G'day Again, I thought I should add the last bit of information from A.D. Karve.
Wed Oct 6 The lumps were about 2 to 4 cm across. Yours A.D.Karve All the best, HOOROO Mr. Paul Harris, Room 202 Charles Hawker Building, Faculty of Sciences, The University of Adelaide, Waite Campus, PMB 1, Glen Osmond SA 5064 Ph : +61 8 8303 7880 Fax : +61 8 8303 4386 Roseworthy Campus, Ph : +61 8 8303 7929 mailto:paul.har...@adelaide.edu.au http://www.adelaide.edu.au/directory/paul.harris CRICOS Provider Number 00123M This email message is intended only for the addressee(s) and contains information that may be confidential and/or copyright. If you are not the intended recipient please notify the sender by reply email and immediately delete this email. Use, disclosure or reproduction of this email by anyone other than the intended recipient(s) is strictly prohibited. No representation is made that this email or any attachments are free of viruses. Virus scanning is recommended and is the responsibility of the recipient. -----Original Message----- From: digestion-boun...@lists.bioenergylists.org [mailto:digestion-boun...@lists.bioenergylists.org] On Behalf Of Bill Rucks Sent: Wednesday, 19 October 2011 5:56 AM To: digestion@lists.bioenergylists.org Subject: Re: [Digestion] Digestion Digest, Vol 14, Issue 14 Greetings Could I get the thread relating to Dr Karve biochar and biogas - It seems to bridge between 2 list !! Gasification and Digestion I have looked back through previous issues and vol - but cannot see the original post !! Bill Rucks -----Original Message----- From: digestion-boun...@lists.bioenergylists.org [mailto:digestion-boun...@lists.bioenergylists.org] On Behalf Of digestion-requ...@lists.bioenergylists.org Sent: Wednesday, 19 October 2011 8:00 a.m. To: digestion@lists.bioenergylists.org Subject: Digestion Digest, Vol 14, Issue 14 Send Digestion mailing list submissions to digestion@lists.bioenergylists.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergyli sts.org or, via email, send a message with subject or body 'help' to digestion-requ...@lists.bioenergylists.org You can reach the person managing the list at digestion-ow...@lists.bioenergylists.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Digestion digest..." Today's Topics: 1. Re: [Stoves] Karve connecting Biochar and Biogas (Duncan Martin) ---------------------------------------------------------------------- Message: 1 Date: Tue, 18 Oct 2011 07:04:50 +0100 From: Duncan Martin <duncanjmar...@gmail.com> To: For Discussion of Anaerobic Digestion <digestion@lists.bioenergylists.org> Subject: Re: [Digestion] [Stoves] Karve connecting Biochar and Biogas Message-ID: <cahilkckdfq0xcwq5irlwk4+boygoh3rpwe6dq9-hrzez6bt...@mail.gmail.com> Content-Type: text/plain; charset="windows-1252" Dr Karve's clarification of his original point is helpful - but I think it still leaves some questions. He implies that the stimulatory effect of charcoal is long-term and gradual, so the mechanism isn't likely to be the absorption of a nutrient excess or ant other inhibitors. However, in this context, I'm not convinced by a role as a biomass support: 1. Would the flow velocities in a digester be high enough to strip biomass off such a support medium? If not, it's hard to see a significant role as a source of inoculum. (Bear in mind that anaerobic filters are designed to retain biomass at much higher velocities.) 2. The increased feed rate was 3kg (dry wt) per day, which implies about 30L of food waste per day by volume (neglecting for the moment the free water in which it is suspended). In a 1000L digester, that implies a mean retention time of 33 days. (And a very long retention time of 100 days *before *adding the charcoal.) That implies a large volume of partly-digested solids for colonization by microbial flora. This would provide a major source of inoculum, so it's not obvious that charcoal would add significantly to it. (Yes, native charcoal has a massive surface area per unit weight - but that advantage would disappear if it was covered in biofilm.) 3. In practice, the feedstock would probably be more dilute (depending on the digestion technology in use), so the retention time* would be reduced. However, it seems unlikely that the volumetric throughput would be high enough to negate the above arguments. (*It would be interesting to know what it was...) Yes, Dr Karve's experiment allowed an increased feed rate and, as Crispin says, the higher gas yield is a direct result of the larger volume of "material ingested". However, that doesn't explain *how *the increased feed rate became possible. I would conclude that Dr Karve's observation remains unexplained - we shouldn't jump to conclusions. Duncan Martin PhD Cloughjordan Ireland On 11 October 2011 17:21, Crispin Pemberton-Pigott <crispinpig...@gmail.com>wrote: > Dear Ron?N?All**** > > ** ** > > I think everyone involved in the gas business is clear that the production > increase is the predictable results of a change in fuel (not grasses/dung) > to high starch/sugar feedstocks.**** > > ** ** > > The increase in gas is not apparently the result of the char which is used > more as a culture or host medium to ensure inoculation of the incoming > feedstock. The speed of gas production is the result of the material > ingested.**** > > ** ** > > Dr AD has been in communication with David House (author of the most > important handbook on the subject) and everyone seems agreed on the basics. > The producing increase by this means was demonstrated as long ago as the > 1920?s.**** > > ** ** > > Regards**** > > Crispin**** > > ** ** > > ** ** > > *From:* stoves-boun...@lists.bioenergylists.org [mailto: > stoves-boun...@lists.bioenergylists.org] *On Behalf Of * > rongretlar...@comcast.net > *Sent:* October-05-11 11:05 PM > > *To:* Anand Karve; gasificat...@lists.bioenergylists.org; Discussion of > biomass; biochar; digestion > *Subject:* [Stoves] Karve connecting Biochar and Biogas**** > > ** ** > > AD (cc four lists): > > I have not previously seen the connection between Biochar and Biogas > that you described (below) today on the gasification list. In > particular, you say you "..* filled the digester** > with charcoal, my system accepted three times the normal daily input > and produced three times as much gas.*" > I think what you describe can be a very powerful push for both Biochar and > Biogas. Can you describe what you have learned a little more? > > I know too little of digesters, so this is not clear. I think I know > your kitchen-sized inverted "barrel" gas chamber and think I understand the > last part - of getting three times as much gas in the next 24 hours or less > (and 3X is a huge change!). Does the idea of accepting three times more > mean essentially the same thing? I would think you could "jam" any amount > in; what limits acceptance? > > Do you agree that this is very important new information? Do you agree > this information could help speed up both technologies? I believe there is > wide agreement that Biochar benefits from added biological material (that > would not be long-lived from a sequestration perspective). Is there any > reason to think that the traditional use of digester effluent for ag > improvements will be in any way harmed if it is continued through the > addition of carbon-negative Biochar? Should this not promote sales of your > charcoal-making stoves? > > If I haven't asked quite the right question - please answer the right > one. And congratulations on learning and reporting this. > > Ron > > > > > > The remainder from AD Karve today on the gasification list: > > There are a lot of very simple ideas that need to be tested. I am > currently working on increasing the efficiency of biogas digesters and > feel that it might be possible to reduce the size and the capital > expense of a biogas system. For instance, when I filled the digester > with charcoal, my system accepted three times the normal daily input > and produced three times as much gas. > < snip> > Yours > A.D.Karve > *********************************************** > > _______________________________________________ > Digestion mailing list > > to Send a Message to the list, use the email address > digest...@bioenergylists.org > > to UNSUBSCRIBE or Change your List Settings use the web page > > http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergyli sts.org > > for more information about digestion, see > Beginner's Guide to Biogas > http://www.adelaide.edu.au/biogas/ > and the Biogas Wiki http://biogas.wikispaces.com/ > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.bioenergylists.org/pipermail/digestion_lists.bioenergylists.or g/attachments/20111018/216e60ec/attachment-0001.html> ------------------------------ _______________________________________________ Digestion mailing list to Send a Message to the list, use the email address digest...@bioenergylists.org to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergyli sts.org for more information about digestion, see Beginner's Guide to Biogas http://www.adelaide.edu.au/biogas/ and the Biogas Wiki http://biogas.wikispaces.com/ End of Digestion Digest, Vol 14, Issue 14 ***************************************** _______________________________________________ Digestion mailing list to Send a Message to the list, use the email address digest...@bioenergylists.org to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergyli sts.org for more information about digestion, see Beginner's Guide to Biogas http://www.adelaide.edu.au/biogas/ and the Biogas Wiki http://biogas.wikispaces.com/ _______________________________________________ Digestion mailing list to Send a Message to the list, use the email address digest...@bioenergylists.org to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org for more information about digestion, see Beginner's Guide to Biogas http://www.adelaide.edu.au/biogas/ and the Biogas Wiki http://biogas.wikispaces.com/
