I used to hear people complain about all the “smoke” rising from the stacks at the sawmill I worked at. They never seemed to notice that they didn’t see it during the heat of the summer days.
What they were seeing was steam from water baked out of the sawdust and woodchips we burned to heat the kiln building. It was burned and re-burned to get the most energy available out of the material as possible. It produced very little particulate matter and was filtered before leaving the stacks. What little ash was produced was sold to a company that made concrete.
A lot of the bigger sawmills out west all have cogeneration plants now. It think the one Seneca put in at Eugene, or a few years back was about $7million. At the time there were some type of both state and federal tax incentives.
The only bad story I have ever heard about cogeneration was when either PGE or Enron went out of business they owed a Big Valley lumber in Burney, CA $1 million for electricity they had produced. It put them into chapter 7. They were eventually bought out of receivership by a timber company and are now known as Shasta Green Lumber.
LOL! There were some folks who used to complain about all the “smoke” coming out of a power plant just east of Orlando. Yup. Big freakin’ cooling towers spewing that evil dihydrogen monoxide into the atmosphere. Really looked impressive on the few colder days that would occur occasionally in the winter.