Ok maybe not best. I think you're right about algae doing more scrubbing than our boreal forests.

But I will have to check on the acid thing. As far as I know atmospheric CO2 levels contribute more to ocean acidification.

Well trees do sequester CO2; all be it momentarily until they decompose. But that can be like a couple of hundred years depending on the tree and the environment it grows in.

While burning biomass is at best carbon neutral, shipping it around the world is probably the worst way to do it. The shipping and transportation industry is the largest source of CO2 emissions. Adding to that industry in the name of green energy is misleading at best. Burning locally sourced biomass like some farms do is much better.

Lastly virgin old-growth forests are our best carbon sinks; trees sequestering CO2. Cutting virgin trees to burn as fuel releases previously stored carbon as well as hindering that virgin forest's ability to store carbon.

Any mounted bearing should work.

Here are some links to get you started. https://www.mcmaster.com/products/mounted-bearings https://www.mcmaster.com/products/shaft-collars