Dear Alastair,
What you are saying is true that co-digestion cannot improve the degradation of Lignocellulosic materials, however it has a room of enhancing biogas production through degradation of Fat rich substrates such as Fish waste. Of-course pre-treatment of Lignocellulosic materials is expensive for household or village use in our countries but some how can be minimized by first using Lignocellulosic materials as substrates for mushroom growing and there after use the spent materials after mushroom growing for biogas. I know some people are doing this, though is in lab scale, but data shows some improvement!!!
Thanks for your comments!!
Kassuwi, S.A.A
IDARA YA MOLEKULI BAIOLOJIA NA BAIOTEKNOLOJIA (IMBB)
CHUO KIKUU CHA DAR ES SALAAM
MWALIMU J. K. NYERERE KAMPASI
Box 35179
DAR ES SALAAM,
TANZANIA
From: Alastair James Ward <[email protected]>
To: 'Shaaban Kassuwi' <[email protected]>; "[email protected]" <[email protected]>
Sent: Friday, 16 November 2012, 11:21
Subject: RE: [Digestion] Dung burning vs Anaerobic digestion
Dear Kassuwi,
I usually find cattle manure has a quite acceptable C:N ratio of about 19, but is still useful to co-digest with a high N substrate such as the
fish wastes which are difficult to digest as a mono substrate. I am successfully doing this in partnership with Bioforsk of Norway but there is certainly a risk of inhibition if the mixture is wrong. The addition of fish wastes or similar can drastically increase
the volume of biogas produced, but I do not think it has much effect on the degradation of lignocellulosic materials. This problem is better tackled through pre-treatment processes, of which there are many with varying degrees of effect on different substrates.
The large amount of information regarding pre-treatment of lignocellulosics is mostly because of the interest in second generation bioethanol rather than biogas, but the treatment processes can often be used for either. On the other hand, pre-treatment usually
requires expensive equipment and energy input and so is generally not suitable for the small scale digesters in developing countries which are often discussed on this list.
Med venlig hilsen
|
Alastair James Ward
Post doc. |
Inst. for Ingeniørvidenskab
Aarhus Universitet Blichers Allé 20, Postboks 50 8830 Tjele |
|
Tlf.: 8715 7645
Mobil: 4112 2494 Email: [email protected] |
Tlf.: 8715 6000 Web: www.agrsci.au.dk |
From: Digestion [mailto:[email protected]]
On Behalf Of Shaaban Kassuwi
Sent: 16. november 2012 06:14
To: [email protected]
Subject: Re: [Digestion] Dung burning vs Anaerobic digestion
Sent: 16. november 2012 06:14
To: [email protected]
Subject: Re: [Digestion] Dung burning vs Anaerobic digestion
Dear Members of Digestion group,
The arguments that Cow dung produces low biogas when used in Anaerobic digestion it is the fact which is well known, and the reason has been attributted to high content
of Lignin materials which are difficult to be digested by microbes. However, a number of research has been going on to enhance biogas production from cow dung. One of the technique which seems to be promising is the Co-digestion with another substrate with
for example high Nitrogen contents, as we know Cow dung is rich in Carbon, so when is digested with eg Fish waste which is rich in N in form of Protein could raise the C:N ratio and improve biogas production. To do this one however needs to establish exact
amount of substrate to be co-digested to avoid the problem of Ammonification and Long Chain Fat Acid (LCFA) caused by Protein and Fat Rich substrates. So I would suggest people to start co-digesting and will see improvement to their digestors
Kassuwi
Kassuwi, S.A.A
IDARA YA MOLEKULI BAIOLOJIA NA BAIOTEKNOLOJIA (IMBB)
CHUO KIKUU CHA DAR ES SALAAM
MWALIMU J. K. NYERERE KAMPASI
Box 35179
DAR ES SALAAM,
TANZANIA
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