(66c) Best Design and Operational Practices for Charge Gas Compressor Fouling Control and Mitigation

The reliable operation of the charge gas compressor (CGC) is of critical importance for the successful realization of the designed capacities of the steam cracker. Due to the intrinsic characteristics of the steam cracking process, the CGC is susceptible to fouling throughout the course of operations. The buildup of the fouling material over time on the compressor internals (e.g., rotors and casing) and on the interstage coolers leads to a higher pressure drop, increased vibrations, and finally leading to loss of production capacities. Although increasing the compressor operational range can account for some losses in efficiency and head, there is rarely sufficient margin in these machines to accommodate all fouling-related issues. The precise nature of compressor fouling remains poorly understood. However, the fouling mechanism appears to be strongly influenced by temperature, concentrations of foulant precursors and promoters in the cracked gas. It is also important to note that none of the proposed fouling hypotheses can fully explain the observed fouling mechanisms in all instances. Consequently, based on experience, every operating plant must establish its own best practices, tailored to its specific configuration, cracked feedstock, and other factors, for the effective mitigation and control of CGC fouling.