Page 235 - Materials Chemistry, Second Edition

11.3 Life cycle economic indicators 233
TABLE 11.3 Other typical indicators for the environmental assessment of industrial systems (Acar and Dincer,
2014; Kaya and Kahraman, 2010; Garcı ´a-Gusano et al., 2016; Aranda Uso ´n et al., 2013).
Indicator Description Method
Energy The ratio of energy output to total energy input η¼(m LHV)/E in
efficiency that can be effectively utilized in the energy where m is the mass flow rate of the investigated
conversion process system, LHV is its lower calorific value, and E in is
the energy input rate of the process
ch
Exergy It is also an efficiency, which is defined as useful ψ ¼(m ex )/Ex in
efficiency output by consumed input, which is a measure where m is the mass flow rate of the investigated
ch
of the thermodynamic perfection of the system system, ex is its chemical exergy, and EX in is the
exergy input of the process
Noise It refers to the environmental impacts regarding The impact of noise on the environmental
sound, which would be harmful to human sustainability depends partly on the decibel level
health of the sound and partly on people’s level of
acceptance
Technical It refers to the state-of-the-art of the adopted It is a subjective indicator, which relies on the
maturity technologies in the system experts’ experience and judgment
Waste It refers to the activities and measures for It includes the waste generation, collection,
management reducing and managing the waste generated by transportation, storage, and disposal, which
the system should be determined by the life cycle inventory
analysis

11.3 Life cycle economic indicators

In the triple-bottom-line-based sustainability assessment, the economic prosperity always
plays a critical role for determining the overall sustainability of the industrial system,
resulting in the development of economic indicators, such as the capital cost, production cost,
operating and maintenance cost, feedstock cost, and replacement cost, etc. However, these
indicators only focus on the costs or economic benefits of a sole stage (especially the
manufacturing stage) of the industrial system, failing to measure the “cradle to grave” cost.
Therefore, some useful economic assessment tools have been developed for evaluating the
economic performance from the life cycle perspective, which can take into account the costs
of designing, developing, running, and disposing of the industrial system.

11.3.1 Introduction of life cycle costing
Life cycle costing (LCC) is a methodology that can measure all costs related to an industrial
system over its entire life cycle, which is preferred to evaluate the system that has a long life-
time and/or high maintenance, use, or disposal costs. Typically, the whole life cost of an in-
dustrial system could embrace the costs regarding purchase, installation, operating and
maintenance, financing, and depreciation. Accordingly, the life cycle costs could be generi-
cally presented as: LCC¼initial capital costs+lifetime operating costs+lifetime maintenance
costs+rehabilitation costs+disposal costs residual value (Li et al., 2017). To some degree,
life cycle costing is similar to environmental-life cycle assessment, where the goal and scope