Malcolm, Sorry for taking so long to get back to you, I missed your post.
I have done some thinking and reading about the CO2 and H2S issues in BioMethane. If the BioMethane is bubbled through lime water, the CO2 will combine with the Calcium in lime water, to make CaCO3 ( calcium carbonate or " chalk " ). This method will also take care of a little of the H2S ( see below ). The H2S is a little trickier, you want to remove the Sulfur, but, leave the Hydrogen, as it would add BTU's to your final product. This can be done a couple of ways depending on what you want as a byproduct. The first way is to bring it in contact with lime/limestone where the Sulfur reacts with the calcium, to form gypsum and the hydrogen goes on it's merry way. The second way, is to bring it into contact with iron filings, and the sulfur reacts with the iron to form iron pyrite ( iron sulfate ). A problem with iron pyrite, is one of disposal. It can be used, in small amounts to neutralize alkaline soils. The iron can also be recharged, by exposing to air, but, that releases the sulfur into the air ( IIRC as sulfur trioxide ), but, with a large amount exposure to the air has to be done slowly or an exothermic reaction occurs ( for the uninformed, this means that it might burst into flame ). I don't have the chemistry know-how to say if you could use the chalk to neutralize the iron sulfate, and what the results might be, but, it might be possible. Perhaps someone else on the list knows. I hope this helps. Greg H. ----- Original Message ----- From: "malcolm maclure" <[EMAIL PROTECTED]> To: <Biofuel@sustainablelists.org> Sent: Thursday, July 21, 2005 15:53 Subject: RE: [Biofuel] Propane - A"Bio" fuel? > Hi Greg, & all > > It's interesting you mention: > > >Bio Methane generally has to be scrubbed of CO2 and H2S, before it is > >useable in any great amount, but, once the H2S and CO2 have been removed, > >Bio Methane can be used just like NG (at lower pressure unless you use a > >compressor to raise the pressure). > > I've started gathering info on Biogas, not for where we are now but for our > planned future move, but I've not seen anything regarding scrubbing the gas. > I had wondered about the need for it. I presume the scrubbing would be done > using absorbent chemicals (trying really hard to remember my inorganic > chemistry but it seems too long ago now!!! Lol) I'd like to know if there > are any innovative solutions to the problem out there. Would water vapour in > the gas cause problems & should it also be removed? Or is all this not > needed when using it as a single domestic supply? > > I'd be interested in any comments. > > Best regards to all > > Malcolm > > > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Greg Harbican > Sent: 21 July 2005 16:15 > To: Biofuel@sustainablelists.org > Subject: Re: [Biofuel] Propane - A"Bio" fuel? > > Not to cause a problem, but, most of the time, the fuel bought at stores is > Propane ( sometimes MAPP gas or even Butane ) not NG. NG requires special > handling procedures and compressors, that are not common except at NG > terminals ( this is part of why NG powered cars are few and far between ). > > I worked security for several years at NG shaving operation, where they > mixed propane with enough air, to bring it down to the same BTU values as > NG, so it could be used in NG appliances. If they didn't do this, the > orifice would have to be changed to one with a smaller opening. If > propane was not mixed with air and the orifice was not one that had a > smaller opening the pilot light in your stove or furnace would be close to 6 > inches long ( instead of half an inch or so ), and you would burn out your > stove. > > Now, if you lower the pressure of the propane going to the appliance, you > can achieve much the same effect. > > The whole idea, is to deliver the same amount of BTU's to the burn area just > outside of the orifice, over the same amount of time. > > BioMethane generally has to be scrubbed of CO2 and H2S, before it is useable > in any great amount, but, once the H2S and CO2 have been removed, BioMethane > can be used just like NG ( at lower pressure unless you use a compressor to > raise the pressure ). > > Greg H. > > > _______________________________________________ > Biofuel mailing list > Biofuel@sustainablelists.org > http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): > http://www.mail-archive.com/biofuel@sustainablelists.org/ > > _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
