Q: What happens inside a modern waste-to-energy facility?
A: The energy value of municipal solid waste (MSW) can be recovered through waste-to-energy incineration. Modern energy recovery facilities burn MSW in special combustion chambers, then use the resulting heat energy to generate steam or electricity. This process reduces the volume of MSW to be landfilled by as much as 90 percent.
Energy recovery facilities are designed to achieve high combustion temperatures, which help MSW burn cleaner and create less ash for disposal. Modern air pollution control devices - electrostatic precipitators, dry and wet scrubbers, and/or fabric filters - are used to remove potentially harmful particulates and gases from incinerator emissions.
Q: Is waste-to-energy incineration safe?
A: Yes. In 1989, the U.S. Conference of Mayors convened an international blue-ribbon panel of experts to discuss the health and safety impacts of waste-to-energy incineration. The symposium participants concluded that a properly equipped, operated and maintained energy recovery facility can operate within existing regulatory standards for human health and safety. The Clean Air Act of 1991 provided for an additional margin of security with tightened emissions standards. Furthermore, many communities are recognizing the importance of removing recyclables, as well as items such as batteries and household hazardous wastes, before incineration to reduce toxic components in incinerator ash.
The symposium participants found that, contrary to popular misconception, there is no evidence to link the incineration of PVC with increased dioxin emissions. Similar conclusions have been reached in a number of sources, including a 1987 study for the New York State Energy Research and Development Authority. Generally speaking, electricity is generated as safely through waste-to-energy incineration as it is through a power plant.
Q: How much waste-to-energy capacity is there?
A: There are 121 energy recovery facilities operating in the United States, with a designed capacity of nearly 97,000 tons per day. An additional five facilities are under construction and 31 are in the planning stages. If all of these facilities come on line as planned, 19 percent of the nation's MSW will be processed by energy recovery facilities by the year 2000.
Q: How do plastics contribute to waste-to-energy incineration?
A: Plastics are derived from petroleum or natural gas, giving them a stored energy value higher than any other material commonly found in the waste stream. In fact, one pound of plastics can generate twice as much energy as Wyoming coal and almost as much energy as fuel oil. When plastics are processed in modern waste-to-energy facilities, they can help other waste combust more completely, leaving less ash for disposal in landfills.
Energy Values
Material Btu/pound
Plastics
PET 10,900
HDPE 18,700
Other Plastic Containers 16,400
Other Plastics 17,900
Rubber & Leather 12,800
Newspaper 8,000
Corrugated Boxes (paper) 7,000
Textiles 9,400
Wood 7,300
Average for MSW 5,900
Yard Wastes 2,900
Food Wastes 2,900
Heat Content of Common Fuels
Fuel Oil 20,900
Wyoming Coal 9,600
Courtesy: SPI
Showing posts with label Facts about Plastics; Plastics Myth and facts. Show all posts
Showing posts with label Facts about Plastics; Plastics Myth and facts. Show all posts
Sunday, September 12, 2010
Plastics and Energy Efficiency !!
Q: Can plastics actually save energy?
A: Yes. And they use less energy than you might think: the raw materials that go into the production of plastics account for only 1.5 percent of total energy consumption. In addition, it often takes less energy to convert plastics from a raw material into a finished product than comparable products made of other materials:
• Plastic grocery bags require 40 percent less energy to make than paper bags.
• Foam polystyrene containers require 30 percent less total energy than paperboard containers.
• Fifty-three billion kilowatt hours of electricity are saved annually by improvement in major appliance energy efficiency made possible by plastic applications. Without plastics, these appliances would use 30 percent more energy.
Q: Would more energy be conserved if plastic packaging were replaced by non-plastic alternatives?
A: No. In fact, the total energy used in manufacturing plastic packaging is considerably less than the energy used to produce non-plastic alternatives -- even when the inherent energy value of plastics' raw materials is factored in. This means that without plastics, the equivalent of an additional 58 million barrels of oil or 325 billion cubic feet of natural gas would have been required to meet America's packaging needs in 1990. That's enough to meet the energy needs of 100,000 homes for 35 years.
A: Yes. And they use less energy than you might think: the raw materials that go into the production of plastics account for only 1.5 percent of total energy consumption. In addition, it often takes less energy to convert plastics from a raw material into a finished product than comparable products made of other materials:
• Plastic grocery bags require 40 percent less energy to make than paper bags.
• Foam polystyrene containers require 30 percent less total energy than paperboard containers.
• Fifty-three billion kilowatt hours of electricity are saved annually by improvement in major appliance energy efficiency made possible by plastic applications. Without plastics, these appliances would use 30 percent more energy.
Q: Would more energy be conserved if plastic packaging were replaced by non-plastic alternatives?
A: No. In fact, the total energy used in manufacturing plastic packaging is considerably less than the energy used to produce non-plastic alternatives -- even when the inherent energy value of plastics' raw materials is factored in. This means that without plastics, the equivalent of an additional 58 million barrels of oil or 325 billion cubic feet of natural gas would have been required to meet America's packaging needs in 1990. That's enough to meet the energy needs of 100,000 homes for 35 years.
Facts about Plastics
Q: How are plastics made?
A: Plastics consist of building blocks called hydrocarbons, typically derived from petroleum or natural gas. These monomers (small molecules) are bonded into chains called polymers or plastic resins. Different combinations of monomers yield resins with special properties and characteristics.
Q: Why are plastics used in packaging?
A: Packaging serves many purposes, but one of its primary functions is to help protect the quality of goods - ranging from sensitive electronics to fresh and prepared foods - during shipping, handling and merchandising. Plastics are a versatile family of materials that are suitable for a wide range of packaging applications. In many cases, plastics offer the best protection while using minimal resources and creating less waste than alternative materials. In fact, 400 percent more material by weight would be needed to make packaging if there were no plastics, while the volume of packaging would more than double.
Q: Why are plastics used in durable goods?
A: Manufactured items with a useful life of more than three years - cars, appliances, computers, etc. - are called durable goods. Manufacturers of durable goods choose plastics for the following reasons:
1. The automotive industry chooses plastic for its durability, corrosion resistance, ease of coloring and finishing, resiliency, energy efficiency and light weight. Light weight, for instance, translates into lowered handling and transportation costs all down the line. Where a plastic film (as in stretch wrap) can replace a heavy shipping crate or carton, the weight savings can be an order of magnitude or more.
2. Major appliance manufacturers use plastics because of their ease of fabrication and outstanding thermal insulation characteristics, that significantly reduce energy consumption.
3. The building and construction industry uses vinyl siding for homes because of its appearance, durability, ease of installation and energy efficiency. Plastics can reduce energy consumption for the auto, appliance, and building and construction industries, providing a substantial savings in production costs.
Q: Why do we need different kinds of plastics?
A: Copper, silver and aluminum are all metals, yet each has unique properties. You wouldn't make a car out of silver or a beer can out of copper because the properties of these metals are not chemically or physically able to create the most effective final product. Likewise, while plastics are all related, each resin has attributes that make it best suited to a particular application. Plastics make this possible because as a material family they are so versatile.
Six resins account for nearly all of the plastics used in packaging:
• PET (polyethylene terephthalate) is a clear, tough polymer with exceptional gas and moisture barrier properties. PET's ability to contain carbon dioxide (carbonation) makes it ideal for use in soft drink bottles.
• HDPE (high density polyethylene) is used in milk, juice and water containers in order to take advantage of its excellent protective barrier properties. Its chemical resistance properties also make it well suited for items such as containers for household chemicals and detergents.
• Vinyl (polyvinyl chloride, or PVC) provides excellent clarity, puncture-resistance and cling. As a film, vinyl can breathe just the right amount, making it ideal for packaging fresh meats that require oxygen to ensure a bright red surface while maintaining an acceptable shelf life.
• LDPE (low density polyethylene) offers clarity and flexibility. It is used to make bottles that require flexibility. To take advantage of its strength and toughness in film form, it is used to produce grocery bags and garbage bags, shrink and stretch film, and coating for milk cartons.
• PP (polypropylene) has high tensile strength, making it ideal for use in caps and lids that have to hold tightly to threaded openings. Because of its high melting point, polypropylene can be hot-filled with products designed to cool in bottles, including ketchup and syrup. It is also used for products that need to be incubated, such as yogurt.
• PS (polystyrene), in its crystalline form, is a colorless plastic that can be clear and hard. It can also be foamed to provide exceptional insulation properties. Foamed or expanded polystyrene (EPS) is used for products such as meat trays, egg cartons and coffee cups. It is also used for packaging and protecting appliances, electronics and other sensitive products.
Q: What about CFCs (Cloro Floro Carbon)?
A: Most (nearly 70 percent) of polystyrene foam products never were made with chlorofluorocarbons (CFCs). In the late 1980s, those few polystyrene manufacturers that used them announced the voluntary phaseout of CFCs.
Courtesy: SPI
A: Plastics consist of building blocks called hydrocarbons, typically derived from petroleum or natural gas. These monomers (small molecules) are bonded into chains called polymers or plastic resins. Different combinations of monomers yield resins with special properties and characteristics.
Q: Why are plastics used in packaging?
A: Packaging serves many purposes, but one of its primary functions is to help protect the quality of goods - ranging from sensitive electronics to fresh and prepared foods - during shipping, handling and merchandising. Plastics are a versatile family of materials that are suitable for a wide range of packaging applications. In many cases, plastics offer the best protection while using minimal resources and creating less waste than alternative materials. In fact, 400 percent more material by weight would be needed to make packaging if there were no plastics, while the volume of packaging would more than double.
Q: Why are plastics used in durable goods?
A: Manufactured items with a useful life of more than three years - cars, appliances, computers, etc. - are called durable goods. Manufacturers of durable goods choose plastics for the following reasons:
1. The automotive industry chooses plastic for its durability, corrosion resistance, ease of coloring and finishing, resiliency, energy efficiency and light weight. Light weight, for instance, translates into lowered handling and transportation costs all down the line. Where a plastic film (as in stretch wrap) can replace a heavy shipping crate or carton, the weight savings can be an order of magnitude or more.
2. Major appliance manufacturers use plastics because of their ease of fabrication and outstanding thermal insulation characteristics, that significantly reduce energy consumption.
3. The building and construction industry uses vinyl siding for homes because of its appearance, durability, ease of installation and energy efficiency. Plastics can reduce energy consumption for the auto, appliance, and building and construction industries, providing a substantial savings in production costs.
Q: Why do we need different kinds of plastics?
A: Copper, silver and aluminum are all metals, yet each has unique properties. You wouldn't make a car out of silver or a beer can out of copper because the properties of these metals are not chemically or physically able to create the most effective final product. Likewise, while plastics are all related, each resin has attributes that make it best suited to a particular application. Plastics make this possible because as a material family they are so versatile.
Six resins account for nearly all of the plastics used in packaging:
• PET (polyethylene terephthalate) is a clear, tough polymer with exceptional gas and moisture barrier properties. PET's ability to contain carbon dioxide (carbonation) makes it ideal for use in soft drink bottles.
• HDPE (high density polyethylene) is used in milk, juice and water containers in order to take advantage of its excellent protective barrier properties. Its chemical resistance properties also make it well suited for items such as containers for household chemicals and detergents.
• Vinyl (polyvinyl chloride, or PVC) provides excellent clarity, puncture-resistance and cling. As a film, vinyl can breathe just the right amount, making it ideal for packaging fresh meats that require oxygen to ensure a bright red surface while maintaining an acceptable shelf life.
• LDPE (low density polyethylene) offers clarity and flexibility. It is used to make bottles that require flexibility. To take advantage of its strength and toughness in film form, it is used to produce grocery bags and garbage bags, shrink and stretch film, and coating for milk cartons.
• PP (polypropylene) has high tensile strength, making it ideal for use in caps and lids that have to hold tightly to threaded openings. Because of its high melting point, polypropylene can be hot-filled with products designed to cool in bottles, including ketchup and syrup. It is also used for products that need to be incubated, such as yogurt.
• PS (polystyrene), in its crystalline form, is a colorless plastic that can be clear and hard. It can also be foamed to provide exceptional insulation properties. Foamed or expanded polystyrene (EPS) is used for products such as meat trays, egg cartons and coffee cups. It is also used for packaging and protecting appliances, electronics and other sensitive products.
Q: What about CFCs (Cloro Floro Carbon)?
A: Most (nearly 70 percent) of polystyrene foam products never were made with chlorofluorocarbons (CFCs). In the late 1980s, those few polystyrene manufacturers that used them announced the voluntary phaseout of CFCs.
Courtesy: SPI
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