Sciencemadness Discussion Board

Diamonds from CO2

Bedlasky - 31-10-2020 at 13:33

Hi.

I read something about making synthetic diamonds from aeral CO2. Article isn't scientific and there is little info, but I found process which is used for converting CO2 in to carbon.

https://en.wikipedia.org/wiki/Sabatier_reaction

In a nutshell:

1. Electrolysis of water to producing H2 and O2

2. Reduction of CO2 by H2 to CH4

3. Thermal decomposition of CH4 in to elements

This is quite interesting, it is better than mining diamonds from the ground. But I wonder if making diamonds couldn't be simpler. Carbon can be make by carbonization of wood (I know, it is less pure). Which is cheaper than reduction of CO2.

But Sabatier reaction is also interesting in another way. You can make from starting materials (CO2 and H2) several compounds which can be used in organic synthesis, specifically methanol, acetylene and methane.

Ubya - 31-10-2020 at 16:19

using that reaction to make the feed material for a diamond growing process is, unnecessary at the moment.
I think most of the interest for the sabatier reaction is in the production of rocket fuel outside of earth, but it could also be a way to convert CO2 (once scraped from the atmosphere) to methanol and use that as a fuel, so you would have a closed fuel loop. The issue is that big hydrogen plants using electrolysis are still a minority, most of our Hydrogen is made from the steam reforming of methane

itsallgoodjames - 31-10-2020 at 16:58

Not exactly what you're asking, but apparently CO2 thermite may be a viable way to make diamonds from CO2

From canadian patent 2710026:
Quote:

The present invention provides a
method and formulation for the creation of a
dia-mond-carbon bearing material of varying particle
sizes. The material is a detonation by-product of
explosive formulations that employ carbon
diox-ide as the oxidizing agent and a material, such as
powdered magnesium, as the fuel for such
detona-tion.

Seems quite dangerous though

[Edited on 1-11-2020 by itsallgoodjames]

FragranceLover89 - 31-10-2020 at 17:25

There is an somewhat easier source of C. Have you heard of Poly(hydridocarbyne)? It is a polymer that thermally decomposes into diamond. You can make it by electrolysis of chloroform. https://en.wikipedia.org/wiki/Poly(hydridocarbyne). Sorry if this is no help.