Mixing approach to waste composition and its lower heating value impact on Waste-to-Energy plant

journal article in Scopus

en

Recent research on waste management focuses primarily on the circular economy. This concept leads to increased sustainability by putting emphasis mainly on the reduction of waste production, recycling, and restriction of landfilling. It often already is incorporated in national directives and legislation, while its effective implementation can be aided by mathematical programming. This article focuses on energy recovery from wastes, which is also a crucial part of the circular economy. For optimal operation of the respective Waste-to-Energy plants, it is necessary to take into consideration the varying composition and lower heating value (LHV) of the utilized wastes (or other commodities suitable for energy recovery). Because LHV significantly influences the plant operating mode, waste heterogeneity can result in serious operational problems if bad strategic decisions have been made. The approach discussed herein represents a mixing task which considers the heterogeneity of wastes originating from different sources, the corresponding LHVs, and their impact on final energy recovery. Its implementation includes plant locations and network flows, operating costs (together with the return on investment), waste transport, and corrections of LHVs because all these factors are closely linked to the resulting profits from energy sales. The constraints consist of the necessary balances, such as capacities or heating limits. The developed optimization model is verified using a small waste transport network. Additionally, future research is outlined concerning the extension of the model’s environmental component and the large size of typical, real world optimization tasks of the respective type.

Recent research on waste management focuses primarily on the circular economy. This concept leads to increased sustainability by putting emphasis mainly on the reduction of waste production, recycling, and restriction of landfilling. It often already is incorporated in national directives and legislation, while its effective implementation can be aided by mathematical programming. This article focuses on energy recovery from wastes, which is also a crucial part of the circular economy. For optimal operation of the respective Waste-to-Energy plants, it is necessary to take into consideration the varying composition and lower heating value (LHV) of the utilized wastes (or other commodities suitable for energy recovery). Because LHV significantly influences the plant operating mode, waste heterogeneity can result in serious operational problems if bad strategic decisions have been made. The approach discussed herein represents a mixing task which considers the heterogeneity of wastes originating from different sources, the corresponding LHVs, and their impact on final energy recovery. Its implementation includes plant locations and network flows, operating costs (together with the return on investment), waste transport, and corrections of LHVs because all these factors are closely linked to the resulting profits from energy sales. The constraints consist of the necessary balances, such as capacities or heating limits. The developed optimization model is verified using a small waste transport network. Additionally, future research is outlined concerning the extension of the model’s environmental component and the large size of typical, real world optimization tasks of the respective type.

mixed integer linear programming; waste management; lower heating value

01.08.2020

AIDIC S.r.l.

Milano, Italy

2283-9216

81

1

751–756

6