Assumptions:

$-$ Air is composed of $21\%$ O$2$ and $79\%$ N$2$ by volume

$-$ Air is used for combustion

$-$ Complete combustion occurs

$-$ Nitrogen does not undergo a reaction at the combustor.

A $80$ MW thermal power plant burns coal to generate electricity. Assume that $200$ kg$/$h of coal is burned at $15\%$ excess air in this powerplant. Using the below composition for the coal and considering the above assumptions:

$\%$ by weight

Carbon $80$

Hydrogen $3$

Nitrogen $2$

Sulfur $6$

Ash $9$

Determine:

$($a$)$ the volumetric air supply rate in Nm$3/$h

$($b$)$ the resulting $\%$ SO$2$ in the flue gas by volume on dry basis

c$)$ The emission standard for SO$2$ is $2000$ mg$/$Nm$3$ on a dry basis. Is this plant satisfying the emission standard forSO$2?$ Can you give some suggestions if it exceeds the emission standard of SO$2?$