Typical pollutants from petroleum refineries Which combination best represents the principal air pollutants commonly emitted from petroleum refinery operations?

Introduction / Context:
Refineries process sulfur-containing crude and operate numerous combustion units and process vents. Understanding typical pollutant profiles informs monitoring, permitting, and control technology selection.

Given Data / Assumptions:

• We focus on common, impactful pollutants.
• Emissions arise from heaters, boilers, FCC units, flares, and sour gas handling.

Concept / Approach:
Carbon monoxide (CO) is produced by incomplete combustion. Sulphur dioxide (SO₂) forms when sulfur in fuels or off-gases is oxidized. Hydrogen sulfide (H₂S) occurs in sour refinery streams and may be released if not fully captured/converted (e.g., via amine treating and Claus units). While CO₂ is ubiquitous, it is not typically grouped with “criteria pollutants” in classic MCQs; nitrogen oxide speciation as NO vs NO₂ varies, and SO₃ is a minor fraction compared to SO₂.

Step-by-Step Solution:

Verification / Alternative check:
Emission inventories show significant SO₂ from sulfur-bearing fuels and CO from heaters/flares; H₂S is a key hazard in sour gas systems.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming NO or NO₂ dominate over sulfur species in sour operations; sulfur control is a central refinery environmental challenge.

Final Answer:
CO, SO₂ & H₂S.