Process Safety Assessment Considering Multivariate Non-linear Dependence Among Process Variables

• Main Authors: Ghosh, A., Ahmed, S., Khan, F., Rusli, R.
• Format: Article
• Published: Institution of Chemical Engineers 2020
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077430655&doi=10.1016%2fj.psep.2019.12.006&partnerID=40&md5=cee2482fe1be76a644a1297c81db3a96; http://eprints.utp.edu.my/23212/

Nonlinear dependencies among highly correlated variables of a multifaceted process system pose significant challenges for process safety assessment. The copula function is a flexible statistical tool to capture complex dependencies and interactions among process variables in the causation of process faults. An integration of the copula function with the Bayesian network provides a framework to deal with such complex dependence. This study attempts to compare the performance of the copula-based Bayesian network with that of the traditional Bayesian network in predicting failure of a multivariate time dependent process system. Normal and abnormal process data from a small-scale pilot unit were collected to test and verify performances of failure models. Results from analysis of the collected data establish that the performance of copula-based Bayesian network is robust and superior to the performance of traditional Bayesian network. The structural flexibility, consideration of non-linear dependence among variables, uncertainty and stochastic nature of the process model provide the copula-based Bayesian network distinct advantages. This approach can be further tested and implemented as an online process monitoring and risk management tool. © 2019 Institution of Chemical Engineers