PE Chemical case studies
PE Chemical · Put your knowledge to work in context.
The PE Chemical exam is one of the Principles and Practice of Engineering (PE) examinations administered by NCEES. It tests for a minimum level of competency in chemical engineering and is designed for engineers who have gained a minimum of four years of post-college work experience in the discipline. The PE Chemical case studies are 5 cases and about 3,937 words.
1Condenser Vacuum Creep on a Light-Ends Column
A vacuum condenser on a light-ends column was designed to condense 25,000 lb/h of overhead vapor (latent heat 150 Btu/lb) at a condensing temperature of 200 °F using 300 gpm of cooling water entering at 85 °F and leaving at 110 °F. The exchanger has 1,500 ft² of surface.
772 words, about 4 min2Raising Reactor Temperature to Chase Conversion
The plant runs a tubular reactor for the liquid-phase consecutive reaction A → B (desired) → C (waste). Both steps are first order.
737 words, about 4 min3Cavitating Charge Pump on a Knockout Drum
A centrifugal pump takes light hydrocarbon (SG 0.62) from a knockout drum at 41 psia and delivers it to a fractionator at 95 °F. The liquid vapor pressure is 38 psia at that temperature.
717 words, about 4 min4Surge Drum Level Loop Amplifying an Upstream Cycle
A feed surge drum (6 ft ID, 8 ft between level taps) receives 90–150 gpm of reactor feed in a roughly 5-minute cycle from an upstream unit. Its outlet goes to a fired heater and then to a reactor; average throughput is 120 gpm.
764 words, about 4 min5Relief Valve Sized for Fire, Not for Cooling-Water Failure
A depropanizer's overhead condenser uses 3,500 gpm of cooling water, and the steam-heated reboiler supplies 40 MMBtu/h. The overhead vapor has a latent heat of about 140 Btu/lb.
947 words, about 5 min