Hey Rex, Please contact Greg Austin ([email protected]), he has a company based in South Africa. I hope he will be of help.
All the best On Sat, Jun 4, 2011 at 2:40 AM, Rex Zietsman <[email protected]>wrote: > David, > > What I have seen down here which sounds and looks attractive is the use of > bladders. Effectively the "inventor" scraped hollows with adjacent walls > and > put in heavy duty bladders that hold about 30m3. He has 11 of them and > empties and fills one a week with chicken litter. As the bladders are > black, > they absorb heat from the sun which helps keep the temperature up. He then > uses two bladders as his gas storage system. By packing rocks onto the > bladder, he can pressurise them to deliver gas using PVC piping to his > generator. His H2S removal system was two 200 litre drums welded together > and filled with machining swarf. Catchpots served both as flash back > arrestors and as condensate drains. Each bag costs about $1500. > > The benefit of this simple system is that it is easily tested at the > one/two > bag size. If successful ie convinces the farmer that it works, it can > easily > be expanded. At the same farm mentioned above, the farmer bought an old > scuba diving tank filling compressor and bought some old gas cylinders. He > then rigged his tractors and truck to take compressed biogas into their air > inlets and save diesel that way. So there are ways of extending the use of > biogas. > > If anyone can add to this type of debate, I believe it would be helpful not > only to me but the list in general. > > Kind regards > Rex > > -----Original Message----- > From: David Fulford [mailto:[email protected]] > Sent: 04 June 2011 10:59 AM > To: Rex Zietsman > Cc: [email protected] > Subject: Re: [Digestion] AD for cow manure > > Hello Rex and listers, > > It depends if you want a set of small cheap systems or a large-scale > sophisticated system. Farms with >500 cows probably need the type of > digester that have been developed by various different German companies. > They are designed to generate power and use hot water from the engine to > keep the temperature in the digester at an optimum value (35 deg.C). They > are designed to be as automated as possible. They use both dung and silage > as the main feedstocks. The only disadvantage is cost. > > In other parts of Africa there are small-scale systems that are much > cheaper, but rely on labour to run them. The majority of these systems use > the dung from just a few cattle to generate cooking fuel for a family. > However, there are much larger systems that can be used to run a generator. > > I do know of installers based in Tanzania and Kenya, capable of making the > larger-scale cheaper units, if you would be interested in this approach. > > Regards, > > David F > > Saturday, June 4, 2011, 7:42:52 AM, you wrote: > > > Hi all, > > > I am going to do something I swore I would never do. Unfortunately, I > > just don't have the time and know that the folks on this list know far > > more than me and can point me in the right direction. > > I live in a rural area where we are subject to occasional power cuts > > (power lines down mostly due to weather) but, more importantly, our > > power bills are rocketing as South Africa races to catch up to the > > rest of the world in terms of cost of power. Historically we had paid > > off coal fired power plants that gave us the lowest cost of power in > > the world. Anyway, now that power costs are rising, own generation is > becoming an economic necessity. > > > In my area we have a large number of dairy farms milking >500 cows. > > These are sizeable operations and the manure they produce is worth > pursuing. > > Typically they all have slurry dams and they spread their manure from > > time to time (much to our temporary dismay while the odour kills us!). > > The question is: what is an economical way of producing gas? Bear in > > mind, efficiency is not an issue in this case. What we are talking > > about is getting gas that can be cleaned up and fed into motors to > > produce power. I am looking at using 3 litre petrol engines that will > > push out about 50kW tops. So, we are not looking for anything fancy. A > > plugflow system would make most sense as they can pump it into the one > > end while the processed material leaves the other. Heating > > suggestions? What about using the engine exhaust to heat water and > > circulate that around the reactor or use it to preheat the incoming > > feed? Here I was simply thinking of a double tank with hot water in the > outer tank... any other suggestions? > > > The other thing these farmers use a lot of is sileage (chopped maize > > that is stored and allowed to ferment). Has anyone had experience > > adding some of this to the AD? > > > Looking forward to hearing from you all! > > Rex > > > > > _______________________________________________ > > 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.bioen > > ergylists.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/ > > > > > -- > Best regards, > David > mailto:[email protected] > ******************************************************************** > Dr David Fulford CEnv MEI, 15, Brandon Ave, Woodley, Reading RG5 4PU > [email protected], Tel: +44(0)118 326 9779 Mob: +44(0)7746 806401 > Kingdom Bioenergy Ltd, www.kingdombio.com, [email protected] > > > > > > > _______________________________________________ > 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/ > > -- Vianney Tumwesige Director - Green Heat (U) Ltd [image: Picture] P.O. Box 10235 Kampala-Uganda 256 (0) 71 237 9889 "The more people are self sufficient in cooking fuel, the more personal and financial freedom they have." - Emma Casson <http://trustvianney.wordpress.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/
