| Material flow cost accounting analyzes input/output relations of material flows in the production process
based on mass balance principles. However, the measured data of a process contains errors representing
a mass imbalance in the system such as that of a wastewater treatment plant. Therefore, measured data
should be verified before establishing mass balance and, subsequently, material flow cost accounting.
Hence, in this work, a novel practical stepwise methodology using data reconciliation technique is
introduced to improve the accuracy and certainty of measurements before material flow cost accounting.
A full-scale petrochemical wastewater treatment plant was selected to establish this methodology. The
presented results of this case study show an error of 3.22% (35244 t/year) between total input and
output streams of wastewater treatment plant demonstrating mass imbalance in the system. However,
the overall mass balance could be closed by simultaneously solving the incidence matrix (system of
balances). The results revealed that by including data reconciliation into material flow cost accounting,
an accurate mass balance can be performed, which is a key element in material flow cost accounting
calculations. The comparison results showed a relatively significant difference between material flow
cost accounting for reconciled and measured data (unreconciled). The developed approach provides a
reliable set of data for implementing material flow cost accounting in the system. Therefore, using this
novel stepwise approach will help decision-makers to enhance both financial and environmental performances more confidently and to define appropriate improvement plans. |