Pressure drop across Incitec Pivot's ammonia converter baskets significantly increased over a 5-month period in 2006. This pressure drop resulted in a significant loss in ammonia production. In addition, the 35-year-old pressure vessels had developed cracks around the nozzles. Because of these two problems, Incitec Pivot Ltd (IPL) decided to replace the converter baskets, the catalyst and the pressure shells during their 2007 turnaround. After considering the options that were available, IPL decided to replace the old baskets with Casale's new slotted plate design. To maximize production from the new baskets and internals, AmoMax ammonia synthesis catalyst was chosen. This project highlights the need to have plans in place to mitigate any potential risks that could impact plant reliability with some pro-active approaches taken during replacement of the pressure vessels and axial-radial baskets. The paper also describes in detail the systematic root cause analysis of the failure, safety and design reviews of the new baskets, hazop studies, safety measures taken while unloading the old catalyst and dense loading the new catalyst, catalyst reduction, performance tests etc.
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