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Corollary 3: Maintaining quality is synonymous with e
ciency. Therefore,
losses in quality must be monitored, maintaining the necessary specifications
for the product. Do not mix, purify, clean, heat, cool, pressurise or depressurise
more than strictly necessary. Any additional excess just becomes more and
more costly.
Corollary 4: Segregate polluting flows; do not mix them.
Corollary 5: The more advanced a product is in its productive process, the
higher its cost and the more energy is rended useless with its loss. Never let a
product degrade.
Reflection 1: The Second Law should be at the forefront of any society based
on resource e
ciency with an economy founded on materials. In agreement with
this Law, a linear increase in specifications implies an exponential one in the energy
required to obtain it. Likewise, ever larger quantities of water and materials are
used. Excessive use of any resource is unsustainable and even unreasonable, es-
pecially if it is a reckless enjoyment of “wants” which prevents others from having
what they really need. Energy, materials and water must be supplied as “fit for
purpose”. Many industrial operations use freshwater, some of which really don't
require it. Water in industrial and mining operations should only be treated to the
point of being useful for the work it is destined to do. Appropriate material use
reduces losses and can facilitate recycling and/or re-use. A proper management
of energy, meanwhile, would ensure that any inputs are carefully calibrated with
the exact temperature and pressure required process by process. Any excess that
cannot be prevented should where possible, be recirculated and used in steps which
do not require extremely high temperatures but do need an input of heat or low
quality steam. Entropic changes must also be reduced to the minimum amount
possible especially as the production chain grows larger and more complex from
cradle to grave. This can be done through methods such as energy cascading and
Pinch analysis, including Water Pinch analysis (see Principle 3).
Reflection 2: These corollaries apply to many separating operations and find
obvious use in any recycling process. If, in trying to separate the metal consti-
tuents from a recyclate, one does not invest enough exergy, one would then only
obtain the “paying metals” from a very entropic mixture. Separating all metals
completely, however desirable in terms of material preservation, would require ex-
ponential amounts of exergy that simply would not pay financially, leading to yet
more potentially useful resources being converted into waste. Moreover, waste in-
creases with the irreversibility of product manufacture, that is to say as waste
volumes grow so does the corresponding difference between exergy and exergy cost
(Sec. 14.7 and Sec. 14.4).
Reflection 3: Since the cost increases with the productive chain of a given pro-
duct, end-user consumption should be the main focus of our present economy. A
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