MFA Flashcards
Describe the four main steps in the procedure of MFA (that is, the type of MFA that is included in the course and in the literature by Brunner). You should show that you understand what is performed in each step.
- Problem definition
o Define problem and adequate goals, ev substance
o Consider existing standards and legislations - System definition
o Selection of substances, system boundaries, goods (products containing material) and processes (process boxes)
o Determine relevant goods containing the substance, and a rule to calculate the substance – grade
o System definition – space and time
Region, company facility, household
Time has to be long enough to outweigh momentary unsteadiness of the system – often 1 year - Determinations of flows and stocks
o Mass flow of goods and substance concentration in these flows are assessed
Data gathering,
Assumptions – approximations or cross comparisons between similar systems
Can also be measured depending on resources available for the MFA
o Substance flows (inflow and outflow) and stock are calculated
Waste flows, emissions of pollutants and substance concentration in air, water, and soil
Substance flow = mass flow of goods * substance concentration in the good
o Mass balance
Sum massflow input = sum massflow output + mass storage
o Consider uncertainties - Illustration and interpretation
o Results presented in an appropriate way to visualize the conclusions and to facilitate implementation of goal-oriented decisions.
o Present relevant results in a clear and trustworthy way.
o To maximize impact of the MFA findings, visualization and conclusion are of fundamental importance
These procedures do not have to be executed in a strictly consecutive order, but rather be optimized. Can make assumptions and estimations in the beginning and then refine and improve the system throughout the study.
Explain
i) how an accumulated stock of a material in society (i.e. the total stock and not the annual change), and
ii) emissions of a material from the use phase,
can be calculated in a situation when data cannot be found in the literature or in the statistics.
i) Accumulated stock in society (total stock) can be assessed two ways. 1. By assessing the volume and density of the stock, often used when the stocks do not change significantly for long periods of time. 2. Fast changing stocks are calculated by taking the difference between input and output over an appropriate timespan
ii) Emissions of a material from the use phase can be calculated by emissions of pollutants and substance concentration in air, water, and soil
Draw a typical flow chart for an MFA for a material in a country that includes a relevant set of processes, flows, and stocks. There should be names on processes and flows so that it is possible to understand the flow chart
Lithosphere - [Extraction] - (material) - [Production] - (refined raw material) - [manufacturing] - (products) - [Use (stock)] - (waste) - [waste management] - [Landfill and recycling]
waste from production and manufacturing
Ev import and export connected to production and manufacturing
For who can the results of an MFA be useful and why?
Attractive as a decision-supporting – municipalities, policy makers,
companies tool in resource management
Waste management and env management – researchers with specialties in env.
For:
- early recognition of potentially harmful or beneficial accumulations or depletions of stocks, as well as for timely prediction of future env. loads
- setting of priorities regarding measures of env. protection, resource conservations and WM
- the design of goods, processes and systems that support env. protection, resource conservations and WM
Describe how one could calculate these figures, when one cannot find them in the literature:
- the flow of a material in imports of products
Substance flow = mass flow of goods * substance concentration in the good
All imports of the relevant goods in a study over a decided period of time
Describe some different ways in which data can be found, e.g. different types of data sources, and how cross checking and uncertainties can be handled.
- Data taken from databases – regional, national and international bodies such as bureaus of statistics, industrial associations, professional societies and consumer organizations can be good sources of specific data, or environmental agencies for waste and pollutants, articles
- Measured directly on site
- Interviews
- Cross-comparison –cross-checking between similar systems
- Proxies - figures that help approximating or estimating the data of interes
- Need to check that they are eligible to take ex zink flow from Sweden applying it to USA
Definition of MFA
- MFA is a systematic assessment of the flows and stocks of materials within a system defined in space and time. It connects the sources, the pathways, and the intermediate and final sinks of a material.
- Control the MFA by a mass balance, comparing inputs, stocks, and outputs (waste) of a process
- Attractive as a decision-supporting tool in resource management, waste management and env management.
- MFA is performed without considering other anthropogenic factors, like energy, space, information, and socioeconomic issues. These issues must be included to manage the anthroposphere responsibly, and to take into consideration when interpreting the MFA results
- MFA alone is not sufficient too to assess or support engineering or management measures, but is an important first step and necessary base for such tasks
Define the anthroposphere
The human sphere of life o Agriculture o Industry, trade, commerce o Private households o Waste management
Design principles in industrial ecology that suggest the utilization of MFA:
- Controlling pathways for materials use and industrial processes
• Understanding of the industrial metabolism – requires a description of the most relevant material flows through the industrial economy
• Selection of relevant materials on the goods level and substance level
• System boundaries defined so that the pathways of materials are covered from the cradle to grave
• Detect relevant stocks in the economy and environment, show the losses and sinks - Creating loop-closing industrial practices
• The concept requires closed loops (industrial symbiosis)
• Requires information about the composition of wastes to become feedstock again and the characterization of the technological process involved
• The fact that waste is recycled or reused is not a guarantee for a poritive result, but can result in more pollutants and toxins being used - Dematerializing industrial output
• Can be achieved by providing functions or services instead of products
• Or also by prolonging the lifetime of products
• Or producing lighter goods - Systematizing patterns of energy use
- Balancing industrial input and output to natural ecosystem capacity
What 2 kinds of resources are there?
2 kinds of resources:
o Natural – minerals, water, air, soil, information, land, biomass (incl plants, animals, humans)
o Human-induced resources – the anthroposphere as a whole, incl materials, energy, information (science, art, tech, culture) and manpower
Located in:
- Private households, agriculture, industry, trade, commerce, administration, education, health care, defense
- Infrastructure and networks for supply, transportation and communication, and disposal
Due to the large-scale exploitation of mines and ores, many natural resources are massively transformed into anthropogenic resources, making the stocks growing in the anthroposphere increasingly more important as a resource in the future.
Why does anthropogenic flows surpass geological flows?
A consequence of constant increase in material exploitation due to the large per capita consumption is that the anthropogenic flow of certain substances already surpasses the geologic (natural) flow of substances. For some metals, the anthroposphere is about 3-4 times larger than the geogenic flow of erosion, weathering, and leaching -> concentrations will increase in some env compartments such as soil, leading to an unwanted legacy for future generations to costly manage
Why does material stocks grow fast?
o Because material inputs in growing regional economies are larger than outputs, most modern regions accumulate a large material stock within their boundaries. Exceptions are regions that exploit and export resources on a large scale (ex. coal, metal ores, timber)
o Stock in society needs to be maintained and managed, and some stock can range up to more than 100 years -< it will not show up quickly in the output
For the management of resources and the env, the urban stock is important for several reasons. Which 3?
- It is a growing reservoir of valuable resources and holds a big potential for future recycling
- It represents a mostly unknown source, whose importance is not yet in focus, which awaits assessment with respect to its significance as an economic resource and as a threat to the env
- It is a potential long-term source of large flows of pollutants to the env. Urban stocks contain more hazardous materials than so-called hazardous landfills
Objectives of MFA (5):
- Delineate a system of material flows and stocks by well defined terms
- Reduce the complexity of the system, why providing a basis for decision making
- Assess the relevant stocks in quantitative terms, applying balance and revealing sensitivities in system
- Present results about the flow and stocks in an understandable way
- Use the result as a basis for managing resources, the environment, and waste
