by Stephen Lester
The BC Utilities Commission has instructed BC Hydro to search for low cost proposals to provide power for Vancou- ver Island. Entrepreneurs have floated a dozen proposals, from burning garbage in Nanaimo to burning coal near Campbell River. The Norske Canada pulp mills are all applying to expand their current practises of burn- ing coal, treated railway ties, and tires.
This burning attitude has emerged across the western world. In eastern Canada, Ben- nett Incineration, after unsuccessful tries in BC, has persisted with their attempts to burn toxic waste in northern Ontario and in New Brunswick.
In this article, the Center for Health, Environment and Justice reminds us that incineration by any other name is still incineration and it still produces toxic waste.
Grassroots groups have been very successful in defeating incin- erator proposals. Since 1997, only two trash incinerators have been built in the US. Groups have been successful because they organized and got the word out about what incinera tion really means for com munities: toxic emissions and residual ash, high construction costs, and the destruction of valu- able resources. And they have successfully promoted the alterna tives to burning waste: recycling, composting, and recovering waste com- ponents. The incinerator industry has, in fact, learned something from the successes of grassroots community groups: If they want to build incinera- tors, they’re going to have to come up with a new way to spin them. So what we’re seeing are all sorts of “new” ideas and proposals. The hottest area of activity is in plants designed to produce energy. Strong sentiments to reduce US de- pendence on foreign oil have resulted in a rash of proposals to build energy- generating plants that don’t rely on oil. Many of these plants are referred to as “green energy” or “eco-energy” projects. Some are called “renewable energy” projects. To a lesser extent, we are seeing an old favourite— waste-to-energy plants. Waste-to-energy projects are especially devious because there are legislative efforts to defi ne garbage incinerators as a source of “renew- able” energy. If these efforts are suc- cessful, the most common incinerator used to burn household garbage—the mass burn incinerator—will be in- cluded with solar and wind projects as renewable energy sources! These new proposals have sev- eral common characteristics: they are being put forward to solve the solid waste “crisis”; they are being sold as an alternative to incineration; and many recover energy. While these plants are not technically incinerators, they cause many of the same pollution problems. The old rule still applies: If it looks like a duck, walks like a duck, and sounds like a duck, there’s a good chance it’s a duck.
Biomass Conversion
One of the most popular renew- able energy projects is the “energy from biomass” proposal. Biomass tra- ditionally refers to fuels derived from wood, agriculture and food-process- ing waste or from crops grown specif- ically to produce electricity. However, in this new wave of non-incineration proposals, we’re seeing a variation that involves converting household trash into a biomass–like fuel. After sorting, the remaining waste, con- sisting largely of mixed paper, food, wood and yard waste, is run through a “biomass” conversion process that generates a fuel product. Some proposals are designed to generate ethanol and to sell it. The concern here is purity of the ethanol product. Historically, bioconversion processes have been used mostly with agricultural waste streams that are more uniform in composition, have higher cellulose content and fewer material handling problems than municipal solid waste streams.
The more common fuel product proposed with most biomass plants is called “refuse derived fuel” or RDF. In this instance, the biomass waste is converted into pellets that are sold as fuel to be burned in incinerators or boilers to recover energy. In these cases, you still have toxic emissions and residual ash contaminated with heavy metals and dioxins, though at slightly less levels than in a mass burn incinerator.
This process has not been used with municipal solid waste on other than a small pilot scale and it is likely that the costs have been underestimated, perhaps substantially. But the major problem with this process is that it would destroy vast quantities of materials that could be either recycled or composted.
Pyrolysis and Gasification
Two other technologies being promoted as clean alternatives to typical trash incinerators are pyrolysis and gasification. Pyrolysis is a thermal destruction process that burns waste in the absence of oxygen. A plasma arc is often used to generate the heat at high temperatures. This process produces a mixture of gases, liquids and solids, some of which will include toxic chemicals depending on the make-up of the original waste mixtures. With household trash, the emissions and solid residuals can be expected to include heavy metals, dioxins, and other contaminants typically found when household trash is burned.
Gasification is a similar thermal destruction process, only in this case small amounts of oxygen are present during the heating process, which also occurs at high temperatures. In this process, often called starved-air gasification, a gaseous mixture is produced that will again include toxic chemicals.
Both of these technologies are considered to be in the developmental stage with regard to their application to household trash. As a practical matter, the health and environmental concerns that these processes raise seem no different than if the waste were burned in a traditional incinerator. With both of these systems, toxic gases are formed during the treatment process that are similar to those found during the combustion of household trash in a traditional incinerator and are released out a stack. Some—but not all—of these emissions may be captured by pollution control equipment.
Co-generation Plants
Co-generation is the production of heat and electricity by the same energy plant. In a conventional power plant, coal, oil, or natural gas are burned at high temperatures to generate steam. The pressure from the steam turns a turbine that produces electricity. Only about 30 percent of the energy of the original fuel is converted to steam pressure in this process. The rest is wasted. In a co-generation plant, the excess heat is captured as low temperature steam is given off by the turbines. This steam can be used to generate heat but cannot be transmitted very far. It is used mostly for nearby factories such as pulp and paper mills that require low temperature heat for their production lines or for space heating in buildings.
The new wave of proposals include cogeneration plants that burn fuels other than coal, oil, or natural gas. Some proposals are for burning “biomass” such as wood waste, agricultural waste, peat moss and a variety of other wastes, including household garbage that has been converted into “biomass” as described above. While these plants may generate less sulfur oxides or greenhouse gases such as carbon dioxide, depending on the fuel burned, they are still incinerators that generate emissions, some of which will include toxic chemicals, depending on the make-up of fuel that is burned. With household trash, the emissions and solid residuals can be expected to include heavy metals, dioxins, and other contaminants.
Limitations of Air Pollution Controls
Most, but not all, incinerators and waste burners have air pollution control equipment that is designed to remove different pollutants generated during the combustion process. Electrostatic precipitators remove large particulates, scrubbers remove acid gases, baghouse or fabric filters remove small particles, and activated charcoal beds remove volatile gases.
None of these or any other air pollution control equipment is capable of removing 100 percent of the pollutants present in the emissions of an incinerator or waste burner. In fact, no matter what air pollution controls are used, some toxic chemicals will be released into the community. This is very important since many pollutants generated by incinerators and waste burners are carcinogenic and produce health effects even at very low levels.
Recycling vs Incineration
One of the most serious problems with these new technologies is that they compete with waste reduction, recycling, and composting programs for materials. As much as 80 percent of solid waste can either be recycled and composted, or incinerated—but not both.
Recycling not only reduces waste; it conserves energy, preserves natural resources, and reduces pollution. Raw materials processing, such as wood pulping, is extremely energy-intensive, and both the generation of energy and the production process itself produce toxic pollution. Reprocessing materials uses only a fraction of the energy needed in primary production and creates much less pollution.
Conclusion
Biomass conversion, pyrolysis, and gasification—like all incineration—are doomed technologies. These processes generate hazardous emissions and toxic ash or residue, are very expensive, compete with recycling programs, and destroy valuable resources. They will not succeed as long as an organized citizenry refuses to accept these impacts on their communities.
Trust your instincts. Take a close look at any proposed technology and ask hard questions, such as the ones provided in the box. If the vendors can’t—or won’t—provide you with written answers to these and other questions, then step back and ask yourself why. It’s usually either because they don’t have the information or because they know you won’t like the answers.
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Reprinted with permission from
Everyone’s Backyard, Center for Health, Environment and Justice
[From WS November/December 2003]