Emissions: 2018 #49

Problem 49. Flare 4.9 MSCF/D sour gas 4% H2S. SO2 emissions TPY? (A) 5.5; (B) 6;(C) 6.5; (D) 7?

Solved using 8 FAC 9 of the 2018 V2 Guidebook. Note emission calculations are rarely found in PE textbooks (they aren't in any of mine). But they are pretty much just dimensional analysis. However, it isn't the thing one can do without knowing the lingo.

Steps:
1. Convert lbs of NG to SCF w/Ideal Gas conversion: 379.3 SCF/lb-mole SO2 Emissions (lb/hr).
2. Flare gas vol.(scf/hr)*(1/379 scf/lb-mole)(64 lb/lb-mole)(%H2S).
3. (4,900 scf/d)(1 d/24 hr)(1/379/scf/lb-mole)(64 lb/lb-mole)(4/100) = 1.38 lb/hr SO2.
4. Emissions (TPY) = (1.38 lb/hr SO2)(8,760 hr/yr)(1 ton/2,000 lb) = 6.04 TPY SO2.

Note the Guidebook walks you through this type of calculation step-by-step so the process is second nature under time pressure.