Plantwide periodical disturbances isolation and elimination in a petrochemical unit

• Autor(a) principal: Farenzena, Marcelo
• Data de Publicação: 2015
• Outros Autores: Kayser, Cristine Alessandra, Trierweiler, Jorge Otávio
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/142315
• topic: Diagnóstico de falhas; Válvulas (Engenharia); Análise espectral; Fault diagnosis; Plant-wide disturbance; Oscillation; Independent Component Analysis

Reducing process variability is crucial to reach a more profitable operating point. Periodical disturbances, however, impose barriers to achieve this goal. Their effect can be strong since one disturbance that appears in a specific loop of a highly coupled plant can be seen in several loops. Thus, isolating their source and diagnosing their cause are essential. In this work, we describe the application of spectral independent component analysis to isolate a periodical disturbance that has a strong impact on the final variability in a polyethylene plant located in Southern Brazil. After the first analysis, the source was detected and the cause identified: valve stiction. To identify the cause (valve, bad tuning, or periodic disturbance), we used the methodology based on higher-order statistics. Once the valve problem had been overcome, the product variance was reduced by 93%.