Progressive Reduction of Corrosion Phenomena in a COG Desulfurization Unit

摘要

The environments of chemical plant facilities are complex and multiple corrosion factors are frequently intermingled. When corrosion takes place, these factors interact and may camouflage the underlying causes of the corrosion damage, making it difficult to separate and elucidate them. However, in continuous processing facilities, the time element is a useful additional factor that often can enable different corrosion phenomena to be tracked and their cause(s) identified. In order to take advantage of this situation, real time monitoring techniques are applied to clarify the contributory causes of corrosion attack that is sustained from time to time by the plant during normal operation. In this report of practical on-line monitoring, the use and benefits of the EN instrumentation, in combination with process chemistry analyses, were employed to monitor operating conditions in a full-scale Coke Oven Gas (COG) desulfurization process in which the corrosion rate changed with time.1 The underlying causes of corrosion and the effectiveness of possible countermeasures were evaluated using corrosion simulation software. As a result of progressive improvements, the severe corrosion attack that had been sustained by the facility was reduced to less than 0.05 mm/y after formulation and application of the countermeasures.