Скачать или смотреть Experimental setup preview of sodium metal production without electrolysis: steps in the description

1. Introduction to the Method:

Objective: The aim is to produce sodium metal without electrolysis and using lower temperatures than the traditional thermochemical dioxane process.

Advantages:

The process avoids high temperatures and flames, making it safe for indoor use.

It offers high yields, typically greater than 90%, compared to only 40% in the thermochemical process.

2. Materials and Setup:

Chemicals Needed:

14 g of magnesium metal (preferably fine powder or turnings)

20 g of sodium hydroxide (available as drain opener)

1-2 g of menthol crystals (used as the catalyst)

125 mL of paraffin oil (mineral oil with no additives)

3 g of sodium metal (optional, as a jump-start material)

Optional Starter Materials:

Alternatively, lithium extracted from a non-rechargeable AA lithium battery can be used as the starter instead of sodium metal.

3. Reaction Process:

Initial Step:

Combine the magnesium, sodium hydroxide, menthol, and paraffin oil in a dry flask.

Starting the Reaction:

The water in the sodium hydroxide must be dealt with first. A small amount of sodium or lithium is recommended to "jump-start" the reaction by consuming the water and preventing it from damaging the flask. The water reacts with the sodium or lithium, generating hydrogen gas.

Without sodium or lithium, this drying step can be skipped.

4. Reaction Setup:

Temperature Control:

Heat the mixture slowly to 120-130°C, allowing moisture to be removed. Afterward, raise the temperature to 200°C for the main sodium-producing reaction.

Gas Monitoring:

A bubbler apparatus is used to monitor gas production (hydrogen) and prevent air from backflowing into the reaction vessel. Paraffin oil is used as the liquid in the bubbler to avoid water, which could cause explosions.

5. Reaction Mechanism:

Main Reaction:

At 200°C, magnesium reacts with sodium hydroxide to produce sodium metal, magnesium oxide, and hydrogen gas. The reaction is indicated by the generation of bubbles.

Role of Catalyst:

Menthol, thel catalyst, allows the reaction to proceed at these relatively low temperatures. Without it, higher temperatures would be required, which could ignite the hydrogen gas.

6. Final Stages:

Completion:

After about 30-40 hours (15 hours with powdered magnesium), the reaction is complete when bubbling ceases. The sodium is then separated from the magnesium oxide by sieving.

7. Purification of Sodium:

First Method (Mechanical Purification):

Melt the sodium and press it together to form a single solid piece, allowing the magnesium impurities to sink to the bottom. The sodium can then be cut or shaved to remove the magnesium.

Second Method (Dioxane Purification):

Use 1,4-dioxane to purify the sodium by boiling it with the sodium. After cooling, the sodium floats on top of the denser dioxane, allowing the separation of magnesium and other impurities. This method provides a cleaner and more efficient separation compared to the mechanical process.

8. Yield and Storage:

Yield:

The method typically provides a 94% yield of sodium compared to the theoretical yield.

Storage:

Sodium should be stored under paraffin oil to prevent oxidation and should be kept in an airtight container.


Acknowledgement: NurdRage