in complete agreement with you on that. Greg
On Sun, Mar 18, 2012 at 9:59 PM, Thomas Reed <[email protected]> wrote: > Greg blown gasifiers typically operate at a few inches of positive pressure > (0.01 ATM) and suction gasifiers at a few inches negative, so both are > essentially at atmospheric pressure unless the pressure is purposely > increased or decreased . > > Tom Reed > > Thomas B Reed > > > On Mar 18, 2012, at 3:26 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 >> >> _______________________________________________ >> 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/
