Leslie W. Ayres

A Handbook of Industrial Ecology

Industrial ecology is coming of age and this superb book brings together leading scholars to present a state-of-the-art overviews of the subject. Each part of the book comprehensively covers the following issues in a systematic style: the goals and achievements of industrial ecology and the history of the field; methodology, covering the main approaches to analysis and assessment; economics and industrial ecology; industrial ecology at the national/regional level; industrial ecology at the sectoral/materials level; and applications and policy implications.

Exergy, power and work in the US economy, 1900–1998

Conventional economic growth theory assumes that technological progress is exogenous and that resource consumption is a consequence, not a cause, of growth. The reality is different and more complex. A ‘growth engine’ is a positive feedback loop involving declining costs of inputs and increasing demand for lower priced outputs, which then drives costs down further, thanks to economies of scale and learning effects. In a competitive environment prices follow. The most important ‘growth engine’ of the first industrial revolution was dependent on coal and steam power. The feedback operated through rapidly declining fossil fuel and mechanical power costs. The advent of electric power, in growing quantities and declining cost, has triggered the development of a whole range of new products and industries, including electric light, radio and television, moving pictures, and the whole modern information sector. The purpose of this paper is to reformulate the idea of the ‘growth engine’ in terms of the service provided by energy inputs, namely ‘useful work’, defined as the product of energy (exergy) inputs multiplied by a conversion efficiency. We attempt here to reconstruct the useful work performed in the US economy during the twentieth century. Some economic implications are indicated very briefly.

The life cycle of copper, its co-products and byproducts

1. Introduction.- 2. Copper: Sources and Supply.- 3. Copper: Demand and Disposition.- 4: Lead, Zinc and Other Byproduct Metals.- 5. The Future of Recycling.- 6. Conclusions and Questions.- References.- Appendix A: The Exergy Concept.- A1. Definition and description of exergy calculations.- A2. Exergy as a tool for resource and waste accounting.- A3. Composition of mixtures, including fuels.- Appendix B: The Behavior of Copper, Lead and Zinc in Soil.- B1. Metals in soils.- B2. Aqueous phase speciation.- B3. Solid phase constituents and complex formation.- B4. Summary.- Appendix C: Global Copper Model.- C1. Introduction.- C2. A model of the global copper system.- C3. Calibration of the model.- C4. Copper consumption scenarios.- C5. Copper system scenarios.- Appendix D: Glossary.

The Life‐Cycle of Chlorine, Part IV

Some cyclic organo‐chlorines share key characteristics to a significant degree, notably volatility, solubility in lipids, environmental persistence, a tendency to bioaccumulation, and toxicity to animals. A subset of this group has been designated “persistent organic pollutants” (POPs). Because of their volatility, persistence, and tendency to bioaccumulate, POPs are found in remote locations, such as the Arctic, far from the locations where they were initially used or produced. Except PCDDs (dioxins) and PCDFs (furans), all are, or were, originally produced for use as such, mainly as pesticides or herbicides. PCDDs and PCDFs have never been produced for their own sake; they are unwanted contaminants of chemical intermediates that were passed on and incorporated in final products, notably herbicides; they are also generated spontaneously in most combustion processes and chlorine bleaching of paper. Most POPs have been sharply restricted or banned outright in most of the industrialized countries, but not in less developed countries. The qualities of persistence and bioaccumulation give special urgency to monitoring not only point source emissions and local concentrations, but also the mobile environmental reservoirs and exposure routes of these chemicals. To conduct adequate risk analyses, far more detailed data is needed on quantities produced and used, quantities and location of storage, mode of use, location of use, and period of use. Such data are not collected consistently by government or international agencies.

The Future of Recycling

It is well-known that the most (only) dynamic and profitable sector of the US steel industry is the so-called ‘mini-mills’ — exemplified by Nucor. These companies are essentially scrap processors and recyclers. At first they produced mainly rather low grades of steel products from iron and steel scrap. It is authoritatively estimated that 95 percent of the iron and steel embodied in products eventually returns as old scrap (Sibley et al. 1995). In recent years the recycling technology has improved significantly, and with it the quality of the products and the range of products in which recycled steel can be used. In the long run, as steel recycling technology improves further and global demand approaches saturation, it would seem that the so-called ‘integrated’ iron and steel producers, who start from iron ore, are facing gradual extinction, at least in the industrialized countries.

Conclusions and Questions

In this section we note the major conclusions and implications of the study, without attempting to summarize each chapter in detail. We consider long term supply, recovery technology, usage (and possible substitutes), recycling and environmental impact, in that order.

Lead, Zinc and Other Byproduct Metals

Just as metals are rarely found in pure form, the same is true of minerals. Moreover, certain combinations are apparently preferred by nature. That is to say, certain minerals tend to be found together or in each other’s ores. This is especially true of the sulfide ores of heavy metals. Lead and zinc (and a number of other metals, discussed in this chapter) are almost invariably found in copper ores (in trace amounts, to be sure) and conversely. Most lead mines also produce zinc, and conversely. Molybdenum, nickel and cobalt are also commonly found with copper, though copper is generally a byproduct of these metals and not the primary product.

Copper: Sources and Supply

Copper has atomic number 29, belongs to the same group (1B) as silver and gold, and shares some of their properties, including color, high electrical and thermal conductivity, high ductility (making it easy to draw into wire) and high malleability. Copper is second only to silver in electrical and thermal conductivity, and is significantly better than the third and fourth highest metals in both categories (gold and aluminum, respectively). Copper is also relatively corrosion resistant, although it does oxidize slowly in air. It has a high melting point (1083 C), with specific heat of 0.39 kJ/kg per degree C, and its melting heat is 343 kJ/kg, whence the theoretical heat requirement for melting pure copper is less than for competing metals such as iron and aluminum. It has a very high boiling point (2595 C) and has a very low tendency to fume, as compared to other non-ferrous metals such as arsenic, cadmium, lead, and zinc.

Copper: Demand and Disposition

As noted already in the historical introduction, the modern industrial era began with the advent of the electric telegraph and the associated use of copper wire. Telegraph lines and undersea cables were the initial users, followed in the 1880s by electric power generating and distribution systems, which grew even more rapidly.