Loss accounting and estimation of leaks and instrument biases using time-series data

In this work we consider the subject of loss accounting, particularly as it applies to the refining industry. The goal of loss accounting is to evalua te a plant's efficiency through the utilization of all process measurements . Central to this activity is the extraction of emissions information from indirect measurement sources (i.e., process flow and hold up measurements). In this work we present a time-series based approach to the leak estimatio n problem. It is shown that, in a refinery setting, the proposed time-serie s approach can achieve the precision required to meaningfully estimate the low flow rates associated with process emissions. The subject of integratin g the time-series leak estimates with the more traditional direct emission measurements is also discussed.