Industrial Metabolism: Theory and Policy Robert U. Ayres

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Industrial MetabolismTheory and PolicyRobert
U. Ayres

• Summary Patrick Wilkinson
• Critique James Silva

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Overview

• Introduction to Industrial Metabolism
• The Materials Cycle
• Measures of Industrial Metabolism
• Policy Implications of the Industrial Metabolism
  Perspective

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Introduction to Industrial Metabolism

• Definition the whole integrated collection of
  physical processes that convert raw materials and
  energy, plus labor, into finished products and
  wastes in a (more or less) steady-state
  condition.
• Metabolism Analogous to the process of a living
  organism
• Takes in food for self/storage and excretes
  wastes.
• Differences
• Organisms reproduce themselves, specialized,
  change over long period of time.
• Firms produce products or services, not
  specialized, can change quickly

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The Materials Cycle

• Closed cycles are self-sustaining with no
  external sources or sinks and are in steady
  state.
• Open cycles are unsustainable, using materials
  without replenishing sources.
• Must stabilize or will ultimately fail
• The Biological cycle is a closed cycle, while
  our industrial cycle is an open cycle.

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The Material Cycle

• Industrial system of today Unsustainable
• Can this stabilization be obtained with a
  technological fix?
• If so, how?
• If not, how long will the current system last?
• Biological system
• Has not always been a closed system
• Responded to inherently unstable situations
  (open cycles) by inventing new processes
  (organisms) to stabilize the system by closing
  the cycles.
• Time scales
• Biological system took billions of years
• Industrial system does not have that much time

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Measures of Industrial Metabolism

• Recycling and dissipative loss are the fates of
  all waste materials
• There are 3 classes of materials use
• Those that are recyclable under present
  technology and cost
• Those that are recyclable, but not under present
  tech. and cost
• Those that are not recyclable
• For the industrial system to function as a closed
  cycle, it must recycle or reuse nearly all
  materials

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Measures of Industrial Metabolism

• Examples of dissipative use Class 3 materials
• Sulfur
• CFCs
• Ammonia
• Phosphoric acid
• Chlorine
• Although can be classified as class 2 when used
  in plastics and solvents

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Measures of Industrial Metabolism

• Potentially recyclable materials
• Are they being recycled and reused?
• Recycle (reuse) vs. Dissipation of a material
  shows how far sustainability is from being reached

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Policy Implications of the Industrial Metabolism
Perspective

• Industrial metabolism is holistic in theory
• All interactions are considered together
  resulting in the best for the system as a whole
• Short term solutions and policies, however, are
  being enforced
• Such policies are usually more harmful and costly
  in the long run
• Ex.s Pollution and coal as a fuel
• Air and water pollution reduced, but land
  disposal increased
• Clean coal technology could extend coal as fuel,
  but effects of byproducts extended as well

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Critique

• Sulfur Example
• Comparison human vs. natural
• Material Source vs. Material Path
• A more holistic view

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Sulfur Example

• Example of Dissipative use
• Nearly all sulfur mined is dissipated or
  discarded
• Mostly used for sulfuric acid used in
  non-recyclable chemicals
• Thus sulfur mainly falls into the third category
• But plaster-of Paris

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Comparison human vs. natural

• Where is the natural to compare with the
  anthropogenic?
• What are the percentages referring to?
• In all cases, with the possible exception of
  nitrogen, the anthropogenic contributions exceed
  the natural flows by a considerable margin.
• Really?

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Comparison human vs. natural (Can you interpret
this?)
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Material Source vs. Material Path

• Should be less concerned with how much of
  something is left than with what path used
  material takes
• How much oil/steel/etc. is left to be extracted
  from natural sources is not a good measure of
  evaluation for industrial processes
• A better way is to quantify how much recycling of
  material is going on What do we do with what we
  use?

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A more holistic view

• Defines it more by what it is not
• Contrasts with narrowly conceived or short-run
  (myopic) quick fix policies
• Longer pipelines for sewage
• Air vs. water vs. land
• Not an in-depth application paper
• Less than 15 pages
• The industrial system of tomorrow?

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Questions?