Here's a more brief version of Alex's really useful comments, in case anyone wants to reply to the list.
Date: Thu, 30 Jun 2011 11:05:40 -0600 From: [email protected] To: [email protected] Subject: Re: [Digestion] Digestion Digest, Vol 10, Issue 24 Randy Gecko's question was the cost of commercializing the fertilizer. This is more of a concrete number (or series of numbers depending on scale). Value is a much harder calculation, at least for us in Mexico. In some areas, the value of this fertilizer has taken on the value of the tradition chemical fertilizers it is displacing (with a slight discount). In other areas where demand for organics is growing fast, the value is even higher. In areas where the fertilizer has not been proven (or where people evaluate it on pure NPK) the value is lower, or non-existent. Therefore, I think it would be useful to talk about costs of techniques for commercialization, while at the same time talking about the independent process of creating value of the product through outreach, research, and general promotion. Regarding costs and process, we have been filtering the digestate with a simple screen, and then giving it a short residence time in barrels where it tends to stratify. We take the substrate off the top for foliar feeding and adding to irrigation water, and the sludge is applied to the land directly. This has a very small cost of time for each farmer, but as usual, we are dealing with a much smaller scale them most here on this list (read: small farm digesters). This year is very important harvest year for us as we will be reporting the results of a number of test plots that isolated different fertilizer types and techniques, essentially competing head-to-head with common fertilizers in the region. This has been paired with a long-term series of laboratory tests isolating the components of the fertilizer. Our initial results have shown that a single digester will put out very consistent fertilizer quality and type as long as the inputs stay similar (although they absorb a decent amount of variation). However, between digeters in the same region with the same feedstock, there can be a huge amount of variation. This means that our efforts to begin creating a fertilizer market for the digestate require some sort of field testing to qualify it and "certify" it. That may not have to happen very frequently for a single digester, but it should cover nearly all of the digesters for a given program (unless you can show regional similarities we apparently do not have). Proving and demonstrating the value of the fertilizer has been determined by us to be the NUMBER ONE most important aspect for the biogas program (not actually the biogas!), and as mentioned here will be an important factor for pushing AD technology in general. Through the Latin American Biodigester Group we have started a working group whose aim is to conduct unified multi-country research on the quality and use of the "biol" as a fertilizer. I would be very interested in seeing who else from this group may want to contribute or participate in this process. We would ultimately like a field guide for the testing, decision making and use of the biol that can be widely utilized. I look forward to any comments or motivations, or, if anyone has something like that already, please share! Cheers A On Thu, Jun 30, 2011 at 4:58 AM, Christine McKiernan <[email protected]> wrote: Digestate as Fertilizer Per Gordon Gecko's comments (aka Randy Mott) what are the potential values of the separated factions of treated digestate? If this treatment is done on a large scale how are each of the 3 factions removed 'easily'? Just wondering about implementation. Thanks, Christine McKiernan _______________________________________________ Digestion mailing list to Send a Message to the list, use the email address [email protected] 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/
_______________________________________________ Digestion mailing list to Send a Message to the list, use the email address [email protected] 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/
