SF Carbon Dioxide Process

Huh. I just had a more or less crazy idea. Could a semipermeable membrane be used to separate carbon dioxide from an atmosphere at a low energy cost? If so it might be possible to build a system using specialized unicellular algae or cyanobacteria that would be more efficient at using sunlight under high CO2 conditions that would be the first step in a really permanent sequestering system.

I could see using something like this in a science fiction story. Perhaps not as the total solution for global warming, but something that people in the future are doing as part of the fight against global warming.