Cradle to Cradle: Transitioning from Waste Incineration to Beneficial Materials
By Dr. Michael Braungart, Supervising Author
Issue 3 Spring 2010
Mixed waste incineration, often referred to as “Waste to Energy,” “energy recovery,” or “thermal treatment” is widely recognized as a promising ‘green technology.’ These new incinerators burn waste to create alternative energy in the form of electricity and are growing in abundance around the world, In reality, however, “Waste to Energy” contributes to environmental degradation and climate change at levels far beyond the short-term benefits gained from producing secondary fuel. “Waste to Energy” is literally wasting valuable resources by exacerbating raw material shortages and intensifying the loss of CO2-capturing topsoil. It also prevents effective recycling solutions due to competition for high-caloric recyclable content. In this article, scientists working with Prof. Michael Braungart through EPEA develop a Cradle to Cradle strategy for transitioning from “Waste to Energy” to a more effective strategic design: re-capturing beneficial materials that encourage true recycling instead of downcycling, and re-designing products so their materials can be recovered effectively.
The Current Situation
Waste incineration as practiced today is a low-quality, end-of-pipe technology, requiring a new cradle to cradle design strategy. The process of burning waste through incineration is widely used in many countries around the world. Recently, a new type of commercial waste incineration has gained in popularity, based on a concept called “Waste to Energy.”
Under the umbrella of “green energy” generation, these new waste treatment facilities burn waste to create secondary fuel, offering an alternative to primary energy sources, such as coal.
This secondary fuel, also known as “Residue Derived Fuel” (RDF), is a mix of household, industrial and commercial waste, conditioned for extracting high caloric value to increase its electricity generation potential. Unfortunately, the demand for “Waste to Energy” fuel is increasing as more incinerators are built. To feed the industry’s appetite, more and more valuable materials are used as RDF, consequently sending the entire waste stream, including nutrients for recycling to the plants. Over time, this has created a significant overcapacity of incineration facilities in places such as northern Europe, generating a suction effect for materials that are otherwise recyclable.
Secondary Fuel – Wasting Nutrients
This new “Waste to Energy” paradigm fails to consider the high nutrient value of waste or the hazardous impacts of burning them for cheap fuel. Through incineration, we are throwing away exhaustible raw materials, along with the energy needed to mine natural resources and manufacture them into consumable products. With this approach, not only do we lose valuable nutrients, we also create an aggressive disincentive for materials’ reuse.1 This is proven by the fact that the rates of recycled waste have not increased in the last few years despite the availability and high potential of recycling technologies 2.
Many governments seem to have forgotten that material recycling is essential for solving the increasing scarcity of raw materials on the world market. Setting policies that issue renewable energy tax credits to “Waste to Energy” incinerators only makes matters worse. In this way, a standard end of pipe paradigm has been set for the next 20 years, representing the lifetime of these facilities. Our society has established a paradigm of self-impoverishment in natural resources.1, 3
Shortage of Rare Metals
Worldwide consumption of raw materials is unsustainable at its current pace. Loss of natural forests to agricultural land exceeds 5-7 million hectares globally per year.4,5,6 Oil, uranium, heavy metals and phosphate have already been the subject of numerous wars, and in the last ten years, the use of many rare metals has accelerated at an alarming rate. For example, indium is being used in unprecedented quantities for making LCDs on flat-screen TVs and tantalum is used to make compact electronic devices like cell phones, and hafnium used to make computer chips. Global indium and hafnium reserves are estimated to last 10 years at best. Indium’s impending scarcity can already be reflected in its price: in January 2003 the metal sold for around $60 per kilogram; by August 2006 the price had risen to over $1000 per kilogram, leveling off at a modest $700 per kilogram in September 2009.7
Another telling example is the metal gallium, which along with indium is used to make indium gallium arsenide. This is the semi-conducting material at the heart of a new generation of solar cells. Reserves of both metals are disputed, but the current estimation would inhibit these cells from substantially contributing to the future supply of solar electricity. In fact, estimates show that gallium and indium will probably factor less than one per cent of all future solar cells, a limitation imposed purely by a lack of raw material. Without more aggressive recycling initiatives, antimony, which is used to make flame retardant materials, will run out in 15 years, and silver in 10 years. Zinc, which is important for the human immune system, could be exhausted by 2037. Finally, terbium, which is used to make the green phosphors in fluorescent light bulbs, could run out before 2012. Even reserves of such commonplace elements as copper, nickel and phosphorus used in fertilizer might run out in the not-too-distant future, given current rates of consumption.7
Without more aggressive recycling initiatives, antimony, which is used to make flame retardant materials, will run out in 15 years, and silver in 10 years.
Unfortunately, the recycling rate of most of these metals is very low. Hardly any indium, tantalum or gallium is recycled, and as a result, these essential nutrients find their way to incineration plants or landfill sites and are lost indefinitely. Therefore, we are creating a material problem that is much more imminent than our perceived energy shortage.1, 2, 4 For these reasons, a focus on designing high-quality materials recovery is the sensible path.
Waste Does not Burn When Most Nutrients are Removed
The heating value of waste depends on ‘hi-caloric’ fractions like paper, plastics and organics, which create the high temperatures necessary for effective secondary fuel generation. When these are removed from the incineration stream, through appropriate product design and proper material flow management for separation and recycling, there is no appreciable heating value of the residual waste.
In fact, by removing most materials like paper, wood, plastics, and textiles out of the waste stream, more than 80 percent of the heating value is lost. This suggests that incineration is not only a barrier to effective recycling, it is also an obsolete option.1
“Waste To Energy” Inhibits the Nutrient Cycle and Blocks Innovation
Many environmentally and ecologically sound recycling technologies exist today, and many additional methods are being developed to process biological and technical nutrients, such as non-ferrous metals more effectively. Copper, for instance, has high recycling potential and is especially important for use in electronics because of its electrical conductivity. The copper content in incineration slag averages 0.64 percent, and scientists are exploring ways to economically recover these high levels in spite of the complexity of slag. Comparatively, the total copper content in natural ore also averages less than one percent1 and involves an intensive mining process. Even as the copper “reserves-to-production” ratio is estimated at 32 years, the worldwide recycling rate of copper is down to only 10 percent).8,9 Plastic materials offer another telling example, where roughly 55 percent of all plastics are burned for energy recovery, rather than recycled for re-use.10 The increasing “Waste to Energy” thermal treatment trend eclipses advances in recovery techniques, blocking the necessary innovations for top quality recycling of plastics, paper and biological waste treatment, as well as the design for recovery of biological and technical nutrients.1
“Waste To Energy” Incineration as “Renewable Energy” Claims Are Deceptive
Recent research discredited claims that incineration produces “green” and “renewable” energy by demonstrating that some standard “Waste to Energy” incinerators produce more carbon dioxide from fossil fuels (such as plastics in rubbish) than a gas-fired power station.11 The independent study shows that electricity-only incinerators currently produce 33 percent more fossil fuel derived CO2 per unit energy generated than a gas fired power station. By 2020, with increases in recycling and improved technology, these incinerators will pollute almost as heavily in terms of CO2 emissions as new or refitted coal-fired power stations, and 78 percent worse than new gas-fired power stations.12
Friends of the Earth summarized the situation this way: “The Government and waste industry must stop peddling the myth that waste incineration is green or renewable energy. Incinerators can generate electricity, but they produce more climate emissions than a gas-fired power station. The Government must make it clear that they will not support the building of such polluting plants. Using these incinerators to produce energy will undermine Government attempts to tackle climate change. Ministers must back truly renewable energy sources instead.”13
The energy balance of incineration plants shows they may be more properly termed “Energy-Wasting” plants.1, 14 An energy balance of a facility must include energy required for plant construction, and energy required for substitute fuel production and refining. Taken together with primary energy input, auxiliary power and loss of heat, secondary fuel facilities clearly need more energy input than they produce.
Available solar income is more than a thousand fold greater than our present energy needs
The calculations in Figure 3 illustrate that the world does not have an energy problem that necessitates combustion of waste for generating energy. Available solar income is more than a thousand fold greater than our present energy needs.15 The decisive factor is the right “energy-harvesting technology.” The technology to harvest solar energy and other renewable energy sources is widely accepted and rapidly being developed worldwide. Creating cheap fuel from waste is not required to supplement solar income, and instead interferes with strategic allocation of energy investments.1
Incineration Worsens the Co2 Problem
Incineration of bio-waste also hinders topsoil production. Compost is essential for humus production and for rebuilding topsoil that sequesters CO2. More than twice as much CO2 is bonded in soil and biomass as in the atmosphere.16 (See atmosphere and soil quantities in Figure 2).
The Government and waste industry must stop peddling the myth that waste incineration is green or renewable energy. Incinerators can generate electricity, but they produce more climate emissions than a gas-fired power station.
In the last 200 years, industrial countries lost approximately 50 percent of their topsoil due to various factors including industrial agriculture processes. Because of its high incineration capacities, bio-waste is not separately collected and composted or digested in many countries, including many parts of Germany. Therefore, these essential materials are lost to the nutrient cycle and the topsoil production process.1, 17
Strategy for Transitioning from Incineration to a Cradle To Cradle Economy
Despite many available technologies to effectively recycle materials, most products on the market such as paper, plastics, and non-ferrous metals and their ingredients are not designed for nutrient recovery. Those products contain multiple additives, which are sometimes harmful either to the environment or to humans and other organisms. Low-quality materials with various additives inhibit the reuse or recycling of their nutrients as post-consumer products,1 which motivates businesses to simply incinerate the materials to get rid of the problem. Despite a recent temporary drop in prices of resources and recycled materials from 2008 to 2009, the persistent trend is clear. Prices of resources are increasing as they become more difficult and expensive to extract from the natural environment.
This price increase opens a door to a new Cradle to Cradle® (See illustration full-size in Previous Themes Issue 3 PDF) economy, where companies can gain internal profits from recovering beneficial materials from products. The steps to achieving profitable cradle to cradle metabolisms are summarized here:
1 Establish nutrient pathways for ingredients, materials and products so they can be used as biological or technical nutrients.
2 Rematerialize biological nutrients to simultaneously generate energy and reusable materials. Sample metabolism processes include biodigestion, composting, fermentation, and gasification, which factor in CO2 sequestration, humus regeneration and reuse for fertilizing.
3 Establish Preference Lists (P-Lists) for chemicals and materials in industrial products so they can either be safely released into the biosphere, recycled effectively at the same quality level instead of down cycled, or down cycled in safe and defined pathways which lead back to biological metabolisms.
4 Design for assembly and disassembly to make products as technical nutrients that can be easily put together and taken apart.
5 Establish dedicated collecting logistics and recycling lines that profitably separate and recover resources from pre- and post-consumer products.
6 Celebrate diversity and design systems for regions with differing infrastructures and materials requirements.
7 Establish new supply chain partnerships, such as open mechanisms for cross-link cooperation, materials pooling between
different industries and exchanging innovations in individual industries. The combination of those strategies rather than any one single approach produces a profitable result for recycling resources.
Waste Incineration can be a Transition Technique Only if Narrowly Defined
“Waste to Energy” incineration is only ecologically worthwhile as a transition technique for products that cannot be recycled. In such cases, it is important to establish energy recovery from the high caloric fraction thermal treatment and limit it to cases where a defined transition strategy is underway.
If thermal treatment is necessary to incinerate poorly designed products that are not recyclable, then modular “Waste to Energy” facilities provide the preferred option as an interim solution. A modular facility starts with a module for mechanical treatment of waste fractions followed by several combustion modules. These modules can have the same capacity as combustion chambers of conventional incinerators, but the big advantage is more flexibility with several small combustion modules. The benefit is that the system need not rely on huge amounts of waste as in conventional systems. A modular organization has the ability to adapt to the available fuel.
Waste incineration is an end-of-pipe technology based on the Cradle to Grave paradigm. It is not the best solution for energy recovery or waste disposal, and if set as a standard, it will inhibit all efforts for material cycles. The preferred pathway is an effective product-design concept involving optimal separation in biological and technical nutrients and complete reuse of materials at the same quality level. Recovery of nutrients such as phosphorous, metals, and essential elements is necessary to a sustainable industrial system in the 21st Century.
STRATEGIES IN ACTION:
Establish nutrient pathways for ingredients,materials and products so they can be used as biological or technical nutrients
Rematerialize biological nutrients
Establish Preference Lists (P-Lists) for chemicals and materials
Design for assembly and disassembly
Establish dedicated collecting logistics and recycling lines
Establish new supply chain partnerships
About the Authors:
Dr. Tanja Scheelhaase
EPEA Internationale Umweltforschung
Dr. Michael Braungart is a chemist and cofounder of Cradle to Cradle® Design and MBDC McDonough Braungart Design Chemistry in Charlottesville, Virginia. He has pioneered a new paradigm in which humans can create a positive ecological footprint by redesigning products and systems to support a life-cycle economy.
Dr. Braungart developed the Cradle to Cradle® framework as a tool to help businesses redesign using renewable biological and technical pathways. He is the scientific director of Environmental Protection Encouragement Agency (EPEA) Internationale Umweltforschung GmbH and continues to lecture at universities around the world.
Co-author and Editor, Senior Researcher, Cradle to Cradle Chair, Erasmus University
Co-Author, EPEA Internationale Umweltforschung
Co-Author, EPEA Internationale Umweltforschung
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