Reactions

Letters to the editor

Methane

I read with great interest the C&EN article on methane and climate change (Oct. 25, 2021, page 28). Since methane is generally believed to be a greenhouse gas nearly as important as carbon dioxide despite being less than one two-hundredth as concentrated in the atmosphere (410 ppm for CO₂ versus 1.9 ppm for CH₄), I believe the readers of C&EN would be interested in reading about the chemical origin of that assertion.

Richard Thompson
Baltimore

C-Zero

I read the brief C&EN article written by Michael McCoy about the company C-Zero (Nov. 15/22, 2021, page 34) and followed that up with a look at the company website, which I have to say is singularly lacking in information. A click on the “Technology” link shows the same cartoon reactor shown in the article. It struck me that if you were to replace the methane with pig iron and the carbon with slag, this reactor would look very similar to a Bessemer furnace for the production of steel, although the hydrogen production process is a flow-through process instead of a batch process.

Considering the lack of information about the actual process the company is using to convert methane into hydrogen gas and solid carbon, I would have to say that this article sounds more like an advertisement for the company than the in-depth reporting I expected.

The conversion of methane using a liquid catalyst at high temperature, causing the waste carbon produced to float off the top of the liquid, sounds great. But without at least some evidence that the company has a liquid catalyst that will work at a low enough temperature to make hydrogen for the purpose of burning it for energy—and that will not produce tons of difficult-to-dispose-of waste—this sounds a bit like the proponents of cold fusion.

The absence of any information about the catalytic liquid C-Zero has developed and the operating temperature of the reactor makes it hard to take seriously, but such a process is badly needed as an intermediate step in our efforts to reduce the production of carbon dioxide from burning fossil fuels for energy.

It’s just hard to credit that this particular effort will be part of the mix. I will be looking forward to seeing more information that will establish the credibility of this process.

Ed Birnbaum
Los Alamos, New Mexico