**** yeah, start out small with Stretford system or something similar and then 20 years later get something like the Flexorb (sp?) there outside of Evanston. Not to mention the cost of the piping for sour service, then sulfur processing, then acid gas systems, on and on and on. And that is just on the production side, the refining side is just as bad.
The best way to treat H2S in natural gas is with a regenerative amine system ... the direct-conversion procsses don't work worth a ****.
It's more expensive to build a big amine plant initially but in the long run it will save you money because it will just sit there and run as opposed to having to be recharged every month.