Below are the answers to some frequently asked questions about energy recovery from hazardous waste in cement kilns.

What is Fuel-Quality Waste?

• Cement is the most widely used construction material in the world. Cement is produced in huge rotary kilns by heating a mixture of minerals to over 2600 degrees F. This is a very energy intensive process and cement manufacturers have developed technology that allows the use of waste created by other industrial processes to replace non-renewable fossil fuels. These waste fuels include: used paint solvents, discarded paints and coatings, inks and ink solvents, various resins and organic sludges, petroleum refining chemical manufacturing by-products, etc. All of these items are examples of the types of waste that can be used in the cement industry's energy recovery programs.

Why Are These Fuel Sources Called "Hazardous Waste"?

• It is important to remember that many of these types of waste are labeled "hazardous" mainly because they are flammable. Others receive this designation because improper handling and disposal could adversely affect the environment. The important point is that the regulated waste used by cement kilns and identified as "hazardous" cannot legitimately be land-disposed without prior treatment. For the vast majority of these types of wastes, EPA has designated thermal treatment such as energy recovery in cement kilns as the Best Demonstrated Available Technology (BDAT) for treating them safely.

Is Energy Recovery Safe?

• Energy recovery from hazardous waste is a safe process. Each step of the recycling process is highly regulated and subject to strict safety standards. The regulations govern both air emissions and waste management practices (transportation, handling, and storage.) Cement kilns that use hazardous waste as fuel are strictly regulated by the Resource Conservation and Recovery Act (RCRA), the Community Right-to-Know Act (EPCRA), and the Clean Air Act (CAA).

What are the Benefits of Energy Recovery?

• The benefits of energy recovery are significant. When cement kilns use fuel-quality waste, hazardous waste is removed from the environment and is handled and used in a safe and responsible manner. In addition, the amount of fossil fuel needed to produce cement is reduced, thereby conserving non-renewable energy resources.

Does Using Fuel-Quality Waste Affect the Cement?

• No. The use of fuel-quality waste as fuel in cement kilns has no effect on the quality of the cement. In fact, EPA considered the question of cement product quality in 1995 and concluded that "It is not substantiated that burning WDF increases risks posed to end users of cement"