Importance of Process and Flaring Data and Its Analysis for the Management of Abnormal Situations: An Ethylene Process Case Study

Upset emissions occur during plant startup, shutdown, maintenance, malfunction and flaring incidents. A wide range of these Upsets cannot be managed by the standalone control systems even the advanced ones and need the interfere of plant personnel to correct the causes of this abnormal situation. The technologies needed to help plant personnel to control and prevent abnormal situations are gathered under abnormal situation management. These situations have significant impact on the process industry economy, safety and environment. Moreover, flaring, which is a key but negative method for managing abnormal situations in petrochemical plants, emits huge amounts of greenhouse gases (GHG) and hazardous volatile organic compounds (VOC_s), causing locally transient air pollution and negative community impacts. In addition, flaring is causing huge loss in raw material and energy which could be used to generate more desired products for the industry. Thus, flare minimization during normal and abnormal operational situations has great benefits to environmental, societal, and industrial sustainability. It is not possible to quantify the impacts without understanding the properties and magnitude of these upsets. The analysis of the properties and magnitude of the upset emissions needs extensive amount of historical data. In this paper, an ethylene base case study along with its historical process and flaring incidents data are used to identify underlying causes and indicators that lead to process upsets, i.e. abnormal situations.  The paper will also show potential technique(s) that are recommended to mitigate the incidents and reduce/eliminate its root causes. Moreover, a systematic approach to collect and analyze historical flaring data based on current industrial practices is presented. Finally, the challenges that are faced by environmental agencies in terms of data utilization and documentation are highlighted with some recommended improvements and suggestions.