Learn more about CCP use in Texas
Coal Combustion Products: Recycling in Texas
What Are Coal Combustion Products?
Coal Combustion Products (CCPs) are the materials remaining from burning coal at electric power plants. CCPs include three primary materials: Fly Ash, Bottom Ash, and Flue Gas Desulphurization Material (FGD). Fly Ash is the fine particle residue removed from stack gases with various types of air pollution control equipment. Bottom Ash is the coarse, unburned solid matter that falls to the bottom of the boiler. FGD Material is the solid material produced in the air pollution control processes when stack gasses pass through pulverized limestone to remove sulfur dioxide.
How Much CCPs Are Generated In Texas?
Texas power plants produce over 13 million tons of CCPs each year. If this material was all loaded into dump trucks, the line of trucks would stretch from Austin to Boston and back. This is the state’s second largest potential waste stream, behind municipal solid waste, which amounts to over 18 million tons per year.
Why Recycle CCPs?
CCPs have characteristics similar to virgin materials such as cement, lime, clay, sand, gypsum, and aggregates. As a result, CCPs can be used to make numerous construction products, from concrete blocks to synthetic gypsum. Unfortunately, most CCPs are currently being disposed. CCPs are not only abundant, they are non-hazardous and are not considered to be a waste material when used in beneficial applications.
Fly ash is a material with a chemical composition similar to Portland cement and can replace a portion of the cement in concrete. Concrete containing Fly Ash is used widely in housing, office buildings, bridges, roads and highways, building blocks and concrete pipe. Bottom Ash is used as a substitute for sand, gravel, or limestone aggregates for a number of construction and building products, including concrete block, clay brick, and asphaltic concrete. FGD Material can be used to make a synthetic gypsum that is used in the production of wallboard for the building industry, in agricultural applications, and as a setting agent in the manufacture of cement. The material can also be used to make a road base to replace such products as sand and gravel.
What Benefits Accrue From Recycling CCPs?
Recycling CCPs into useful products can save utility customers millions of dollars a year. Unless they are recycled, the CCPs must be land filled, and the associated disposal expenses are passed along to the ratepayers. Recycling also saves energy because CCPs replace products that require considerable energy to manufacture. Each ton of Fly Ash that replaces a ton of cement saves the equivalent of nearly one barrel of imported oil. Substituting CCPs for such products as limestone, clay, sand, and gravel also reduces depletion of these valuable resources.
What Are The Environmental Benefits?
Recycling CCPs results in reduced dedication of otherwise productive land to landfill usage. Recycling Fly Ash also means reduced emissions of air pollutants which result from making competing products such as lime and cement. Each ton of Fly Ash used to replace cement saves one tone of carbon dioxide (greenhouse gas) emissions. It also means fewer environmental problems, such as surface and groundwater problems, associated with mining virgin materials and reclaiming the land.
Environmental Benefits of Recycling
Coal Combustion Products
In addition to providing good engineering and physical qualities, as well as economic benefit, recycling of Coal Combustion Products (CCPs) provides many environmental benefits. CCPs result from the generation of electricity by burning coal as fuel in power plants. The production of coal ash can only be avoided by the conversion of these major sources of clean electrical energy to more expensive alternate fuels. Society should benefit from these Products of power generation (which will be produced whether they are recycled or not) by using these high quality, readily available, and abundant products in lieu of mining additional virgin materials. Increased usage of CCPs, whose production amounts to over 13 million tons in Texas each year, would protect valuable natural resources while decreasing the stress on the environment.
- Energy can be saved by reducing fossil fuel consumption required to produce competing products such as cement, lime, and crushed stone, and to mine products such as gypsum, limestone, sand, clay, and gravel. For example, each ton of Fly Ash used to replace a ton of cement saves the equivalent of one barrel of oil required to produce the cement. Cement and lime are the third most energy-intensive materials to produce on a per ton basis, next to steel and aluminum.
- CCP recycling reduces Greenhouse Gas emissions from the manufacture of cement and lime. For each ton of Fly Ash that is recycled to replace cement and lime, one ton of Carbon Dioxide gas (the primary Greenhouse Gas) is saved by reducing the need to produce cement and lime.
- We can reduce the dedication of thousands of additional acres of productive land to a very poor use for constructing landfills which will be required if the CCPs are disposed. The utilities and their rate payers will also benefit from reduced costs when additional land and facilities are not developed for these landfills or ponds. These benefits include the reduced energy requirements and operating costs of trucking, water, fuel, heavy equipment, and mined clay for liners and soil for covers, that are required to dispose of non-recycled CCPs.
- The depletion of valuable natural resources such as limestone, gypsum, aggregates, topsoil, clay, and sand as well as the visual scars that their mining places on the land, can be reduced. We can also reduce the reclamation of abandoned quarry and strip mine sites that were used to produce competing products.
- Industrial pollution can be prevented by reducing emissions associated with industries which produce the power, fuel, and equipment required to operate the facilities which manufacture or mine competitive products.
- We can save energy by using local CCP sources instead of using more distant aggregate and gypsum supplies.
These environmental benefits can be realized only because CCP materials are environmentally safe. They contain traces of heavy metals and radioactive substances, but these same trace levels are also typically present in the natural rocks, soils, and other natural products. CCPs are no more harmful than the products they compete against. The U. S. Environmental Protection Agency treats them as non-hazardous wastes because of their “limited risk”, and indeed, promotes their recycling in all federal procurement and construction programs.