Question

EGR and lower combustion temperatures contribute to an ____________ in solid soot.

(a) decreases

(b) increases

(c) same

(d) none of the mentioned

I had been asked this question in semester exam.

The doubt is from C.I. Engines in portion Engine Emissions and their Control of IC Engine

Answer 1

The correct answer is:

(b) increases

EGR (Exhaust Gas Recirculation) and lower combustion temperatures contribute to an increase in solid soot (particulate matter) in a CI (Compression Ignition) engine. While EGR reduces NOx by lowering combustion temperatures, this can also lead to incomplete combustion, which increases the production of particulate matter (soot).