Coals, depending on the grade of coal, will tend to give very high molecular weight PAHs, biomass lower molecular weights, but the analysis for these would not be online and would have to be done by sampling and GC-MS analysis - and you still won't be able to analyse for everything. Its the 3 T's - time, temperature and turbulence, and excess O2 to ensure burnout of the PAHs. Water in the gas is needed to avoid H2 deficiency in the combusted gases, which leads to soot formation.