Crude Column Revamp Using Radial Temperature Profiles
SUMMARY
Designers need to be aware of all the factors influencing packed bed performance such as feed zone mixing problems. Accurate assessment of temperature variations above and below fractionation zones can pinpoint efficiency problems.
TEXT
Tools for troubleshooting distillation columns include sophisticated techniques such as computation fluid dynamics (CFD) and gamma scans, as well as the more fundamental measurements of temperature and pressure. The temperature variation around the circumference of a distillation column is a powerful diagnostic tool, able to infer composition gradient at a given elevation.
Variations in composition and temperature are consequences of problems with internal liquid or vapour stream distribution, poor mixing of external and internal streams at feed locations, or inadequate circulation reflux (pumparound) steam distribution causing uneven cross-sectional area condensation in heat-removal zones. While none of these can be directly measures, they can be inferred from radial temperature measurements at the same elevation in a packed column. This technique was used to facilitate the revamp scope definition of a large atmospheric crude tower at Petrobras refinery...