Comment by cjbenedikt
2 months ago
It is actually amazingly energy efficient as the electrolysis produces H2 at one electrode and consumes it at the other. Hence, very little additional energy is needed. As offshore wind produces a lot of surplus energy at night - this could be used. So far it was possible to capture approx. 92% of the CO2 in the amount of seawater handled. Could likely be increased to 94% - 96%.
You're still ignoring the fact that there is an absolutely unfathomably insane amount of water on the planet.
The world's largest pump (according to a quick search) can pump 60,000 liters per second. The oceans contain over 1.3 billion cubic kilometers of water. One cubic kilometer is a trillion liters. It would take this pump - the largest pump in the world - 192 days to move one cubic kilometer of water.
Let's be charitable and say we can make a noticeable dent in ocean CO2 if we could only process 1% of the ocean's water per year. That's about 13 million cubic kilometers. Let's be generous and say one of these pumps can do 2 cubic kilometers a year even though it's a bit less. So we'd need 7.5 million of these pumps - and of course we'd also need each of them to be connected to a facility that's capable of processing all the water as quickly as the pump can supply it.
This is the problem with carbon capture. We can't build many/large enough capture facilities to make a difference.