Sciencemadness Discussion Board

Fischer-Tropsch process demonstration

plante1999 - 1-12-2012 at 19:18

I developed a small scale demo of the Fisher-Tropsch process for demonstration purpose. This process turn carbon into hydrogen and carbon monoxide by its reaction with water and then react them on an iron catalyst to make liquid fuel such as alkenes and aromatic.

Material:
25 mm by 200 test tube
rubber stopper with one hole for the test tube
L glass tube connected to the stopper
Stand and clamp
9 mm by 70 test tube
a 150 ml beaker

Reagent:
Steel wool
Completely dry carbon small pieces
Copper sulphate or magnesium sulphate
Calcium chloride or salt
Ice and water

First put 7g of copper sulphate or magnesium sulphate in the 25 mm test tube. Add carbon pieces on top of the sulphate salt. Put the steel wool about 5 cm away from the carbon pieces. Then, make an ice-salt bath in the 150ml beaker. Calcium chloride is better, but salt can also be used. Add the 9 mm test tube in the ice and place the L glass tube in the 9 mm test tube. Secure the rubber stopper end of the L tube on the 25 mm test tube.

For the second part strong heating is needed on the iron wool and the carbon. Heat strongly until the sulphate salt is anhydrous. In the 9mm test tube two layer will have formed. Both are clear but the top layer is the desired product. Use a pipette to suck the top layer.

Test the top layer with bromine to prove its content and poor it on a paper piece. Light the liquid to prove its fuel properties.


Explanations:
When heated the sulphate salt dehydrate release water. this water react with the heated carbon to give carbon monoxide and hydrogen. Hydrogen and carbon monoxide will react with the hot iron catalyst to give a variety of more complex carbon compound.


Conclusion:
This short experimentation show how carbon can be turned in liquid fuel in a very low yield. Apparatus requirement are simple and easy to acquire. The product can be refined or fractionally distilled to give a desired product.


This is not an experiment made to be efficient! The process I'm working on for industrial process for chemical synthesis is much more efficient!

12AX7 - 2-12-2012 at 22:11

Neat! Like you say, poor efficiency -- I understand the process normally requires quite high pressures (with relatively low efficiency anyway), so the yield at atmospheric must be tiny. Still, something is more than nothing, which makes it intriguing. I don't think I've heard of hydrous salts used before as a source of steam, good idea.

Tim

blogfast25 - 3-12-2012 at 06:05

Interesting experiment, plante.

Siggebo - 3-12-2012 at 12:10

Very interesting demo!

Poppy - 7-12-2012 at 05:13

I thought the catalyst was actually a fine mixture of iron II, III oxides, not metallic iron. Wouldn't that work too?

plante1999 - 7-12-2012 at 09:20

Actually, there is air in te test tube, and when heated the wool react with it to make a dark gray-red coating. Iron oxide would probably work, but making a good surface area for gas contact would be more difficult.

Manifest - 7-12-2012 at 17:59

Thank you for the share.
I have become interested in this recently and I have been wondering if such an experiment could be done.

Manifest - 3-1-2013 at 16:36

I don't get it, what's going on here during this and why is copper sulfate needed?

Vargouille - 4-1-2013 at 04:42

Copper sulfate is used as a source of water. As it is heated, it releases water. The water passes through the carbon, producing hydrogen and carbon monoxide, which, upon contact with the steel wool, forms the desired product mixture.

Manifest - 4-1-2013 at 05:57

Quote: Originally posted by Vargouille  
Copper sulfate is used as a source of water. As it is heated, it releases water. The water passes through the carbon, producing hydrogen and carbon monoxide, which, upon contact with the steel wool, forms the desired product mixture.


Thanks, but couldn't you just use actual water instead? Or something else that produces water.

I don't have an abundant supply of Copper Sulfate.

Edit: I suppose it wouldn't be used up anyway you could just hydrate it again. But couldn't you just add water? I don't see why not

[Edited on 4-1-2013 by Manifest]

Vargouille - 4-1-2013 at 06:19

You could use magnesium sulfate as well. I believe the reason is to produce a higher temperature steam, which would react more readily with the carbon. With water, the steam will come off at little higher than 100C, but with hydrated salts, the last few moieties of water come off above 100C.

Manifest - 4-1-2013 at 14:03

Quote: Originally posted by Vargouille  
You could use magnesium sulfate as well. I believe the reason is to produce a higher temperature steam, which would react more readily with the carbon. With water, the steam will come off at little higher than 100C, but with hydrated salts, the last few moieties of water come off above 100C.

Does this make Methanol and how efficient is this?
How much would this make if I scaled it up

plante1999 - 4-1-2013 at 16:27

Quote: Originally posted by Manifest  

Does this make Methanol and how efficient is this?
How much would this make if I scaled it up


I do not think it make methanol, and like I said in the first post it is not efficient. You will have hard time to make a liter of it without automated setup, and somewhat large scale.