Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
Author: Subject: Simpler Gregar extractor
12AX7
Post Harlot
*****




Posts: 4798
Registered: 8-3-2005
Location: soldering
Member Is Offline

Mood: informative

[*] posted on 18-9-2005 at 23:27
Simpler Gregar extractor


While staring at something I have warmed on the stove, I thought of the condensation, the distillation, then the extraction.. hmm Gregar extractor? How could you rearrange that thing... aha! Simple enough that surely it's been posted here before, but I'm wondering if it has? There's been enough chat about said extractor that I think I'll post this.

Take a closed jar, or tub, or whatever, with solvent 1 in it. Add heat (warm stove, sun, hotplate..), solvent evaporates and condenses on 2, which has a cooled cone on top (like the "survival still" plan). Condensate drips into container 3 (optionally set on a stand), holding sample to be extracted. As distillate fills 3, it overflows into 1.

I figure this would be a good way to do things if you have a lot of time to wait for something... sit it in the sun and forget about it for a few weeks. It would of course go faster on a hotplate and/or with cooling air or water on the top.

Depending on whether or not your materials are corrosive or require high heat, you could use wood, plastic, metal, glass, whatever you want.

Tim

GregarExtractor.gif - 2kB




Chemistry section: http://webpages.charter.net/dawill/tmoranwms/Chemistry.html

"I could take measurements, but why bother? Science just slows down chemistry!" - Myself
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
Fleaker
International Hazard
*****




Posts: 1100
Registered: 19-6-2005
Member Is Offline

Mood: nucleophilic

[*] posted on 19-9-2005 at 15:31


Hm, I would make part 3 a narrow-mouthed vessel to less evaporation and also immerse that in the substance being evaporated so it does not condense on the bottom of part 3.
View user's profile View All Posts By User
FrankRizzo
Hazard to Others
***




Posts: 200
Registered: 9-2-2004
Member Is Offline


[*] posted on 19-9-2005 at 16:20


That's more soxhlet-based than Gregar (improved soxhlet), but a nice hack if you've got minimal resources and a bunch of time.
View user's profile View All Posts By User
12AX7
Post Harlot
*****




Posts: 4798
Registered: 8-3-2005
Location: soldering
Member Is Offline

Mood: informative

[*] posted on 19-9-2005 at 22:25


Ah, so it is...(I don't know why I haven't looked up Soxhlet until now). They are pretty similar, it just looks like Gregar runs continuously or dripwise rather than toilet-flush-wise ( :P, well it does say siphon on the Soxhlet, so it must have a lot more hysteresis).

Yeah, a narrow mouth would be better, and the whole thing would work much better in a squat container, if you can get one.

Tim




Chemistry section: http://webpages.charter.net/dawill/tmoranwms/Chemistry.html

"I could take measurements, but why bother? Science just slows down chemistry!" - Myself
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
Quince
International Hazard
*****




Posts: 773
Registered: 31-1-2005
Location: Vancouver, BC
Member Is Offline


[*] posted on 24-9-2005 at 17:14


The other difference, besides being continuous, is that the Gregar can be reconfigured to do liquid/liquid extractions as well, with either heavier or lighter solvent.

They show the three configurations here:
http://chemistry.anl.gov/preview/GregarWeb/GE-main.html




\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
View user's profile View All Posts By User

  Go To Top