Hi Rui >Hi, > >I am a gearhead first and foremost. A friend of mine has a VW Jetta diesel >(TDI) and he introduced me to Biodiesel. I do not currently own a diesel >vehicle but I am looking to convert my Toyota LandCruiser to diesel, plus I >want to look at the potential of using a biofuel for heating oil. I found the >idea of using WVO very attractive. >It seems to me from what I am reading (please correct me if I am wrong) that >the key for producing biodiesel is having an effective continuous process >right?
No, not right, as Mark has explained, and as thousands of people all over the place can confirm. >I have looked at all kinds of websites that talk about having developed >some kind of continuous process, but I have not found any real info. Any >suggestions? >The only really interesting info that I found was at >http://www.biodieselgear.com/documentation/ >where there is document (Methanol Super Critical Transesterification Method) >where it is dicussed that under the right circumstances you can produce >biodiesel without acid or base, and in 4 minutes. This type of process seems >to be more inline with the requirements of a continuous process. The drawback >is the required pressure of 35 MPa (~5600 psi) and temperature of 350C. At >first it looked like this was out of reach of a "garage" project, but maybe >with some careful planning... It's been discussed here a few times, it comes up every now and then. Hey, I might as well update the archives again... here you go: >Date: Mon, 4 Nov 2002 01:38:59 +0900 >To: biofuel@yahoogroups.com >From: Keith Addison <[EMAIL PROTECTED]> >Subject: Re: [biofuel] New BioD Method > >Hi Ken > >>Keith writes: >> >> >> >.....Personally (actually not just me, rather wide reservations >> >have been expressed) I'm not very keen on the idea of sodium >> >methoxide at 350 deg C at a pressure of 30 MPa (296.077 atmo- >> >spheres, 2.176 tons/square inch). Not exactly something for >> >the kitchen. >> >>The ONE nice thing about this method is you don't need to use sodium >>methoxide (or any other catalyst). The unusual conditions at >>supercritical state cause the reaction to proceed quickly with just >>alcohol and oil (plus a solvent in some versions). Still need big excess >>of alcohol to drive the equilibrium -- even more than we do because the >>glycerine doesn't drop out. The safety thing is still a concern, certainly >>in ones garage, just because of the high T and P. > >Yes, that is a nice thing, but supercritical methanol is a nightmare. > >A while back I approached a contact for an expert opinion, after >folks started messing with hydraulics gear and saying stuff like >this: > >"I hold no concern for a properly designed reaction vessel under the >needed pressure which on review is around 345 atmospheres / 35MPa / >5080 PSI. at 350 to 400C. Hydraulic excavators, presses and such >machinery often operate at twice these pressures and occasionally >(but not by design) at these temperatures. There is little danger in >this, and no problem obtaining off the shelf pumps etc to achieve >these pressures at any volume." > >The person I asked for an opinion is a Chartered Engineer and a full >Member of the Institution of Electrical Engineers, and a chemist. He >worked for 24 years as a Royal Air Force engineer, including 12 >years spent vetting modifications and designs to aviation equipment. >He was also on five Boards of Enquiry into accidents. This was his >reply: > >>Saka seems to have done some very good, safe industrial research, >>but this is a quest for a "simple, safe, kitchen-sink" method of >>winning the annual Darwin Award. >> >>What they propose, and how they suggest it might be achieved, is >>bordering on fantasy in a home environment. Even a small amount >>exploding would result in horrendous damage, and supercritical >>fluids are notoriously fickle. This is a project that would be >>approached with extreme caution even in an industrial environment. >> >>My personal view is that debating such a process on an amateur >>forum is utterly irresponsible as it glosses over the very real >>dangers involved. Were they to be held accountable for all the >>accidents that would undoubtedly result from keen but ignorant >>amateurs being led to believe that it is a simple matter they can >>try at home, then perhaps we might see a little more caution. >> >>I just wish it were possible to take these people to an ordinance >>factory where controlled explosions are carried out under the >>control of experts so that they could see for themselves just how >>dangerous the whole exercise is. Those that have had no experience >>of explosions just have no notion of how incredibly fickle and >>unpredictable matter is when placed under such duress. Those who >>have had no experience in such matters invariably underestimate the >>protection required, and have no idea of how metals behave when >>subjected to supersonic shock. Instant crystallisation and >>shattering of even ductile metals is not uncommon. >> >>What you have just told me turns my blood cold. As a professional >>engineer I MUST counsel caution. > >Caveat emptor. > >Keith http://archive.nnytech.net/index.php?view=17922&list=BIOFUEL Info-Archive at NNYTech (The list archives is highly recommended, it's a great resource.) To which I might add that as far as I can find out Saka's supercritical method is not in use here in Japan, nor anywhere else that I know of. A project in Kyoto that Saka refers to does produce biodiesel, but not by the supercritical method. >Has anyone looked at the pressures produced by >direct injection fuel pumps? The Dodge/Cummins direct injection pump puts out >24000 psi... Hmmm > >By the way I live in the Boston area and would love to look at how >Biodiesel is >actually produced. Anyone live close by that has a running setup for >processing biodiesel that would be willing to share/show how biodiesel is >actualy produced.. Yes, good... start at the beginning, again as Mark says. Start here: Where do I start? http://journeytoforever.org/biodiesel_make.html#start In fact people often want to find somebody to show them how, but there's no need, it's simple, just do it, you'll be just fine. Best wishes Keith Addison Journey to Forever Handmade Projects Ichijima, Japan http://journeytoforever.org/ >Thanks, >-Rui > >===== >------------------------- >Rui Fernandes >[EMAIL PROTECTED] >Boston - USA >------------------------- Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
