I think the key would be to not use any additional resources to grow, harvest, etc.

This could be done for example by landscaping companies that put their waste through a retort (which could be anything from a stove made of mud bricks, to a mobile trailer that does on-site pyrolysis and use the resulting biochar to fertilize their customer’s plants. Farms could put their waste through it, innoculate the biochar with animal waste, and use it as fertilizer.

I make biochar from my backyard waste in my firepit using a can like this guy.

• https://www.youtube.com/watch?v=9boXHuzMFsA
• https://www.youtube.com/watch?v=ChVxPpnPT-I

Any other method of carbon capture I’ve ever heard about makes no sense. Having hundreds of engineers and workers drive to work for years to engineer and build giant metal and plastic factory/machines with parking lots that require staff that has to drive and park there, etc is nonsense. And even if they work, what would they do with the carbon? Biochar provides a cycle that is accessible to everyone, can be done on-site, uses no fancy technology, nothing is patented, and doesn’t require all this nonsense.