When you shut it down, you shut down combustion, because no exhaust means no intake. And combustion requires air in to exhaust anything. Not magic, ying and yang. In and out. cause and effect.
Regarding the post about wood bio mass and sustainability. I disagree and you sound like some one that has drank to much recent college kool aid. Unfortunately, you have to have been around for more then 25 years to understand a forest ecosystem.
If this is not the case with you, then you are an industry insider and could care less that they are strip mining Maine to send "eco energy" to Mass. The same thing applies to your thinking that applies to MPD's. Cause and effect. Before you go yapping about how sustainable something is, get a historical knowledge about what existed before you did. The Lorax was right. Maine is growing a bumper crop of suckers and red maple, etc. That is the effect of stripping the land to many times.