Hi all,
We have a hydrogenation fact sheet, though I don't think it focuses as much on the gas delivery: https://ehs.stanford.edu/wp-content/uploads/Hydrogenation-Fact-Sheet.pdf
When writing it, we drew on this excellent paper by Tilak Chandra and Jeffrey Zebrowski, which might have more: https://www.sciencedirect.com/science/article/pii/S187155321500122X
Sincerely,
Jack Reidy (he/him)
Research Safety Specialist, Assistant Chemical Hygiene Officer
Environmental Health & Safety
Stanford University
484 Oak Road, Stanford, CA, 94305
Tel: (650) 497-7614
I acknowledge that the land on which I live and work is the ancestral and unceded land of the Muwekma Ohlone Tribe. As an uninvited guest on these lands, I am a beneficiary of the ongoing displacement of the Ohlone people. I pay my respects to the Native peoples, past and present.
-----Original Message-----
From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU> On Behalf Of davivid
Sent: Friday, July 7, 2023 10:46 AM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Subject: Re: [DCHAS-L] Filling balloons with hydrogen gas
We do hydrogenations and hydrogenolysis in our lab in quantities of up to several moles. The equipment is assembled in a hood. Hydrogen is plumbed into the hood via 1/4" polyethylene tubing cable tied to the drop ceiling from tanks located elsewhere in the lab. The hydrogen regulator is set to deliver the lowest feasible pressure and the outlet valve set to deliver the lowest feasible flow.
The assembled equipment is charged with the reactants and solvents then evacuated using a small diaphragm pump in the hood through a stopcock. A two-way stopcock can be used but a three-way stopcock is preferred as it does not require disconnection of the tubing from the system when switching between evacuation and fill. Hydrogen is then let into the evacuated system via the stopcock and fills the balloon. The hydrogen flow can be shut off at the system using the stopcock. If desired, the evacuation and fill procedure can be repeated multiple times to flush residual air from the system.
We use mylar balloons from the Dollar Store as they are more capacious, stronger, less permeable, and more solvent resistant than rubber balloons. If you go this route you will need to fit the tubing several inches into the mouth of the balloon to reach past the internal valve.
The attached photo shows the method we use to connect the balloons to the system. A gas inlet adapter is fitted with Tygon tubing which then connects to 1/4" polyethylene tubing. The joint between the two types of tubing is secured by two wraps of cable tie and sealed with grease. The tubing extends into the balloon to the point indicated by the arrow. The joint between the balloon and the 1/4" line is sealed with grease and fastened by wrapping several times with the ribbon from the balloon.
Best regards
Dave Lane
Chief Science Officer
Artisyn Laboratories
On 7/6/23 12:27 PM, Laura Cunningham wrote:
> Hi all,
>
> Does anyone have recommendations on how to *safely* fill a balloon with hydrogen? The hydrogen tank in this scenario is in an open lab, and the hydrogen filled balloon is for a hydrogenation reaction. The gas tank is located close enough to a fume hood that piping the hydrogen into the fume hood might be feasible. Wondering what other people’s experiences have been with this.
>
> Thanks,
> Laura
>
> Sent from Proton Mail for iOS
>
> ---
> For more information about the DCHAS-L e-mail list, contact the
> Divisional membership chair at membership**At_Symbol_Here**dchas.org
---
For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org
---
For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org