Material Flow Analysis
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Introduction
Material flow analysis (MFA) is a methodology to analyze the flow of "materials" in-and-out of a system.
Built upon the law of conservation of energy, where energy can never be created or destroyed, only transferred, you can use material-balance equations to model complex systems such as the Seed Eco-Home.
See Material flow Analysis on Wikipedia for additional information.
Unanswered Research Questions
- Can the formal concept of "Material flow analysis (MFA)" prove useful in the design of close-looped sustainable systems?
Definitions & Terms [1]
Taken from Chapter 2.1 of Practical handbook of material flow analysis:
- Substance - any (chemical) element or compound composed of uniform units (e.g. Carbon (C), Nitrogen (N), Carbon Dioxide (CO2), and Ammonium (NH3)).
- Good - economic entities of matter with a positive or negative economic value (e.g. wood, drinking water[2], mineral ores, concrete, and automobiles)
- Material - umbrella term for Substance and Good
- Process - transformation, transportation, or storage of Materials.
- Flow and Flux
- Flow - a "mass flow rate." Ratio of mass per time that flows through a conductor (e.g. water pipe). Physical unit examples include kg/sec or t/year.
- Transfer Coefficient
- System and System Boundaries
- Activities
- Anthroposphere and Metabolism
- Material Flow Analysis
- Materials Accounting
Diagrams
Box and Arrow
Using mainly simple boxes and arrows to represent materials flows with a few observed conventions:
- Usually, processes are defined as black boxes
- This means processes within the box are not taken into account
- Only the inputs and the outputs are of interest
- Arrows between boxes are for flows and fluxes of materials
- They have a label describing the material (e.g. "Gasoline")
- Ovals are used for the rates of the flows or fluxes, and the surrounding oval may be omitted due to space constraints.
Taken from section 2.1.4 Process of Practical Handbook of Material Flow Analysis.
Sankey
Sankey diagrams use the width of arrows to denote the rate of the flow or flux of materials in a linked node diagram.