(53ak) Compressor Fouling Monitoring Methods Identify Fouling Mechanism Changes to Direct Mitigation Performance Improvement

Fouling within the olefins plant cracked gas compressor is a relatively common occurrence. Many gas crackers report some concern with compressor fouling. Significant percentages of liquid and mixed feed crackers also report fouling concerns. In some plants, the fouling occurs to a degree that imposes minimal operational limitations. The primary concern in these plants is an increase in energy consumption, and the fear of limitations if or when something causes the rate of fouling to increase. However, other plants consistently struggle with fouling that limits operational reliability and throughput capacity. A variety of fouling mitigation methods are available: internal coatings, specialty wash-oils and antifoulant additives. In most cases, the fouling is caused by a reactive polymerization mechanism. Quite often, this is a free radical mechanism, but Diels Alder mechanisms also occur. Changes in feedstock and/or changes in cracking severity can change or shift the predominance of the foulant mechanism. As the fouling mechanism changes, the mitigation method effectiveness may also change. In this paper, the fundamental monitoring methods to aid the evaluation of compressor performance and possible changes in fouling mechanism to direct changes in fouling mitigation techniques. Laboratory tests on process stream samples and operational data analysis procedures will be demonstrated. A case history will be presented to demonstrate how this methodology was used to facilitate performance improvement with an additive antifoulant mitigation method.