CR4 - The Engineer's Place for News and Discussion ®


Previous in Forum: Ground Source Heat Pump - Calculators and Good Idea (?)   Next in Forum: Water Taste Test Winners
Close
Close
Close
15 comments
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 12221
Good Answers: 143

Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 1:46 PM

Here you go: Wonder what to do next time you are stranded in the Mohave Desert?

Humidity harvester solar powered wonder

I had just been thinking about setting up a green house today that uses solar power for everything, and supplements rain and small well with condensate from air, but I was thinking of using geothermal cold source on air leaving the greenhouse (laden with moisture). The questions is how much more efficient is this new system?

Hey buddy: "What is that in your pocket?"

Buddy: "It is a giant lifesaver".

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru

Join Date: Aug 2007
Location: Earth - I think.
Posts: 2013
Good Answers: 153
#1

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 2:10 PM

"in conditions as low as 20 percent humidity, a level common in arid areas."

Not where I live. Today is cloudy, and they are predicting 10-16%. In the summer, it is usually in the single digits.

__________________
TANSTAAFL (If you don't know what that means, Google it - yourself)
Register to Reply
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 12221
Good Answers: 143
#3
In reply to #1

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 2:26 PM

It is not guaranteed to work where no man should be unless he wants to be polar bear bait, or a toy for an Emperor penguin.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Aug 2007
Location: Earth - I think.
Posts: 2013
Good Answers: 153
#9
In reply to #3

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 5:54 PM

Wrong end of the spectrum - Temperatures are triple digits at that time. I have personally been out working when it was 128F. No polar bears need apply!

__________________
TANSTAAFL (If you don't know what that means, Google it - yourself)
Register to Reply
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 12221
Good Answers: 143
#11
In reply to #9

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/18/2017 8:48 AM

I misinterpreted the single digit part as temperature, sorry. The moisture content of low humidity air at 128 F is actually higher than what you think. Always check the dew point or wet bulb temperature if you want to know the possibility of recovering condensate. That is why the call the heat of Hades a dry heat. The moisture has already been cooked out of all victims.

If deep geothermal cool temperature is (for example) about 55-60 F, and the dew point just happens to be 65-70 F you can see the potential.

In a greenhouse, plants transpire moisture and oxygen is released. The air leaving such enclosed spaces may have pretty high humidity, so it arid zones, it would seem imperative to attempt useful means of condensate recovery and return.

Air conditioning other work areas might be a spin off of this.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 12221
Good Answers: 143
#12
In reply to #9

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/18/2017 9:09 AM

BTW, if it is that hot where you are at, this might be a perfect area to try this new MOF technology as a condensate recovery system, there must be big tonnage of solar energy available there.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Sep 2016
Posts: 673
Good Answers: 8
#2

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 2:26 PM

Oh, this is nice. A life saver indeed.

You should slightly compressed the air stream and cooling it at same time. Use heat pipes and centrifuge, perhaps. A good thesis topic.

Register to Reply Score 2 for Off Topic
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 12221
Good Answers: 143
#4
In reply to #2

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 2:39 PM

Open mouth, insert brain. That doesn't work like that.

Next you should try: disengage mouth, engage brain, research topic, further engage brain, formulate a sentence or two, engage mouth.

Here: look again, and do try to stay on topic this time.

watch this video about MOF's

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Sep 2016
Posts: 673
Good Answers: 8
#5
In reply to #4

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 2:49 PM

These guys has the answers

Register to Reply Score 1 for Off Topic
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 12221
Good Answers: 143
#6
In reply to #5

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 3:00 PM

No magic there, that little guy is just a lizard and live like all other cold-blooded reptiles. Now, that is a really, really cool lizard (at least in the early mornings).

I think I need to search some prior art before I saw anything further about my combined idea.

Basic idea: If one has sufficient energy, then all things are possible. That is why dogs are indispensable in all climates. If one conserves energy, then conservation of other resources is possible. That is all I have to say for right now.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Sep 2016
Posts: 673
Good Answers: 8
#7
In reply to #6

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 3:08 PM

Got it, buddy.

Register to Reply Score 1 for Off Topic
Guru

Join Date: Dec 2016
Posts: 2914
Good Answers: 115
#8

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 4:05 PM

Nifty device!

Register to Reply
Guru

Join Date: Apr 2010
Posts: 5492
Good Answers: 536
#10

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/17/2017 10:10 PM

The question is how much more efficient is this new system?

Here are my thoughts.

I would think it would depend on your definition of efficiency. Do you want to get as much water as possible in a short time, or do you want to get every last bit, however long it takes?

From what I've read, MOFs excel at removing moisture from dry air. I assume it's a two step process where the moisture is absorbed and then driven off by the heat of the sun.

With moist air, maybe the MOF would load up quickly, and then have to be cycled often to remove the moisture. Another process might be quicker at removing the "low hanging fruit".

Since the MOF works best with semi-dry air, if you want to remove every last bit, it would make sense to start with condensation as the first stage followed by MOF to process the air with most of the moisture removed.

Register to Reply
Guru
Engineering Fields - Instrumentation Engineering - EE from the the Wilds of Pa.

Join Date: Feb 2006
Location: middle of nowhere, Pennsylvania
Posts: 2485
Good Answers: 57
#13

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/18/2017 3:39 PM

Geothermal cold source. (???) You mean you will use the coolness of the ground beneath you as a source of cold air? Where you are, unless it is a whole lot different than eastern Texas, the ambient ground temperature at it's lowest is still nearly 70 °F. Is that enough of a difference?

Now up here in the great white north, it is around 40ºF about 300' down in most areas and there is one area where we have a tourist trap that shows them an "Ice Cavern" (a hole down into some rocks with a bit of ice on them - you can't walk into it) as it stays that cool in summer.

__________________
Remember when reading my post: (-1)^½ m (2)^½
Register to Reply
Power-User

Join Date: Mar 2014
Posts: 336
Good Answers: 2
#14

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/20/2017 9:14 AM

To what extent might the various contacted metal ions travel with the water through such a gadget to the final liquid extracted state?

Register to Reply
Guru

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 12221
Good Answers: 143
#15
In reply to #14

Re: Solar Moisture Harvesting Using Metal Organic Framework (MOF)

04/20/2017 10:44 AM

I suspect the MOF is an extremely stable complex, such that as a solid, the quantity of metal ions removed would be <<pg/L. Many of such organic metal complexes that are tailor made, have extremely very low dissociation constants to water.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Register to Reply 15 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Copy to Clipboard

Users who posted comments:

Andrew Westman (1); bullardrr (1); gutmonarch (3); James Stewart (6); Kilowatt0 (2); Phys (1); Rixter (1)

Previous in Forum: Ground Source Heat Pump - Calculators and Good Idea (?)   Next in Forum: Water Taste Test Winners

Advertisement