Question

97. Consider the following: [2011-I]

i) Carbon dioxide

ii) Oxides of nitrogen

iii) Oxides of sulphur

Which of the above is/are the emission/emissions from coal combustion at thermal power plants?

• A. a) i only
• B. b) ii and iii only
• C. c) i and iii only
• D. d) i, ii and iii

Answer 1

The correct option is D d) i, ii and iii

Ans: d

By products of power thermal plant operation need to be considered in both the design and operation.

Waste heat due to the finite efficiency of the power cycle must be released to the atmosphere, using a cooling tower, or river or lake water as a cooling medium. The gas from combustion of the fossil fuels is discharged to the air; this contains carbon dioxide and water vapour, as well as other substances such as nitrogen, nitrogen oxides, sulphur oxides, and (in the case of coal-fired plants) fly ash, mercury and traces of other metals.