Upset
emissions occur during plant startup, shutdown, maintenance,
malfunction, and flaring incidents. A wide range of these upsets cannot
be managed by standalone control systems; plant personnel intervention
is necessary sometimes. The methods needed to assist plant personnel
to control and prevent abnormal process operations are gathered under
abnormal situation management. Abnormal operations that lead to flare
have significant economic, environmental, and safety impacts. Flaring
is necessary for managing process upsets, however, it leads to the
emission of greenhouse gases (GHG) and volatile organic compounds
(VOCs), causing negative social impacts and local transient
air pollution. In addition, excessive flaring results in energy and
raw material losses. These are valuable commodities that must be sustained.
Therefore, flare minimization during normal and abnormal operational
situations has great environmental, industrial, and societal benefits.
It is not possible to quantify the impacts without understanding the
properties and magnitude of these upsets. Such analysis requires extensive
amount of historical data. There are large sets of design, operational,
and flaring data readily available; however, the challenge when it
comes to flare mitigation is in using them effectively and in a timely
manner. In this Article, a systematic approach to collect, analyze
and utilize historical flaring data based on current industrial practices
is presented. An ethylene base case study along with its historical
process and flaring incidents data is used to demonstrate the significance
of using and integrating data within developed flare management strategies.
In the presented case, design and historical process data are used
to assess the environmental impacts of abnormal incidents and to identify
underlying causes and indicators that lead to process upset, that
is, abnormal situations. The data sets are utilized within an optimization
algorithm to identify design alternatives to mitigate process incidents
and reduce its root causes. The paper highlights the challenges that
are faced by environmental agencies in terms of data utilization and
documentation.