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“Composed thermodynamic rarity” of the materials in electric and electronic equipment

Abstract:

We undertake thermodynamic assessment of some industrial techniques that are widely regarded as being characteristic of a presumed 21st-century “green economy.” We assess various mineral commodities in terms of their “thermodynamic rarity,” defined as the amount of exergy that has to be spent (for a desired amount) in order to get and purify them to the desired extent from ordinary rock (i.e. not from ore), using the best prevailing techniques. With this concept one can take into account both (a) the expenditures of consumable energy associated with the mining, beneficiation and purification processes and (b) the natural bonus of having access to concentrated mineral deposits (ores) in the first place. While thus defining a thermodynamically rare chemical element as one that is scarce and/or costly (in terms of energy) to process, we assess the “composed thermodynamic rarities” of the stuff used in various kinds of electric and electronic equipment (EEE). The results show that apparently EEE are often inefficient in terms of the materials used for their production.