meant NOT at a great amount (as in very small) sorry all. G.
On Sun, Mar 18, 2012 at 2:26 PM, Greg Manning <[email protected]> wrote: > KELBURN, > > THANK YOU ! > > This is the EXACT thing I needed to see.... proves my point, EXACTLY. > > I am now of the firm beleif that we CAN (And DO) water gas shift in > suction type gasifiers, where as, blown (pressureized) gasifiers can > NOT do W/G shift. > > I think the W/G shift is at a great amount, BUT, it sure proves my > caclulations, almost dead on. > > Thank you Thank you Thank you Thank you > > Greg > > > > On Sun, Mar 18, 2012 at 12:14 PM, Kelburn Koontz <[email protected]> wrote: >> Making Ice with Vacuum >> http://www.youtube.com/watch?v=pOYgdQp4euc >> >> Check out the ideal gas law. >> >> Thanks, >> Kel >> >> >> On Sun, 2012-03-18 at 08:10 -0700, Mark Ludlow wrote: >>> “The steam produced in cavitation is like putting water in a bell jar >>> and pulling a vacuum. If there is enough vacuum the water will boil, >>> converting it's temperature into energy for the phase change. >>> Eventually you end up with a chunk of ice in the bell jar.” >>> >>> >>> >>> Not so! Not enough latent heat is lost. Sensible heat must be removed >>> also. In outer space, where there are huge radiative heat losses this >>> applies. If folks could make ice with simple vacuum pumps, who would >>> mess with refrigeration? It takes energy to evaporate water, not just >>> vacuum. >>> >>> >>> >>> Plus, when a gas is adsorbed onto a sieve, energy is released. It >>> takes the same energy (and then some) to regenerate the sieves. No >>> free lunch; no where. >>> >>> >>> >>> >>> >>> From: [email protected] >>> [mailto:[email protected]] On Behalf Of >>> [email protected] >>> Sent: Sunday, March 18, 2012 7:55 AM >>> To: [email protected] >>> Subject: Re: [Gasification] On the subject of H2 and O (was N2 >>> removal) >>> >>> >>> >>> Hi Greg, >>> >>> >>> >>> >>> >>> Sure. Let's to a simple example so my feeble mind can follow it. >>> When I drop cold chips in my gasifier there is some moisture content >>> in the chips...this is liquid water in the wood cells. As the chips >>> burn down into the hearth they get hot and the water changes to steam. >>> This phase change absorbs some amount of energy. Then as the steam >>> goes through the char, some of it does the water gas shift if there is >>> enough heat. This absorbs even more energy. The remaining steam ends >>> up as condensate in the cooler. >>> >>> >>> >>> >>> >>> The steam produced in cavitation is like putting water in a bell jar >>> and pulling a vacuum. If there is enough vacuum the water will boil, >>> converting it's temperature into energy for the phase change. >>> Eventually you end up with a chunk of ice in the bell jar. >>> >>> >>> >>> >>> >>> The water gas shift will not happen in the phase change because there >>> isn't sufficient activation energy availble to make the reaction go. >>> If it did work that way, there would be hydrogen bubbles coming off >>> boat propellers. That would make a COOL rooster tail! >>> >>> >>> >>> >>> >>> Gasifiers do not run a low enough pressure to vaporize the water, like >>> the bell jar. I can get the numbers if you want, but you need to be >>> in -13psi range. That's way more than we pull. >>> >>> >>> >>> >>> >>> Any clearer or still muddy?? >>> >>> >>> >>> >>> >>> Stephen >>> >>> >>> -----Original Message----- >>> From: Greg Manning <[email protected]> >>> To: Discussion of biomass pyrolysis and gasification >>> <[email protected]> >>> Sent: Sun, Mar 18, 2012 10:09 am >>> Subject: Re: [Gasification] On the subject of H2 and O (was N2 >>> removal) >>> >>> Hi Stephen, thanks for the reply. >>> >>> OK, I somewhat understand you, BUT, wouldn't water be doing a phase >>> change in the core of a gasifier as well ? >>> >>> What I was getting at, is if steam is produced in cavitation in cold >>> water, then wouldn't the shift effect also happen within the core >>> during phase transition (from water as a liquid, to water as a vapor, >>> when heated by the core) within the same boundaries of effect as water >>> to steam in the trailing edge of a propeller ? (all of these >>> situations involve lower that normal pressure zones). >>> >>> Aren't contrails produced in water vapor on the wing tips of an >>> airplane because of this same pressure drop phase shift, causing a >>> dew-point change? >>> >>> The core of most gasifiers runs in a dynamic lower than atmospheric >>> pressure ( a very low internal barometric pressure) (suction based >>> units), so the same shifts should apply during phase transition, >>> shouldn't they ? >>> >>> I understand that a pressure fed gasifier would behave differently >>> (and I've personally observed this) than a suction based one, I'm >>> speaking about suction based gasifiers. >>> >>> Somewhat lost, >>> Greg >>> >>> >>> On Sun, Mar 18, 2012 at 8:26 AM, <[email protected]> wrote: >>> > Greg, >>> > >>> > The energy doesn't change. The bond energy in the water is constant >>> > regardless of pressure. >>> > >>> > The cavitation issue is different. It is a phase change phenomenon, not a >>> > chemical change one. >>> > >>> > Stephen >>> > -----Original Message----- >>> > From: Greg Manning <[email protected]> >>> > To: Discussion of biomass pyrolysis and gasification >>> > <[email protected]> >>> > Sent: Sun, Mar 18, 2012 9:02 am >>> > Subject: [Gasification] On the subject of H2 and O (was N2 removal) >>> > >>> > Greetings List. >>> > Since we are speaking input air, I thought I might ask a somewhat >>> > related question. >>> > Water gas shift. I know there are many that have talked about this, >>> > and I understand the basics. >>> > However, here is the question. >>> > At what negative pressure ( negative in/wc) does the shift move down >>> > the temperature scale, to the point of being within the 1000 - 1200 c >>> > area ? >>> > We all know that propeller cavitation produces steam in water that is >>> > 10 c (or there abouts), I have to assume (not being a chemist) that >>> > the same negative pressure effect would also apply to other principals >>> > when dealing with water. >>> > -- >>> > Regards, >>> > Greg Manning, >>> > Brandon, Manitoba, Canada >>> > _______________________________________________ >>> > Gasification 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/gasification_lists.bioenergylists.org >>> > for more Gasifiers, News and Information see our web site: >>> > http://gasifiers.bioenergylists.org/ >>> > >>> > >>> > _______________________________________________ >>> > Gasification 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/gasification_lists.bioenergylists.org >>> > >>> > for more Gasifiers, News and Information see our web site: >>> > http://gasifiers.bioenergylists.org/ >>> > >>> >>> >>> >>> -- >>> Regards, >>> >>> Greg Manning, >>> Brandon, Manitoba, Canada >>> >>> _______________________________________________ >>> Gasification 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/gasification_lists.bioenergylists.org >>> >>> for more Gasifiers, News and Information see our web site: >>> http://gasifiers.bioenergylists.org/ >>> _______________________________________________ >>> Gasification 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/gasification_lists.bioenergylists.org >>> >>> for more Gasifiers, News and Information see our web site: >>> http://gasifiers.bioenergylists.org/ >> >> >> >> _______________________________________________ >> Gasification 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/gasification_lists.bioenergylists.org >> >> for more Gasifiers, News and Information see our web site: >> http://gasifiers.bioenergylists.org/ > > > > -- > Regards, > > Greg Manning, > Brandon, Manitoba, Canada -- Regards, Greg Manning, Brandon, Manitoba, Canada _______________________________________________ Gasification 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/gasification_lists.bioenergylists.org for more Gasifiers, News and Information see our web site: http://gasifiers.bioenergylists.org/
