Technical-knowledge-integrated material flow cost accounting model for energy reduction in industrial wastewater treatment

Abstract

A novel simulation model incorporating the concept of material flow cost accounting (MFCA) into a numerical process simulator for wastewater treatment plants (WWTPs) was developed. Cost-related parameters, such as electrical power consumption, were calculated for each unit process by referring to predetermined formulas of design rules and technical knowledge built into the model. These calculated values were then assigned to the outflow stream proportional to the flowrate, allowing each flow stream in the WWTP to be quantified according to the history of assigned costs. This method increased the number of quantity centers in MFCA models regardless of actual data availability, thus contributing complex flow configuration and flexible comparison of improvement approaches related to financial evaluation. Energy cost allocation maps created by this model demonstrated the benefits of anaerobic treatment in the WWTP of a soft-drink factory in Japan. Additionally in this WWTP, the observed values of total power consumption were 40% higher than the simulated values, and improvement approaches, such as instrumental control of aeration, were evaluated for their feasibility and financial impact. These results demonstrated the success of the model in adding and reinforcing analytical and predictive functions in the MFCA survey method.

Keywords

• Material flow cost accounting
• Process simulation model
• Industrial wastewater
• Energy saving
• Food and beverage industry