Sciencemadness Discussion Board

Coal tar extract - is it possible in a home lab?

roguerose12 - 15-9-2015 at 22:20

I need to get some fairly pure coal tar and $260 for 100ml is a little steep for me. On top of that there may be a need for more than 100ml of tar (needed quantity TBD) after some experiments have been performed.

I've seen that it can be derived from coal (surprise....) while it is in the process of making coke. IDK how similar it is to wood and pine tar or creosote, but I know if I heat wood in something like a pressure cooker, the tar comes out in the steam or on the sides of the cooking vessel.

If production from start to finish is very difficult and there is a way to refine lower grade tar or any means of making the proce4ss less complicated (read lesss expensive equipment) I would REALLY appreciate any advice on this.

Thank you for taking time ro read this and any suggestions are welcome!

RR

macckone - 16-9-2015 at 09:06

You are going to need a metal apparatus.
You basically put bituminous coal in a can with a takeoff tube.
Heat the can slowly and your product will come off.
First there will be carbon monoxide and hydrogen and some
methane, methanol and carbon dioxide aka water gas.
Next you will get coal gas consisting primarily of methane and hydrogen.
Both coal gas and water gas will contain ammonia which is a major
by product.
At some point you will get an liquids and eventually an oil like substance that
is viscous on cooling. The combination of liquids and oils is coal tar.
If you tube is too long it will clog toward the end of the process.

You will get less than 5% by weight of coal tar from the
coal.

Coal is cheap but this will only leave a crude coal tar.
This will need to be refined and that is a much more complicated
process.

You will divide the coal tar via fractional distillation into
components to refine it. This is done with more controlled heat.
And fractions are recombined to yield the final product.
Someone probably has that procedure in an old book.

unionised - 16-9-2015 at 12:35

Quote: Originally posted by roguerose12  
I need to get some fairly pure coal tar
RR


Why?
It's a horrible mixture of chemicals, many of then toxic and/ or stinky.

Dr.Bob - 17-9-2015 at 06:58

I have to agree that "fairly pure coal tar" is an oxymoron, as it is a complex mixture that depends on the source of type of coal. But if you could get a pile of coal somewhere, and a large paint can or similar metal retort, you could try to make some yourself. Might be able to find an old sample of it on Ebay or some other obscure place.

Just like "pure" gasoline is a crock, as most gasoline contains 100's of components, that vary with source, octane rating, ethanol content, time of year, etc. Equally amusing is that in most states all gasoline comes through the same pipeline, with only a few additives (like ethanol) and detergents added later. So most brands of gasoline in one locality will usually be based on the high or low octane blend from the pipeline, with a minor few differences between each brand, but the gas stations will advertise how much better theirs is, but that is mostly a gimmick as well.

roguerose12 - 17-9-2015 at 16:53

Quote: Originally posted by macckone  
You are going to need a metal apparatus.
You basically put bituminous coal in a can with a takeoff tube.
Heat the can slowly and your product will come off.
First there will be carbon monoxide and hydrogen and some
methane, methanol and carbon dioxide aka water gas.
Next you will get coal gas consisting primarily of methane and hydrogen.
Both coal gas and water gas will contain ammonia which is a major
by product.
At some point you will get an liquids and eventually an oil like substance that
is viscous on cooling. The combination of liquids and oils is coal tar.
If you tube is too long it will clog toward the end of the process.

You will get less than 5% by weight of coal tar from the
coal.

Coal is cheap but this will only leave a crude coal tar.
This will need to be refined and that is a much more complicated
process.

You will divide the coal tar via fractional distillation into
components to refine it. This is done with more controlled heat.
And fractions are recombined to yield the final product.
Someone probably has that procedure in an old book.


Thank you for the explination. It sounds like this might be a by product of syngas or "town gas" (that it was sometimes called).

I found it for sale at some chem supply houses for something like $95 for 100ml and $350 for 500ml

I'm wondering if there is an industry that would produce the "crude" tar which I could later do the fractional distillation.

IDK how difficult this would be, I think it would be a good learning experience for fractional distillation though. I'll see if there are any books or patents on it.

Bert - 17-9-2015 at 23:20

The idea of selling a chemical mixture that is considered hazardous waste, and is a primary soil contaminant at several "super fund sites" for big $'s is highly amusing...

Frack. The stuff is produced by coke making, syn gas production, and just plain BURNING bituminous coal in an unsophisticated aparatus. Ask some Chinese suppliers , you will have it so cheap that the shipping costs will be the majority of your out of pocket expenses, I trow.

macckone - 18-9-2015 at 07:21

This is something that is relatively easily made at home.
Coal is really readily available and there are lots of older books
on the coking process. It is going to cost WAY less than $100
for the apparatus and the coal is readily available in 50 lb bags.
Which will produce about 1kg of coal tar.

http://www.centaurforge.com/Bagged-Smithing-Coal-50lbs-inclu...

In other countries your price of coal may vary but in the US with shipping it is $49.99.

Welding a takeoff pipe on a steel 5 gal pail is not really difficult.
5 gal closed head steel pails are literally available for free if you look.
And they can also be bought but that cost money.

unionised - 18-9-2015 at 09:21

Quote: Originally posted by roguerose12  
Quote: Originally posted by macckone  
You are going to need a metal apparatus.
You basically put bituminous coal in a can with a takeoff tube.
Heat the can slowly and your product will come off.
First there will be carbon monoxide and hydrogen and some
methane, methanol and carbon dioxide aka water gas.
Next you will get coal gas consisting primarily of methane and hydrogen.
Both coal gas and water gas will contain ammonia which is a major
by product.
At some point you will get an liquids and eventually an oil like substance that
is viscous on cooling. The combination of liquids and oils is coal tar.
If you tube is too long it will clog toward the end of the process.

You will get less than 5% by weight of coal tar from the
coal.

Coal is cheap but this will only leave a crude coal tar.
This will need to be refined and that is a much more complicated
process.

You will divide the coal tar via fractional distillation into
components to refine it. This is done with more controlled heat.
And fractions are recombined to yield the final product.
Someone probably has that procedure in an old book.


Thank you for the explination. It sounds like this might be a by product of syngas or "town gas" (that it was sometimes called).

I found it for sale at some chem supply houses for something like $95 for 100ml and $350 for 500ml

I'm wondering if there is an industry that would produce the "crude" tar which I could later do the fractional distillation.

IDK how difficult this would be, I think it would be a good learning experience for fractional distillation though. I'll see if there are any books or patents on it.

A couple of points; it's "Towns gas"- named after Mr Towns.
And it's easy- it used to be a high school experiment- but it's still horrid and stinky.
Why do you want a mixture of toxic carcinogenic goop?
There is probably a better way to get to where you want to be.

ave369 - 18-9-2015 at 14:54

Anyone knows, is there a way to crack coal or peat tar into gasoline-like products?

macckone - 19-9-2015 at 10:37

Quote: Originally posted by ave369  
Anyone knows, is there a way to crack coal or peat tar into gasoline-like products?
short answer is yes. Longer answer, not efficiently or cost effectively. It would be cheaper to use ethanol.