi All,<br>
<br>
The deafening silence on this post is quite interesting. At the very least I<br>
would have thought that someone would have suggested adding steam to the<br>
reduction zone. What about a charcoal gasifier with steam addition?<br>
<br>
Any comments on a 1.6MW/2MW thermal gasifier?<br>
<br>
Kind regards<br>
Rex<br>
<br>
-----Original Message-----<br>
From: Rex Zietsman [mailto:<a href="mailto:rex@whitfieldfarm.co.za">rex@whitfieldfarm.co.za</a>]<br>
Sent: 16 December 2013 09:57 AM<br>
Subject: raising H2 concentration in downdraft gasification<br>
<br>
Hi All,<br>
<br>
We are looking at a system that will hydrotreat bio oils from pyrolysis,<br>
catalytic cracking and vegetable oil. For this we need in the region of 30kg<br>
hydrogen/ton oil. At small scale ie 1 ton oil/hour, this works out at, you<br>
guessed it, 30kg of hydrogen/hour. As this is a small amount in the overall<br>
scheme of things, we are looking at gasifying wood chips and to recover the<br>
hydrogen using pressure swing absorption. What I would like to know is<br>
whether we can increase the H2 concentration in syngas by tweaking the<br>
gasifier. Clearly we can look at the water gas shift reaction but, as the<br>
syngas has to be cooled, washed, pressurised and reheated, it is quite an<br>
additional investment for the scale we are looking at. If we could simply up<br>
the H2 content, we would go straight from washing to PSA. Residual gas would<br>
be piped to a diesel generator where CO and the like will be combusted prior<br>
to exhaust to atmosphere.<br>
<br>
For easy mental arithmetic, let us assume a 33% H2 concentration in dry<br>
syngas. 30kg/hour of H2 is 15kmol/hour or 15/0.33 = 45kmol/hour of syngas. A<br>
kmol of gas has a volume of 22.4 Nm3. So, to get 30kg/hour requires 22.4 x<br>
45 = 1000 Nm3 syngas/hour (mental arithmetic here, go with the flow).<br>
Assuming an 80% PSA recovery this means that we need 1250Nm3/hour of syngas.<br>
Not a bad sized downdraft gasifier! Assuming 6MJ/Nm3, this is around a 2MW<br>
thermal unit. If we can get the H2 concentration up to say 40%, then the<br>
syngas requirement would be 37.5kmol/hour or 37.5/45 x 1250 = roughly 80% of<br>
1250 or roughly 1000 Nm3 syngas/hour. This reduces the size of gasifier to<br>
1.6MW thermal and more sensible in size.<br>
<br>
<br>
---<br>
This email is free from viruses and malware because avast! Antivirus protection is active.<br>
<a href="http://www.avast.com" target="_blank">http://www.avast.com</a><br>
<br>
<br>
<br>
<br>
------------------------------<br>
<br>
Message: 2<br>
Date: Fri, 20 Dec 2013 04:49:02 -0400<br>
From: "Kevin" <<a href="mailto:kchisholm@ca.inter.net">kchisholm@ca.inter.net</a>><br>
To: "Discussion of biomass pyrolysis and gasification"<br>
<<a href="mailto:gasification@lists.bioenergylists.org">gasification@lists.bioenergylists.org</a>><br>
Subject: Re: [Gasification] raising H2 concentration in<br>
downdraftgasification<br>
Message-ID: <84DD1A65A3DF403A9AB70ECD75760078@usera594fda0bf><br>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";<br>
reply-type=original<br>
<br>
Dear Rex<br>
<br>
In principle, the way to increase the Hydrogen content of "Wood Gas" is to<br>
add external heat to the gasifier inputs, and to reduce the "input heat<br>
loads".<br>
<br>
Actions that accomplish these goals would be :<br>
1: Dry the wood.<br>
2: Preheat the wood.<br>
3: Preheat the air.<br>
4: Add superheated steam to the air<br>
<br>
Best wishes,<br>
<br>
Kevin<br>
<br>
----- Original Message -----<br>
From: "Rex Zietsman" <<a href="mailto:rex@whitfieldfarm.co.za">rex@whitfieldfarm.co.za</a>><br>
To: <<a href="mailto:gasification@lists.bioenergylists.org">gasification@lists.bioenergylists.org</a>><br>
Sent: Friday, December 20, 2013 3:32 AM<br>
Subject: Re: [Gasification] raising H2 concentration in<br>
downdraftgasification<br>
<br>
<br>
> Hi All,<br>
><br>
> The deafening silence on this post is quite interesting. At the very least<br>
> I<br>
> would have thought that someone would have suggested adding steam to the<br>
> reduction zone. What about a charcoal gasifier with steam addition?<br>
><br>
> Any comments on a 1.6MW/2MW thermal gasifier?<br>
><br>
> Kind regards<br>
> Rex<br>
><br>
> -----Original Message-----<br>
> From: Rex Zietsman [mailto:<a href="mailto:rex@whitfieldfarm.co.za">rex@whitfieldfarm.co.za</a>]<br>
> Sent: 16 December 2013 09:57 AM<br>
> Subject: raising H2 concentration in downdraft gasification<br>
><br>
> Hi All,<br>
><br>
> We are looking at a system that will hydrotreat bio oils from pyrolysis,<br>
> catalytic cracking and vegetable oil. For this we need in the region of<br>
> 30kg<br>
> hydrogen/ton oil. At small scale ie 1 ton oil/hour, this works out at, you<br>
> guessed it, 30kg of hydrogen/hour. As this is a small amount in the<br>
> overall<br>
> scheme of things, we are looking at gasifying wood chips and to recover<br>
> the<br>
> hydrogen using pressure swing absorption. What I would like to know is<br>
> whether we can increase the H2 concentration in syngas by tweaking the<br>
> gasifier. Clearly we can look at the water gas shift reaction but, as the<br>
> syngas has to be cooled, washed, pressurised and reheated, it is quite an<br>
> additional investment for the scale we are looking at. If we could simply<br>
> up<br>
> the H2 content, we would go straight from washing to PSA. Residual gas<br>
> would<br>
> be piped to a diesel generator where CO and the like will be combusted<br>
> prior<br>
> to exhaust to atmosphere.<br>
><br>
> For easy mental arithmetic, let us assume a 33% H2 concentration in dry<br>
> syngas. 30kg/hour of H2 is 15kmol/hour or 15/0.33 = 45kmol/hour of syngas.<br>
> A<br>
> kmol of gas has a volume of 22.4 Nm3. So, to get 30kg/hour requires 22.4 x<br>
> 45 = 1000 Nm3 syngas/hour (mental arithmetic here, go with the flow).<br>
> Assuming an 80% PSA recovery this means that we need 1250Nm3/hour of<br>
> syngas.<br>
> Not a bad sized downdraft gasifier! Assuming 6MJ/Nm3, this is around a 2MW<br>
> thermal unit. If we can get the H2 concentration up to say 40%, then the<br>
> syngas requirement would be 37.5kmol/hour or 37.5/45 x 1250 = roughly 80%<br>
> of<br>
> 1250 or roughly 1000 Nm3 syngas/hour. This reduces the size of gasifier to<br>
> 1.6MW thermal and more sensible in size.<br>
><br>
><br>
> ---<br>
> This email is free from viruses and malware because avast! Antivirus<br>
> protection is active.<br>
> <a href="http://www.avast.com" target="_blank">http://www.avast.com</a><br>
><br>
><br>
> _______________________________________________<br>
> Gasification mailing list<br>
><br>
> to Send a Message to the list, use the email address<br>
> <a href="mailto:Gasification@bioenergylists.org">Gasification@bioenergylists.org</a><br>
><br>
> to UNSUBSCRIBE or Change your List Settings use the web page<br>
> <a href="http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org</a><br>
><br>
> for more Gasifiers, News and Information see our web site:<br>
> <a href="http://gasifiers.bioenergylists.org/" target="_blank">http://gasifiers.bioenergylists.org/</a><br>
<br>
<br>
<br>
<br>
------------------------------<br>
<br>
Subject: Digest Footer<br>
<br>
_______________________________________________<br>
Gasification mailing list<br>
<br>
to Send a Message to the list, use the email address<br>
<a href="mailto:Gasification@bioenergylists.org">Gasification@bioenergylists.org</a><br>
<br>
to UNSUBSCRIBE or Change your List Settings use the web page<br>
<a href="http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org</a><br>
<br>
for more Gasifiers, News and Information see our web site:<br>
<a href="http://gasifiers.bioenergylists.org/" target="_blank">http://gasifiers.bioenergylists.org/</a><br>
<br>
<br>
<br>
------------------------------<br>
<br>
End of Gasification Digest, Vol 40, Issue 19<br>
********************************************<br>
</blockquote></div><br></div>