[Gasification] Gasification Digest, Vol 6, Issue 17 Where does room moisture go in the winter time?

Wed Dec 13 17:50:44 CST 2006

Dear Ron

"Water vapor is neither created or destroyed." If your dehumidifier could 
not find, it probably escaped elsewhere... do you have an older house? ... a 
fireplace/woodstove? ... an air/air heat exchanger?

These are possible "loss routes" for excess moisture.

Circulating fans do not get rid of moisture... they merely circulate it.

You certainly could dry biomass with an electric heater. You would need 
"make-up air" to displace the moist air generated when moisture came off the 
biomass.

Hope this is helpful.

Best wishes,

Kevin
----- Original Message ----- 
From: "Ron Wagner" <ron.wagner at yahoo.com>
To: <gasification at listserv.repp.org>
Sent: Wednesday, December 13, 2006 7:20 PM
Subject: Re: [Gasification] Gasification Digest, Vol 6,Issue 17 Where does 
room moisture go in the winter time?

>I just dealt with a minor kitchen flood that ended up
> in a corner of the basement. I have also been putting
> humid dryer air into my basement, rather than vent it
> out. I could not collect any water in my dehumidifier!
> Fans quickly dried things out. My house was quickly
> dry. Where does the H20 go?
>
> Could I dry biomass in my electric dryer? The humidity
> dissapears.The heat goes into the house. Maybe I could
> dry it in a burlap bag.
>
> Ron Wagner
> --- gasification-request at listserv.repp.org wrote:
>
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>> Today's Topics:
>>
>>    1. heat required for drying (Toby Seiler)
>>    2. Re: heat required for drying (MMBTUPR at aol.com)
>>    3. Re: heat required for drying
>>       (Rodenhuis, E.J. (Erik Jan, Student TBK))
>>
>>
>>
> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Wed, 13 Dec 2006 05:33:22 -0800 (PST)
>> From: Toby Seiler <seilertechco at yahoo.com>
>> Subject: [Gasification] heat required for drying
>> To: gasification at listserv.repp.org
>> Message-ID:
>> <861580.27485.qm at web38201.mail.mud.yahoo.com>
>> Content-Type: text/plain; charset=iso-8859-1
>>
>> Dear Erik,
>>
>>   I'm probably repeating something that you know.
>> It takes just over 1000 btu to turn one pound of
>> water (liquid) into vapor (after reaching 212f) and
>> in the condensation gives back about 970 btu. Of
>> course one pound of water raised one degree is a
>> btu., but ambient to 212f is relatively small when
>> considering phase change, but not inconsequential.
>> Then come issues like the molecular bound water
>> versus free water, when dealing with woody material.
>>  Generally, I believe drying must target a 10 to 16%
>> moisture content which is about the end of free
>> water and beginning of bound water in wood.
>> Calculating the incoming weight of the water content
>> in the fuel less the outgoing desired will give the
>> weight desired to be removed (as vapor), times the
>> 1000 btu/lb (plus ambient to 212f), gives the energy
>> required to come out of the process, divided by
>> efficiency, for input energy.
>>
>>   One would think that some practical use would
>> exist for the energy given up and not just discharge
>> to the atmosphere as steam.  It takes a lot of
>> energy to dry, but the wise was of the energy from
>> condensation seems prudent.
>>
>>
>>   Regards,  Toby Seiler
>>
>>
>>
>>
>> ---------------------------------
>> Access over 1 million songs - Yahoo! Music
>> Unlimited.
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>> ------------------------------
>>
>> Message: 2
>> Date: Wed, 13 Dec 2006 08:53:40 EST
>> From: MMBTUPR at aol.com
>> Subject: Re: [Gasification] heat required for drying
>> To: seilertechco at yahoo.com,
>> gasification at listserv.repp.org
>> Message-ID: <d2c.1da5f66.32b15fe4 at aol.com>
>> Content-Type: text/plain; charset="US-ASCII"
>>
>>                to   Gasification List      from
>> Lewis L Smith
>>
>> Ref the terms "free" versus "molecular bound" water.
>>
>> I recall from my biomass days that we measured the
>> water content of grasses
>> by heating a sample of the grass until dry in a
>> small oven. This gave us an
>> "oven dry" sample which was then weighed. This
>> weight was subtracted from that of
>> the original material, and the difference was
>> divided by the latter to give
>> an estimate of the percent H20 in the harvested [or
>> sun-dried] grass. Such
>> information was of course essential for making
>> boiler efficiency calculations and
>> for other purposes.
>>
>> I was told by one of the persons performing these
>> tests that the oven only
>> extracted the intercellular water, not the
>> intracellular water, so the dried
>> sample was really only 94% "dry". I eventually came
>> to ignore this distinction in
>> my calculations as everyone else did, and it made no
>> difference of importance
>> for our purposes.
>>
>> Was our intercellular H2O what you call "free"
>> water, and our intracellular
>> what you call "molecular bound" ?
>>
>> Cordially. End of message.
>>
>>
>>
>>
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Wed, 13 Dec 2006 15:54:17 +0100
>> From: "Rodenhuis, E.J. \(Erik Jan, Student TBK\)"
>> <e.j.rodenhuis at student.utwente.nl>
>> Subject: Re: [Gasification] heat required for drying
>> To: <MMBTUPR at aol.com>, <seilertechco at yahoo.com>,
>> <gasification at listserv.repp.org>
>> Message-ID:
>>
>>
> <C655E6719422744297B5910BC105AAD15FBEA1 at EX02.service.utwente.nl>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Lewis, Toby and list,
>>
>> True, but as you say it doesn't make a difference
>> for our purposes. I
>> conducted similar tests on samples, simply dry the
>> samples in an oven at
>> 110 degrees Celsius until they stop losing weight.
>> There is no free
>> water anymore in the cellular space, but there is
>> still bound water in
>> the cell walls.
>> Given the ambient temperature and air humidity we
>> can calculate the EMC
>> (equilibrium moisture content). There is a
>> calculator available at
>> http://www.woodbin.com/ref/wood/emc.htm
>>
>> Toby, thanks. I knew this, when formulating it this
>> way you have the
>> theoretical energy need for drying. As you mention
>> correctly the next
>> step is attributing an efficiency to the drying
>> system used. Same
>> question formulated another way.
>>
>> Erik
>>
>>
>> -----Oorspronkelijk bericht-----
>> Van: gasification-bounces at listserv.repp.org
>> [mailto:gasification-bounces at listserv.repp.org]
>> Namens MMBTUPR at aol.com
>> Verzonden: woensdag 13 december 2006 14:54
>> Aan: seilertechco at yahoo.com;
>> gasification at listserv.repp.org
>> Onderwerp: Re: [Gasification] heat required for
>> drying
>>
>>                to   Gasification List      from
>> Lewis L Smith
>>
>> Ref the terms "free" versus "molecular bound" water.
>>
>> I recall from my biomass days that we measured the
>> water content of
>> grasses
>> by heating a sample of the grass until dry in a
>> small oven. This gave us
>> an
>> "oven dry" sample which was then weighed. This
>> weight was subtracted
>> from that of
>> the original material, and the difference was
>> divided by the latter to
>> give
>> an estimate of the percent H20 in the harvested [or
>> sun-dried] grass.
>> Such
>> information was of course essential for making
>> boiler efficiency
>>
> === message truncated ===
>
>
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