Sciencemadness Discussion Board

Methane synthesis

Jackson - 12-2-2019 at 08:54

I have been wanting to attempt the Miller-Urey experiment for a while now but what I always get hung up on is getting methane for the experiment. I have seen people generate alkenes using the dehydration of alcohols using sulfuric acid, but the smallest alcohol I can find literature for is ethanol. Would it work to generate methane from methanol? I know methane isn't an alkene, but shouldn't the overall process be the same? I know I could get methane from the gas lines, but as I am doing this at home, I don't have a takeoff point, and I don't know if I could get one installed.

Ubya - 12-2-2019 at 09:18

you could decarboxylate sodium acetate with sodium hydroxide, it's one way to produce methane in a lab

XeonTheMGPony - 12-2-2019 at 16:11

or make a 5gallon digester and add an empty tire tube to it as a collection bladder, then simply run through sodium hydroxide to scrub most the un wanted crap out of the gas stream.

FYI I'm envious, I all ways wanted to do this as well.

[Edited on 13-2-2019 by XeonTheMGPony]

Heavy Walter - 13-2-2019 at 05:45

Are you familiar with the Sabatier reaction?
You need to feed hydrogen and carbon dioxide through a nickel catalyst @ 350° C and you get methane.

Jackson - 13-2-2019 at 10:01

Yeah I have looked at it, and it is probably the best because it can give me a constant stream of methane at a pretty reliable rate. The last time I read up about it I could have sworn the catalyst was an expensive platinum group meta type catalyst but if it’s just nickel then I guess it’s something I should probably look more into. Would a metal tube of something like copper be a good reaction tube?

Heavy Walter - 13-2-2019 at 12:21

In the chromatographic world it is employed in "methanizers", used to quantify CO and CO2 with a FID.
Google it.
Beware because the nickel powder is rated as cancerigen. Surely there are alternative catalysts.

Hieron - 22-2-2019 at 08:10

What would be the best alternative catalyst for nickel powder btw?

clearly_not_atara - 22-2-2019 at 15:44

Nickel powder and CO in the same place sounds a bit scary.

I wonder if you could reduce a solution of methyl halide in methanol using aluminum amalgam and get methane. Perhaps even Al/Cu wold work.

Heavy Walter - 27-2-2019 at 04:49

Another option to get methane is the reaction of aluminum carbide with water.

12thealchemist - 27-2-2019 at 07:24

If we're considering all possibilities, one could generate methane via protonation of a methyl Grignard or methyllithium, but this would be a terrible waste of a difficult-to-get reagent