Can I Successfully Freeze Dry Phosphoric Acid-Soaked Carbon at Home?

In summary, the conversation involved a person discussing their process of using Phosphoric acid to activate carbon material. They were limited to a household freezer and a vacuum chamber, and were seeking recommendations on how to achieve their goal. They provided an update on their progress, where they built a small vacuum chamber and were able to successfully turn the material into a powder after four days. They also discussed the purpose of their project, which was to create surface groups and increase porosity in the carbon material.
  • #1
copper-head
31
8
Hello all.
I have carbonaceous material soaking in Phosphoric acid. I'd like to anneal it under an inert environment to activate the carbon. One method used in literature involved freeze drying the mixture and annealing it as is, as opposed to filtering or centrifuging the mixture. However, I am limited to a regular household freezer and a vacuum chamber. Does anyone have recommendations on how to achieve this with specialty tools?
Cheers
 
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  • #2
An update.
I built a small size vacuum chamber and placed the Phosphoric acid soaked material in a petri dish inside the chamber. After pumping the air out, I place the chamber in the freezer. After 24 hours there was build up of sublimated vapor in the chamber, so I pumped that out one more time and replaced the chamber in the freezer.
This is likely to fail. Here my opinion on why drying this into a powder would not work using this method: Freeze drying requires a continuous suction to extract the phosphoric acid vapors out of the chamber. This is would likely not happen using my contraption as my suction is not continuous and hence what I am doing is freezing a substance under vacuum. I'll keep at it for a few more days and update on the progress.
 
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  • #3
What are you actually trying to do ?
 
  • #4
Well, the idea is to dry this carbon which is soaking in Phosphoric acid to obtain carbon-phosphoric acid powder to be later activated at high temperature under inert environment. This creates surface groups on the carbon as well as increases porosity.
 
  • #5
copper-head said:
Well, the idea is to dry this carbon which is soaking in Phosphoric acid to obtain carbon-phosphoric acid powder to be later activated at high temperature under inert environment. This creates surface groups on the carbon as well as increases porosity.
AN Update:
Contrary to my expectations, it worked! the gooey phosphoric acid soaked material turned into powder 4 days later. If anyone is interested in the vacuum chamber schematics, let me know.
 
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Related to Can I Successfully Freeze Dry Phosphoric Acid-Soaked Carbon at Home?

1. What is freeze drying phosphoric acid?

Freeze drying phosphoric acid involves removing water from the acid through sublimation, which is the process of turning a solid directly into a gas without first becoming a liquid. This results in a dry and highly concentrated form of phosphoric acid.

2. Why is freeze drying used for phosphoric acid?

Freeze drying is used for phosphoric acid because it allows for the removal of water without altering the chemical composition of the acid. This results in a more stable and concentrated product that is easier to store and transport.

3. What are the benefits of using freeze drying for phosphoric acid?

The benefits of using freeze drying for phosphoric acid include increased stability, longer shelf life, easier handling and transportation, and a more concentrated product. It also allows for the removal of impurities and water-soluble contaminants.

4. How is freeze drying phosphoric acid performed?

Freeze drying phosphoric acid involves placing the acid solution in a vacuum chamber and lowering the temperature to below freezing. The pressure is then reduced, causing the water to sublimate and leaving behind a dry, powdered form of phosphoric acid.

5. What are the applications of freeze drying phosphoric acid?

Freeze drying phosphoric acid is commonly used in the production of fertilizers, food additives, and industrial chemicals. It is also used in laboratory settings for various experiments and research purposes.

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