Plan to slice New York pizza oven emissions by 75% causes backlash

[ProfessorGAC]

37. Saw The 20 Grand Number Elsewhere

That actually seems a little low to me.
Now, I don't know what the regs are for wood & coal at small scale.
But, if they're anything like large scale regs, just scrubbing the sulfur compounds would not be trivial.
Wood contains lignin which contain natural sulfonates. Coal can be loaded with organic sulfur compounds like mercaptans, disulphides, thioethers, sulfoxides, sulfones, thiophenes, sulfonates, ...
Sulfur compounds burn to for sulfur dioxide. That can be either: scrubbed by caustic water solution in a countercurrent tower to form sodium sulfite, which is then oxidized with peroxide to form harmless sodium sulfate solution, or; catalytically converted to sulfur TRIoxide whichbis then absorbed into water to form sulfuric acid.
These options are expensive or MORE expensive.
And, being small complicates the design, so it's not like a quarter million dollar system becomes $10,000 because it's 1/25th of the size.
If those components of the exhaust are regulated, I honestly don't see how they could do it for $20k, installed.