Dear Rex, I would suggest contacting Burdens who is distributing the "Portagester" system in the UK and that could be useful for your intended use and scale.
Their web is www.bioplex.co.uk/*portagester*.shtml<http://www.bioplex.co.uk/portagester.shtml> Best regards, Pablo. 2012/1/9 Alexander Eaton <a...@sistemabiobolsa.com> > I concur on Paul's preference for smaller systems. I have seen a handful > of proposals based on trucking waste from a number of small to medium farms > where they have tried to show energy balance (all the trucks are methane > powered, etc.), but the numbers never add up. Specifically, de-watering > this waste requires relatively well developed systems at each site, and > likely still leaves you with a serious amount of waste water treatment for > each site to achieve healthy discharge levels (in Mexico it is the water, > not the solids that is the treatment challenge). The management system is > also more complex and requires a high level of coordination. The > alternative de-centralized option will likely have similar initial capital > costs, but you can make a better case for farmer investment as they will > reap the benefits. You then have much smaller long-term operating costs, > and all that energy for trucking can go to good use (or maybe still > trucking some effluent fertilizer to local fields). As Paul mentioned, the > option to eventually pipe gas a larger distance for centralized use is an > option that may make sense (but I have not seen it outside of the European > context or large landfill gas context yet). > > Cheers > > A > > > > On Sun, Jan 8, 2012 at 10:51 PM, Paul Harris <paul.har...@adelaide.edu.au > > wrote: > >> G’day Rex,**** >> >> ** ** >> >> Apparently a lot of the biogas comes from the fines/solutes in the liquid >> – I noticed that with piggery effluent the raw effluent was almost >> impermeable to water (it would hold puddles for quite a while) but after >> treatment the solids were pretty free draining (water disappeared in >> minutes).**** >> >> ** ** >> >> I will also raise my usual point in favour of distributed systems – why >> not put smaller (cheaper!) digesters at each farm and if necessary pipe the >> biogas to a central generator (depending on distance)? You will be spending >> a lot of energy on trucking waste in and then you have to truck the >> digestate out from the central facility again. The total capital cost may >> be higher, with more units to maintain, but you can start with one or two >> and spread the finances out a bit as well as helping local employment (I >> guess people will be working on digesters instead of driving trucks!).*** >> * >> >> ** ** >> >> Happy digesting,**** >> >> 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**** >> >> mailto:paul.har...@adelaide.edu.au <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 which may be confidential and/or**** >> >> copyright. If you are not the intended recipient please**** >> >> do not read, save, forward, disclose, or copy the contents**** >> >> of this email. If this email has been sent to you in error,**** >> >> please notify the sender by reply email and delete this **** >> >> email and any copies or links to this email completely and**** >> >> immediately from your system. No representation is made**** >> >> that this email is free of viruses. Virus scanning is **** >> >> recommended and is the responsibility of the recipient.**** >> >> ** ** >> >> *From:* digestion-boun...@lists.bioenergylists.org [mailto: >> digestion-boun...@lists.bioenergylists.org] *On Behalf Of *REX >> *Sent:* Sunday, 8 January 2012 5:26 PM >> *To:* digestion@lists.bioenergylists.org >> *Subject:* [Digestion] 5000 dairy cow AD system**** >> >> ** ** >> >> Hi All,**** >> >> **** >> >> I have been approached to put together a proposal for a centralised AD >> using the manure from 5000 dairy cows. The intention is to pre-concentrate >> the dairy manure slurry and to truck the solids to a central processing >> unit. As silage and grass is extensively used as feed, we would be able to >> co-digest this with the manure to increase the gas output. Furthermore, it >> is intended to use the exhaust gas and the AD liquor to grow macro algae or >> a plant such as hyacinth (an indigenous variety that is not likely to >> become an invader should it get out) which can be shredded and added back >> to digestion. We aim to use the gas for power generation and to use the >> heat to keep the digester(s) warm.**** >> >> **** >> >> Questions:**** >> >> 1. By leaving the water behind, do we lose most/all/some of the FFA? What >> impact would it have on gas production?**** >> >> 2. Can anyone recommend a supplier of technology for this size of plant?* >> *** >> >> 3. 5000 cows is an arbitrary amount at this stage - 10 farms of 500 cows >> each. Is there a better/more economical size?**** >> >> **** >> >> Kind regards**** >> >> Rex Zietsman**** >> >> _______________________________________________ >> 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/ >> >> >> > > > -- > Alexander Eaton > Sistema Biobolsa > IRRI-Mexico > RedBioLAC > > Mex cel: (55) 11522786 > US cel: 970 275 4505 > > a...@irrimexico.org > a...@sistemabiobolsa.com > > sistemabiobolsa.com > www.irrimexico.org > www.redbiolac.org > > > _______________________________________________ > 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/ > > >
_______________________________________________ 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/
