Abstract
Crude overhead corrosion control is a major mechanical integrity concern within the refinery industry with several reported industry failures. Traditional corrosion monitoring and control revolves around periodic laboratory sampling analysis of the crude overhead sour water to determine the corrosive nature of the process (i.e. pH & Chlorides) and an indication of corrosion rates by the measurement of iron in the sour water.
A Refinery, in the United Kingdom, is a typical refinery processing a wide variety of challenging crudes. As a result, controlling corrosion in their crude overhead system remains one of their biggest challenges. The refinery decided to trial a new automated analyzer for Crude Overhead Systems. The new analyzer is a patented approach, combining equipment and process control, allowing the refinery to continuously measure the boot water pH and automatically adjusting the neutralizer injection to achieve a control range, whilst also measuring chlorides and irons hourly. This system has allowed the refinery to control their neutralizer addition, gaining control of the pH and iron in the overhead system, thus controlling the crude overhead corrosive environment in real time. The instrument has also allowed in-depth understanding of how the process conditions can change (i.e. slate changes) and the effects these changes can have on the overhead corrosion control.