Which of the following is true about pyrolysis? Choose the correct answer from the options given below.
1.It produces less air pollution than complete incineration.
2.It is carried out in the presence of oxygen.
3.Instead of oxidation, a complex chain of decomposition and other chemical reactions occurs.
4.Pyrolysis often yields useful materials.
5.Pyrolysis is a high-temperature thermal process that is an alternative to incineration.
A1, 2, 3, 4 only
B1, 3, 4, 5 only ✓ Correct
C2, 3, 4, 5 only
D1, 2, 5 only
Correct answer: (B) 1, 3, 4, 5 only
Explanation
Pyrolysis is a high-temperature decomposition of waste carried out without oxygen.
Statement 1 is right as it causes less air pollution than complete incineration.
Statement 3 is right since decomposition reactions replace oxidation.
Statement 4 is right because it often yields useful char, oil and gas.
Statement 5 is right as it is a high-temperature process used in place of incineration, while Statement 2 is wrong because pyrolysis occurs in the absence of oxygen.
Pyrolysis of biomass can produce bio-oil, syngas and biochar.
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