Hacker News Reader

Comment by legulere | Hacker News Reader

NH3 and CH4 both get produced with H2. H2 is difficult to transport in a lot of situations, so the idea is to transform it into NH3. For CH4 you need carbon capture which is energy intensive and only makes sense when you need the carbon like in chemical processes.

View on HN

Thank you for your comment. I'm really looking for a more extensive overview, an extensively motivated educated guess.

For example, catching CO2 might be done much more cheaply when burning CH4 at a power station. This might change the equation or not. There also seems to be quite a bit of evolution in reducing the price of carbon capture. [0][1] I seem goals of $30/ton for carbon capture and wonder what factors will change the equation...

[0] https://www.pnnl.gov/news-media/cheaper-carbon-capture-way

[1] https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10....

> For example, catching CO2 might be done much more cheaply when burning CH4 at a power station

There's something quite absurd about catching CO₂ at a power station.

A more sensible source is at cement factories.

I see a certain elegance rather than absurdity in closed cycle green energy storage. Whether H2, NH3, CH4 or something else, chances are that will require high quality CO2 sources. Both CO2 based electric power plants and cement factories look like excellent candidates.

I find the simplicity of compressed CO2 energy storage [0] ten times more elegant, but I'll be happy with any progress towards scalable distributed abundant cheap energy storage.

I guess he is trying to say: use existent gas stations and/or we might be able to capture all the CO2 therein. But I am not gp, obviously.

I just read an estimate that said carbon adds 30% to the cost of producing the hydrogen alone (by electrolysis). If you can use smaller, simpler storage, transport, and consumption structures (for CH4 over H2), that have lower safety demands, then it may be a wash.

And those caverns, pipes and gas turbines are already there. Admittedly they depreciate at 4% - 14%, so not there for all that long in the scheme of things, but they're there now. And the manufacturing and regulatory infrastructures and engineering knowledge are there now too. At global scale.

But NH3 is deadly. Household NH3 is 99% water and then you dilute it 16:1 to use, and still need windows open.

CH4 is environmentally unfriendly, but you don't need nearly as much safety gear to work with it.

The world produces and transports anhydrous ammonia in the millions of tons annually. There is plenty of experience with it. Its hazards are well known and well compensated for.

The world also uses a lot more natural gas and despite uses less precautions.

I work at John Deere, there are a lot of product ideas that never made it to the drawing board because someone came up with an accident scenario involving NH3. The stuff is not to be taken lightly. People who refuse to wear seat belts or motorcycle helmets wear full protective gear when around it.

Reply on news.ycombinator.com