Industrial ecology (IE) is the study of material and energy flows through industrial systems. The global industrial economy can be modelled as a network of industrial processes that extract resources from the Earth and transform those resources into by-products, products and services which can be bought and sold to meet the needs of humanity. Industrial ecology seeks to quantify the material flows and document the industrial processes that make modern society function. Industrial ecologists are often concerned with the impacts that industrial activities have on the environment, with use of the planet's supply of natural resources, and with problems of waste disposal. Industrial ecology is a young but growing multidisciplinary field of research which combines aspects of engineering, economics, sociology, toxicology and the natural sciences.
Industrial ecology has been defined as a "systems-based, multidisciplinary discourse that seeks to understand emergent behavior of complex integrated human/natural systems". The name comes from the idea that the analogy of natural systems should be used as an aid in understanding how to design sustainable industrial systems. Frosch and Gallopoulos' vision was "why would not our industrial system behave like an ecosystem, where the wastes of a species may be resource to another species? Why would not the outputs of an industry be the inputs of another, thus reducing use of raw materials, pollution, and saving on waste treatment?"
- Using second generation biofuels. An example of this is converting grease or cooking oil to biodiesels to fuel vehicles.
- South Africa's National Cleaner Production Center (NCPC) was created in order to make the region's industries more efficient in terms of materials. Results of the use of sustainable methods will include lowered energy costs and improved waste management. The program assesses existing companies to implement change.
- Onsite non-potable water reuse
- Biodegradable plastic created from polymerized chicken feathers, which are 90% keratin and account for over 6 million tons of waste in the EU and US annually. As agricultural waste, the chicken feathers are recycled into disposable plastic products which are then easily biodegraded into soil.
- Toyota Motor Company channels a portion of the greenhouse gases emitted back into their system as recovered thermal energy.
- Anheuser-Busch signed a memorandum of understanding with biochemical company Blue Marble to use brewing wastes as the basis for its "green" products.
- Enhanced oil recovery at Petra Nova.
- Reusing cork from wine bottles for use in shoe soles, flooring tiles, building insulation, automotive gaskets, craft materials, and soil conditioner.
- Darling Quarter Commonwealth Bank Place North building in Sydney, Australia recycles and reuses its wastewater.
- Plant based plastic packaging that is 100% recyclable and environmentally friendly.
- Food waste can be used for compost, which can be used as a natural fertilizer for future food production. Additionally, food waste that has not been contaminated can be used to feed those experiencing food insecurity.
- Hellisheiði geothermal power station uses ground water to produce electricity and hot water for the city of Reykjavik. Their carbon byproducts are then injected back into the Earth and calcified, leaving the station with a net zero carbon emission.
Future directions
The ecosystem metaphor popularized by Frosch and Gallopoulos For industrial ecology, this may mean a shift from a more mechanistic view of systems, to one where sustainability is viewed as an emergent property of a complex system.