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Comment by sqeaky | Hacker News Reader

A while ago someone posted an article about stacking and freezing farmed biomass. They wanted to sequester CO2 from whatever random stuff that could be farmed cheap and frozen in the winter by hosing it down and running pipes through it then opening or closing the pipes to make it either match the air temp or resist temperature change.

Large swaths of the south simply don't have winter. But how cold does it get and how far from wintery areas is it? Is trucking a bunch of kudzu an option?

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This seems like an absurdly energy-intensive plan because you'd have to spend energy to maintain your mountain-sized pile .. which will heat itself up if it ever reaches warm enough to start decaying.

The most viable farm based approach would be "reverse coal mine": make charcoal from the biomass by reduced-oxygen combustion, then put it all in the big pit you made when you dug up all that coal.

However, there's no economic model for any of this, so carbon capture is never going to go beyond pilot schemes.

Have it grow on wire roap dangling over swamps,withdraw the netting end of season the greenery sinks to the bottom, zero energy effort.

Greenery at the bottom of a swamp would decomposes and emit methane instead of CO2, even worse!

turn the swamp slightly accidic to inhibit life

Wouldn’t the easiest way to be just have goats eat it and then collect and bury the poop?

Maybe, but the goats will turn a lot of the carbon sequestered in the biomass back into CO2. All animals do that to the carbon in the food they eat.

Unless your truck is using a carbon-neutral power source, then no it's not an option. You'll emit more carbon than you sequester.

Trains might be an option, though.

Growing and sequestering enough biomass to slow down climate change means effectively running the fossil fuel industry at the same scale but in reverse. In that spirit, I'll point out that most efficient way of moving carbon-bearing solids per ton-mile is the bulk carrier ships we use for shipping coal.

I suspect some math is in order. A big truck can move a lot of carbon and I suspect there is some range within transport makes sense.

edit - To clarify if a big diesel truck puts X CO2 into the air to move Y tons of CO2 some distance then clearly if X is greater than Y it just doesn't make sense. But, if X is 10% of Y for 200 miles then moving biomass 200 miles might make sense.

Also the transport can be shrunk if the transport is electric. A diesel truck might dump less CO2 into the air than even a coal plant is dumping a ton of CO2 it might be dumping less (or more) per watt which might

Even ignoring that, dry wood is only around 50% carbon. I guess the soil mass is significantly more than that of the atmosphere, but I'd still want to fairly carefully verify we wouldn't be totally screwing something else up by also sequestering the other half of wood. Of course, we'd also have to decide where to place the new wooden mountain range.

What happens in summer?

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