Thanks Oscar! I really appreciate you catching that. I've revised the post to reflect the more accurate statistics.

With regards to your question, the sources I found seemed to mostly describe adsorption as a relatively simple process -- e.g. Nicomel et. al. specifically highlighted "easy operation and handling" as a major advantage of adsorption (and gave that as a reason for why it has been commonly used in the past).

Hi Jackson! I chose to set this story in an (admittedly very science-fictional) future civilization for a couple of reasons:

1. I was trying to write a story that a random person with no familiarity would find interesting enough to actually read. I think most people would be pretty unlikely to read a story if it were billed as "two people talk about their jobs," and much more likely to read a story about a spaceship pilot.
2. Part of the point of the story is that the analytic frameworks of effective altruism aren't just applicable to our time period, but can (at least in theory) be applied anywhere with the opportunity to do good.