>it's not ignition timing (diesel's don't have "ignition"), it's injector >timing, and most diesels are mechanical injection, although I have not >worked on any post 1990 diesels, which may be electronic.
Hi Steve Of course yes - sorry, slip of the, er, mind... It was a post-90 job the guy was talking about. Thanks Keith Addison > >Steve Spence >Subscribe to the Renewable Energy Newsletter: >http://www.webconx.com/subscribe.htm > >Renewable Energy Pages - http://www.webconx.com >Palm Pilot Pages - http://www.webconx.com/palm >X10 Home Automation - http://www.webconx.com/x10 >[EMAIL PROTECTED] >(212) 894-3704 x3154 - voicemail/fax >We do not inherit the earth from our ancestors, >we borrow it from our children. >-- > >----- Original Message ----- >From: "Keith Addison" <[EMAIL PROTECTED]> >To: <biofuels-biz@yahoogroups.com> >Sent: Tuesday, July 10, 2001 1:01 PM >Subject: Re: [biofuels-biz] Additives > > > > Hi Marc, David and all > > > > >100% bio with slightly retarded injection timing will also reduce > > >NOx. The higher cetane value of bio means the combustion chamber > > >pressure rises faster and more reliably so can deal happily with less > > >advance. > > > > Yes - so who needs additives? Though I noticed that NOPEC also uses > > an additive for low-NOx. There are some interesting findings here: > > http://journeytoforever.org/biodiesel_nox.html > > > > Including this one: "I have certified emissions for the urban bus > > retrofit program with EPA (US Environmental Protection Agency) using > > this technology. This package included use of an oxidation catalyst > > to maximize Particulate Matter (PM) reductions (taking advantage of > > the high soluble organic fraction of biodiesel) and a timing change > > to give up some PM reductions while reducing NOx to baseline or even > > past baseline -- the best case was a 28% NOx reduction with a 25% PM > > reduction." > > > > One point though - someone asked how you go about retarding the > > ignition timing on a new-model diesel where everything's computer > > controlled. I don't know from computer controls (25-year-old Land > > Rovers), didn't know how to answer. Any ideas? > > > > >I think a B20 blend gives no more NOx than 100% fossil, is that > > >correct? > > > > I think so. > > > > That's nice information below Marc, thanks. > > > > Best > > > > Keith Addison > > > > >Dave > > > > > >--- In [EMAIL PROTECTED], "F. Marc de Piolenc" <[EMAIL PROTECTED]> wrote: > > > > > > > > Keith Addison wrote: > > > > > > > > > ASomeone's been trying to sell me on an additive > > > > > to reduce NOx. Apparently it does indeed reduce NOx, and > > > > > simultaneously CO, but otoh I think NOx is an overblown problem, > > >I'm > > > > > always a bit suspicious when people chuck the NOx objection at > > > > > biodiesel. Better to debunk the thing rather - "solving" it via an > > > > > additive lends it too much credence: ie, biodiesel ain't no use on > > > > > its own unless you use an additive. > > > > > > > > Correct. NOx is not caused by high combustion temperatures, but by > > > > "crevice combustion" - combustion in tight spaces with a high ratio > > >of > > > > cooled perimeter to volume - which entails rapid quenching and > > > > "freezing" of the back-reaction which otherwise converts NOx back to > > > > free nitrogen and oxygen. Southwest Research Institute proved this > > >at > > > > least twenty years ago, in research sponsored by DoE. I read the > > >report > > > > that long ago, and it could have already been some years old at that > > > > time. > > > > > > > > What this means is that NOx is a combustion chamber and piston > > >design > > > > problem; SRI showed that relatively minor changes in piston crown > > >design > > > > reduced NOx significantly in their test engines. > > > > > > > > Leaving out crevice combustion, diesels should have lower NOx > > >emissions > > > > than spark-ignition engines because their pressure "spike" is not as > > > > pronounced. > > > > > > > > Marc de Piolenc Biofuels at Journey to Forever http://journeytoforever.org/biofuel.html Biofuel at WebConX http://www.webconx.com/2000/biofuel/biofuel.htm To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
