Q: I am an owner/operator of a crematory and am very conscious of the environment and want to be as "green" as I can with regard to my crematory operation. What are some things I can do that will ensure the cleanest possible emissions and least possible impact on the environment?
A: Environmental conscientiousness, global warning and individual planetary responsibility are becoming increasingly important to many people. With regard to cremation, knowing which pollutants are emitted from your cremator is important, as is knowing how your equipment reduces these pollutants and the methods available to reduce them further.
One of the best methods of reducing pollutant output is also one of the easiest: scrutinizing the remains, container and anything else included for cremation. Non-chlorinated plastics should be requested whenever possible so the amount of hydrogen chloride produced from the cremation can be minimized. It is important to cremate the heaviest bodies first and to request from your funeral home clients that no unnecessary items be included in the container for cremation. These practices minimize the chance of cremating at a rate of combustion that exceeds the capacity of the equipment, which can lead to visible emissions and pollution exiting the stack.
Retention time -- the length of time gases produced from the cremation are held in the cremator's secondary chamber before being exhausted to the atmosphere -- is another important consideration. Adequate retention time is necessary for the secondary chamber to further combust the products of combustion produced in the main chamber. In many older installations, the retention time in the secondary chamber is insufficient to meet current standards. Increasing the afterchamber's volume increases the likelihood that the exhaust gases will be sufficiently exposed to the temperatures required, thereby reducing the amounts of pollutants exhausted to the atmosphere.
Adequate and steady temperature levels are vitally important to maintaining the quality of exhaust gases. Typically, the desired range of operating temperatures in the secondary chamber is from 1400 to 1800 degrees Fahrenheit, depending on local environmental requirements. In cremation, temperatures higher than 1800 degrees are not necessarily better for pollution control and can, in fact, create more pollution. When temperature in the cremation equipment exceeds the designed level, the body burns faster and the exhaust gases expand to a greater volume. This overloads the secondary chamber, which then cannot destroy the pollutants as quickly as they are being produced. Temperatures that are too low result in under-combusted gases and higher emissions.
Turbulence is also important in reducing pollutants.Turbulence is created in most modern crematory equipment's exhaust flow by physical obstacles such as baffles and perforated walls, which cause the exhaust gases to twist, turn, change directions and squeeze their way through the passages in the secondary chamber. This forces the exhaust gases to mix thoroughly with the oxygen introduced into the system, while exposing them to the temperatures maintained in the secondary chamber.