Hacker News new | ask | show | jobs
by state_less 2793 days ago
You could put compressors next to windmills so that on days there is too much wind, you could start up the compressors and make dry ice, liquid nitrogen or some liquid air feed stock.

Cheap energy seems like the key ingredient. The compressor equipment to do the task seems within reach.

One could reverse the process and feed the air (de)compressor gas to make energy on low wind days. I'd be interested to know what the round trip efficiency could be. You could optionally use the compressed products as feed stock in some other industry. Perhaps use blocks of CO2 to make methane or a room temperature liquid gas.
1 comments
gustaf 2793 days ago
Yes, you are correct. Cheap energy is the main input to Direct-Air-Capture. Overflow energy from Solar and Wind is a great source of that.
link
state_less 2792 days ago
Yes, solar seems like it will continue to drop in price and you'd probably want to leverage that savings too.

A mass produced portable compressor unit could also be neat. Something for around the home. A 1kw to 3kw unit could be nice to make dry ice. You practically need to have AC if you want to work in Florida or other tropical climate. There is a big market for AC combined with solar in the U.S. since folks want AC and a good chunk probably also want to use solar. Given that you want cooling at night, a solar powered dry ice maker might be able to compete with solar + battery + AC. The panels can feed directly into the compressor to make the night's dry ice rather than storing the energy in a battery and running the compressor at night.

The bonus is that any efficiency gains in the dry ice maker could be applied to processes further down stream that make methane or heavier hydrocarbons. You get a solar cooling solution and something that could be helpful when bootstrapping synth gas production.

Here are some small high pressure projects / products:

Liquid nitrogen https://makezine.com/2010/06/07/diy-liquid-nitrogen-generato...

Shoebox compressor https://www.shoeboxcompressor.com/

Not sure how you'd separate the CO2 out of the liquid air though.

link