TOWARD A GREENER ANTHROSPHERE THROUGH INDUSTRIAL ECOLOGY

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CHAPTER 11 TOWARD A GREENER ANTHROSPHERE THROUGH
INDUSTRIAL ECOLOGY
From Green Chemistry and the Ten Commandments of
Sustainability, Stanley E. Manahan, ChemChar
Research, Inc., 2006 manahans_at_missouri.edu
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11.1. INDUSTRIAL ECOLOGY AND INDUSTRIAL ECOSYSTEMS
The anthrosphere has been defined as a fifth
sphere of the environment. Industrial ecology
integrates the principles of science,
engineering, and ecology in industrial systems
through which goods and services are provided in
a way that minimizes environmental impact and
optimizes utilization of resources, energy, and
capital
Every aspect of the provision of goods and
services from concept, through production, and to
the final fate of products remaining after
use A sustainable means of providing goods and
services Most successful when it mimics natural
ecosystems
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Industrial Ecosystem
An industrial ecosystem functions through groups
of industrial concerns, distributors, and other
enterprises functioning to mutual advantage,
using each others products, recycling each
others potential waste materials, and utilizing
energy as efficiently as possible to maximize
Market value of products
Consumption of material and energy
An industrial ecosystem is illustrated on the
following slide Industrial symbiosis is the
development of such mutually advantageous
interactions between two or more industrial
enterprises that cause an industrial ecosystem to
develop in the first place Required for
recycling
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Major Components of an Industrial Ecosystem
Showing Maximum Flows of Material and Energy
Within the System
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Scope of Industrial Ecology
Regional scope large enough to encompass several
industrial enterprises, but small enough for them
to interact with each other on a constant
basis Frequently based around transportation
systems such as segments of interstate highways
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11.2. METABOLIC PROCESSES IN INDUSTRIAL ECOSYSTEMS
Industrial metabolism refers to the processes to
which materials and components are subjected in
industrial ecosystems
Analogous to the metabolic processes that occur
with food and nutrients in biological systems
Industrial metabolism may be addressed at several
levels
Green chemistry at the molecular level where
substances are changed chemically to give desired
materials or to generate energy Within
individual unit processes in a factory At the
factory level At the industrial ecosystem
level Even globally

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Wastes and Industrial Ecology
Wastes in natural and industrial ecosystems In
natural ecosystems true wastes are virtually
nonexistent Waste plant biomass forms soil
humus Anthropospheric industrial systems have
developed in ways that generate large quantities
of wastes
Industrial waste may be defined as dissipative
use of natural resources. Human use of
materials has a tendency to dilute and dissipate
materials and disperse them to the
environment Materials may end up in a physical
or chemical form from which reclamation becomes
impractical because of the energy and effort
required A successful industrial ecosystem
overcomes such tendencies
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Minimization of Byproduct and Waste
The objective of industrial metabolism in a
successful industrial ecosystem is to make
desired goods with the least amount of byproduct
and waste Consider production of lead from lead
ore for the production of storage batteries
Mining large quantities of ore Extracting the
relatively small fraction of the ore consisting
of lead sulfide mineral Roasting and reducing
the mineral to get lead metal These processes
generate large quantities of lead-contaminated
tailings left over from mineral extraction and
significant quantities of byproduct sulfur
dioxide, which must be reclaimed to make sulfuric
acid and not released to the environment
The recycling pathway for lead production takes
essentially pure lead from recycled batteries and
simply melts it down to produce lead for new
batteries
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Comparison of Natural Ecosystems and Current
Industrial Systems
The basic unit of a natural ecosystem is the
organism, whereas that of an industrial system is
the firm Natural ecosystems handle materials in
closed loops whereas with current practice,
materials traverse an essentially one-way path
through industrial systems Natural systems
completely recycle materials, whereas in
industrial systems the level of recycling is
often very low Organisms have a tendency to
concentrate materials such as CO2 from air
concentrated in biomass whereas industrial
systems tend to dilute materials to a level where
they cannot be economically recycled, but still
have the potential to pollute. The major
function of organisms is reproduction whereas the
main function of industrial enterprises is to
generate goods and services
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Natural Ecosystems and Current Industrial Systems
(Cont.)
Reservoirs of needed materials for natural
ecosystems are essentially constant (oxygen,
carbon dioxide, and nitrogen from air as
examples) whereas industrial systems are faced
with largely depleting reservoirs of materials
(essential mineral ores) Recycling gives
essentially constant reservoirs of materials
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Regulation in Natural and Industrial Ecosystems
Biological systems have elaborate means of
control. Entire ecosystems are self-regulating. In
dustrial systems do not inherently operate in a
self-regulating manner that is advantageous to
their surroundings, or even to themselves. Failure
of self-regulation of industrial systems
Have wastefully produced large quantities of
goods of marginal value Running through limited
resources in a short time Dissipating materials
to their surroundings Polluting the environment
Industrial ecosystems can be designed to operate
in a self-regulating manner
Best under conditions of maximum recycling in
which the system is not dependent upon a
depleting resource of raw materials or energy
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Level of Recycling and Embedded Utility
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11.3. LIFE CYCLES IN INDUSTRIAL ECOSYSTEMS
In a system of industrial ecology the entire life
cycle of the product is considered as part of a
life-cycle assessment.
To determine, measure, and minimize
environmental and resource impacts of products
and services. Scope of the assessment Time
period Space Kinds of materials,
processes, and products in the assessment
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Example of Scope in Life Cycle Assessment
Example of the manufacture of an insecticide that
releases harmful vapors and generates significant
quantities of waste material
A narrowly focused assessment might consider
control measures to capture released vapors and
the best means of disposing of the waste
byproducts A broader scope would consider a
different synthetic process that might not cause
the problems mentioned An even broader scope
might consider whether or not the insecticide
even needs to be made and used perhaps there are
more acceptable alternatives to its use.
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Life Cycle Assessment
Inventory analysis to provide information about
the consumption of material and release of wastes
from the point that raw material is obtained to
make a product to the time of its ultimate
fate Impact analysis that considers the
environmental and other impacts of the
product Improvement analysis to determine
measures that can be taken to reduce impacts
In doing life-cycle assessments consider three
major categories
Products Things and commodities that consumers
use Processes Ways in which products are
made Facilities consisting of the
infrastructural elements in which products are
made and distributed
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Example of Life Cycle Assessment
Example of paper product
The environmental impact of paper product tends
to be relatively low. Even when paper is
discarded improperly it does eventually degrade
without permanent effect. Process of making
paper, beginning with harvesting of wood and
continuing through the chemically intensive
pulping process and final fabrication has
significant environmental impact
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Facilities
Highly variable impact of facilities Brownfields
to describe sites of abandoned industrial
facilities Challenge to decomission sites of
nuclear power reactors in which there is a
significant amount of radioactivity to deal with
in dismantling and disposing of some of the
reactor components Facilities can be designed
with eventual decommissioning in mind Structure
flexibility of commercial buildings
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Product Stewardship
Laser printer cartridges Automobile
batteries Disincentive of disposal fee for
automobile tires Leasing Deposits
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11.4. KINDS OF PRODUCTS
Consumable products such as laundry
detergents Recyclable commodities such as motor
oil Service products such as washing
machine Consumable products are dispersed to the
environment Nontoxic Not bioaccumulative
Degradable Recyclable commodities should be
designed with durability and recycling in mind
Not as degradable as consumables
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Service Products
Service products are designed to last for
relatively long times, but should be recyclable
Channels through which such products can be
recycled Proposed de-shopping centers where
items such as old computers and broken small
appliances can be returned for recycling Designe
d and constructed to facilitate disassembly so
that various materials can be separated for
recycling.
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11.5. ATTRIBUTES REQUIRED BY AN INDUSTRIAL
ECOSYSTEM
Key attributes of energy, materials, and
diversity Energy With enough energy, almost
anything is possible
Consuming abundant fossil energy resources
would cause unacceptable global warming
effects Solar energy and wind energy are
renewable sources of energy but are intermittent
nature and require large areas of land in order
to provide a significant share of energy
needs Nuclear power facilities can provide
abundant reliable energy, but present waste
problems
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Cogeneration and Combined Power Cycles

• Cogeneration employing combined power cycles
  (next slide) represents the most efficient energy
  use within an industry or within an industrial
  ecosystem
• (1) Electricity generation
• (2) Steam used in processing
• (3) Steam and hot water used for heating

Burning fuels in large turbines connected to an
electrical generator and using the hot exhaust
from the turbine to raise steam can double the
overall efficiency of energy utilization. Using
the cooled steam from the steam turbine for
heating can further increase the overall
efficiency of the energy utilization process.
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Combined Power Cycles
Combined power cycles use energy with great
efficiency through several levels as shown below
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Materials
Utilization of materials Dematerialization in
which less material is used for a specific
purpose Example Less copper in 12 volt
automobile electrical systems Substitution of
abundant materials for scarce ones Solid state
circuits in radios or televisions
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Recycling and Waste Mining
Recycling Wood and paper, which are not scarce,
but recycling is advisable Metals, especially
scarce and valuable ones such as chromium,
platinum, and palladium Parts and apparatus
that can be refurbished and reused Waste mining
Needed materials extracted from
wastes Combustible methane gas from municipal
refuse landfills Aluminum from finely divided
coal fly ash generated in coal combustion
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Diversity in Industrial Ecosystems
Diversity imparts a robust character to
industrial ecosystems, which means that if one
part of the system is diminished, other parts
will take its place and keep the system
functioning well
Example Diverse energy sources to reduce
vulnerability to interruptions in power and
energy supplies Example Diverse food sources
to reduce vulnerability to reliance on one food
source for diet
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The Kalundborg Industrial Ecosystem
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11.7. ENVIRONMENTAL IMPACTS OF INDUSTRIAL
ECOSYSTEMS
The practice of industrial ecology in the
anthrosphere affects the atmosphere, hydrosphere,
geosphere, and biosphere. Emission to the
atmosphere of pollutant gases, vapors from
volatile compounds, particles and greenhouse
warming carbon dioxide Large quantities of water
that may become polluted or warmed excessively
when used for cooling (thermal pollution). Disrupt
ion of the geosphere from mining, dredging, and
pumping of petroleum and other extractive
activities Detrimental effects to the biosphere
by release of toxic substances Greenhouse-warming
carbon dioxide emissions, acid gas emissions,
smog-forming hydrocarbons and nitrogen oxides,
and deterioration of atmospheric quality from
particles released from fossil fuel combustion
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Environmental Effects of Agricultural Activities
Some of the environmental effects of agricultural
activities include Replacement of entire,
diverse biological ecosystems with artificial
ecosystems, which causes a severe disturbance in
the natural state of the biosphere Loss of
species diversity Greenhouse-warming methane
from rice paddies and from livestock digestive
systems Slash and burn agricultural
techniques practiced in some tropical
countries Water used for irrigation, water
salinity Transgenic crops and livestock may
have profound effects
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Design of Industrial Ecosystems to Minimize
Environmental Impact
Recycling materials, especially those extracted
from the geosphere Selection of materials, such
as silica fiber optic cables in place of
copper Minimization of emission of volatile
organic compounds Complete water recycle Totally
eliminate wastes requiring land disposal Most
efficient use of the least polluting sources of
energy possible Design of buildings to reduce
heating and cooling costs Combined power cycles
along with the generation of electricity
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11.8. GREEN CHEMISTRY IN THE SERVICE OF
INDUSTRIAL ECOSYSTEMS
Total mass of product
Percent atom economy
Total mass of reactants
Use of nontoxic chemicals and processes Considerat
ion of the chemical reactions and processes by
which chemicals are manufactured
Use existing chemical synthesis processes but
make the process itself safer and less polluting
while also making the reagents required for it by
greener processes Use different reagents for
the synthesis that are safer and less likely to
pollute.

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Hazard Reduction
Exposure reduction has emphasized protective
measures At a personal level, safety
glasses At an industry level, end-of-pipe
measures, such as scrubbers on stacks Command
and control refers to regulations that apply
primarily to processes that have inherent dangers
or that produce pollutants. End-of-pipe
measures are applied to the removal of pollutants
and wastes that are produced in a process, rather
than their elimination within the process
itself. Green chemistry relies on hazard
reduction Know what the hazards are and where
they originate Toxicity hazards Hazards
associated with uncontrolled events such as fires
and explosions
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Toxic Substances
Toxic substances classified according to
biochemical properties that lead to toxic
responses
Structure activity relationships, which use
computer programs to find correlations between
features of chemical structure, such as groupings
of functional groups, and the toxicity of the
compounds Example Compounds containing the
N-NO functional group are N-nitroso compounds, a
family noted for members that cause cancer
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Chemicals to Eliminate in Reducing Toxicity
Hazards
Three kinds of chemicals have a high priority in
eliminating the toxicity hazards in green
chemistry
1. Heavy metals, such as lead, mercury, and
arsenic (a metalloid) 2. Lipid-soluble organics
that are not readily degraded and may undergo
biomagnification in moving through a food
chain 3. Volatile organic compounds (VOCs, below)
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Hazardous, Reactive Chemicals
Chemicals that pose hazards because of their
potential to undergo destructive chemical
reactions
Combustible or flammable substances Oxidizers,
such as ammonium perchlorate, NH4ClO4, that
provide sources of oxygen for the reaction of
reducers Reactive substances such as explosive
nitroglycerin 4C3H5N3O9 ? 12CO2 10H2O
6N2 O2 (11.8.1) Corrosive
substances that attack materials, including even
human flesh because they are strong acids, bases,
or oxidizing agents
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11.9. FEEDSTOCKS, REAGENTS, MEDIA, AND CATALYSTS
The main components of a chemical
process Feedstocks that are converted to final
product Reagents that act upon
feedstocks Media in which reactions
occur Catalysts that enable reactions to occur
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Feedstocks
Three major components of the process by which
raw materials from a source are obtained in a
form that can be utilized in a chemical synthesis
1. Source of the feedstock
Depleting resource, such as petroleum Recycled
materials Renewable resources, particularly
from materials made by photosynthesis and
biological processes.
2. Separation and isolation of the desired
substance
Often the most environmentally harmful because
of the relatively large amount of waste material
that must be discarded in obtaining the needed
feedstock.
3. Chemical processes that give the final product
by reactions upon feedstocks by various kinds of
reagents in media such as organic solvents, often
using catalysts.
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Reagents
A reagent is a substance that converts feedstocks
to new chemicals High product selectivity
High product yield Alternative reagents are often
important in green chemistry
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Oxidation and Oxidation Reagents
Oxidation reagents add oxygen to a chemical
compound or a functional group on a
compound Example
Oxidation often uses dangerous reagents, such
as potassium dichromate, K2Cr2O7 Green
chemistry tries to use safer molecular oxygen
(O2), ozone (O3), and hydrogen peroxide (H2O2)
usually used with a suitable catalyst or
catalyzed by enzymes Organisms carry out
biochemical oxidations under mild conditions
using monooxygenase and peroxidase enzymes that
catalyze the oxidizing action of molecular oxygen
or hydrogen peroxide
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Reduction
Reduction consisting of loss of O, gain of H, or
gain of electrons Hazardous reductants such as
lithium aluminum hydride (LiAlH4) and tributyltin
hydride.
Electrical currents can be used for oxidation and
reduction without reagents
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Alkylation
Alkylation for attachment of alkyl groups
especially -CH3 Commonly performed with
dimethyl sulfate reagent
Dimethyl sulfate
Dimethyl sulfate may be carcinogenic As an
alternative, use dimethyl carbonate
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Media
Media in which reactions occur Usually organic
solvents or water Provide a medium in which
feedstocks and reagents can dissolve and come
into close, rapid contact at the molecular
level Water is safest, but may not work for
organic materials Hydrocarbon solvents may
burn, explode or be toxic Replace solvents with
less hazardous ones, such as benzene (which may
cause leukemia) by toluene
Replace straight-chain hydrocarbon n-hexane,
which can cause peripheral neuropathy, with
branched-chain 2,5-dimethylhexane, which is not
very toxic Nonpolar organic solvents suspended as
colloidal particles can be used as
media Supercritical carbon dioxide at high
pressure and elevated temperature can act as media
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Ionic Liquids
Ionic liquids such as the one shown below have
been used as media for some reactions
Solvent-free reactions have been used with some
success
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Catalysts
Catalysts are substances that speed reactions
without being consumed themselves Heterogeneous
catalysts that are held upon some sort of support
where they interact with reactants Readily
separated from reaction products Homogeneous
catalysts that are actually mixed with the
reactants Often work better because of intimate
contact with reagents Require separation and
may contaminate product An objective of green
chemistry is to develop heterogeneous catalysts
that equal homogeneous catalysts in their
performance
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Enhancement of Catalyst Selectivity
Selectivity enhancement of catalysts is
desirable Lower energy requirements and less
severe, safer conditions with appropriate
catalysts Enzyme-catalyzed green chemical
processes including those with transgenic
organisms Synthetic catalysts that mimic enzyme
action such as the one shown below that mimics
iron-based enzymes