Assume that coal has a sulfur content of 3% by weight. If all the sulfur is
converted into SO₂ during the combustion process, how much SO₂ is produced per tonne of coal? How much is produced per megajoule of energy produced?

Question

Quizplus · Accepted Answer

The Answer is One tonne of coal would contain (1000 kg)×(0.03) = 30 kg of sulfur. The
molecular mass of

\mathrm { SO } _ { 2 } ext { is } 32 + 2 imes 16 = 64 ext {. The weight percent of } \mathrm { S } ext { in } \mathrm { SO } _ { 2 } ext { is }

( 32 / 64 ) imes 100 = 50 \%

. Thus

1000 \mathrm {~kg}

of coal will yield

60 \mathrm {~kg} \mathrm { SO } _ { 2 }

. Since one tonne of coal yields 31.0 MJ of energy (see Appendix IV) Then

1 \mathrm { MJ }

of energy produced will yield

( 60 \mathrm {~kg} / ext { tonne } ) / ( 31 \mathrm { MJ } / ext { tonne } ) = 1.94 \mathrm {~kg} / \mathrm { MJ }

Assume That Coal Has a Sulfur Content of 3% by Weight