PTQ Q2 2026 Issue

small steps, if we all take these steps, we can make a significant impact. References 1 Hatcher, N., Weiland, R., Reliable design of sour water strippers, PTQ , Q3 2012, p.83. 2 Le Grange, P., Operational chal - lenges in sour water stripping, PTQ , Q2 2019, p.99. 3 Das, S., Singh, N. K., Configuration study and design of sour water striper units for a refinery revamp, Hydrocarbon Processing, p.89, May 2018.

Overhead from tower

Vent

Signal to product or reux valve

Interface

ILC

Product plus reux

Water

4 Lieberman, N., Sour water strippers: design and operation, PTQ , Q2 2013, p.99. 5 Pilling, M., What steps do we take to keep our sour water stripper at peak performance following a shut- down?, PTQ&A, PTQ , Q1 2021, p.5. 6 Pattreson, W. C., Wells, T. A., Chem. Eng., Sept 28, 1977, p.79. 7 Kister, A. A., Improving Sustainability of Existing Distillation Columns through Exergy Analysis and Revamp Techniques , MS Thesis, Texas A&M University, 2024. 8 Liebert, T., Distillation feed preheat – is it energy efficient?, Hydrocarbon Processing , p.37, October 1993. 9 Hauser, R., Kirkey, R. T., Refinery tests demonstrate fixed valve trays improve performance in sour water stripper, in Distillation 2003: on the Path to High Capacity, Efficient Splits, Topical Conference Proceedings, p.163, AIChE Spring National Meeting, New Orleans, LA, March 31-April 3, 2003. 10 Lenfeld, P., Buttridge I., High costs of quick turnarounds and erro - neous procedures, in Distillation 2013, Kister Distillation Symposium, p.455, AIChE Spring Meeting, San Antonio, April 28-May 2, 2013. 11 Barber, A. D., Wijn, E. F. Foaming in crude distillation units, IChemE Symposium Series , No 56, p.3.1/5, 1979. Henry Z Kister is a Fluor Corp. Senior Fellow and Director of Fractionation Technology. He has more than 35 years of experience in design, trou - bleshooting, revamping, field consulting, control and start-up of frac - tionation processes and equipment. He is the author of four books, the distillation equipment chapter in Perry’s Handbook , and about 150 articles. Kister has taught the IChemE-sponsored ‘Practical Distillation Technology’ course more than 550 times in 27 countries. He obtained his BE and ME degrees from the University of NSW, Australia. He is a Fellow of IChemE and AIChE, Member of the US National Academy of Engineering, and has served on the FRI Technical Advisory and Design Practices Committees for more than 25 years. Norm Lieberman has been a world leader in process troubleshooting, diagnostics, and practical designs for decades. He is the author of 11 textbooks and a large number of articles. Since graduating from Cooper Union in New York in 1964, he was a process design engineer for American Oil Corporation (AMOCO) and later worked directly for the owner of the Good Hope Refinery in Louisiana as a refinery field trouble - shooter. Since then he has been the Principal of Process Improvement Engineering in New Orleans, Louisiana. Lieberman has spent his time since 1984, consulting and instructing Refinery Troubleshooting Seminars, which have been attended by 24,000 engineers, at more than 1,000 seminars and webinars, and providing process designs for crude and vacuum units, delayed cokers, H 2 SO 4 alky units, sour water and amine systems, and many other process units.

Figure 4 Correct configuration of water-removal boot with a flooded condenser

6in above the bottom of the drum (more in case of sludge build-up) to minimise water entry into the reflux line. As always, the devil is in the details. In one refinery’s atmos - pheric crude tower, all these rules were followed, except that there was no standpipe. This led to refluxing water. The water in the 165ºF reflux built up in the tower overhead loop and dissolved chlorides, in turn causing severe corrosion, salting out, and flooding. The carbon footprint of a small, almost costless standpipe was substantial. In Figures 3 and 4, the water-removal boot was inte - gral with the reflux drum, which is the most common boot arrangement. Figure 5 shows an arrangement where the boot was a separate vessel in a reformer debutaniser. The movement of water into the boot and the return of hydrocar- bons displaced by the water back into the drum was through the connecting line. This line was only 1-1.5in in diameter, which became restrictive when the tower operated at high rates. At these high rates, water accumulated in the tower and overhead system, causing off-spec overhead product. What can we do? What can we, as process engineers, do today to lower atmospheric CO₂ concentrations? This article presents only a few examples that demonstrate the many measures within our reach. While our individual initiatives may seem like

Vent gas

Pressure equalising

Condensed debutaniser overhead

Reux drum

Reux and product

1 1/2”

Hydrocarbons

Boot

Water

Figure 5 A water-removal boot separate from the reflux drum

PTQ Q2 2026