Green energy at cement kiln in Cyprus—Use of sewage sludge as a conventional fuel substitute

In this paper, the results of a study concerning the utilization of sewage sludge as an alternative fuel at cement kilns, covering all process, health and safety and environmental matters, are presented. Trials have started in Vassiliko Cement Plant (Cyprus), on how to treat and utilize wet sewage sludge, of moisture content 65–70%, as an alternative fuel at the cement kilns of the plant. Environmental gaseous emission measurements, with emphasis on heavy metal concentrations, especially those of mercury (Hg), have been performed. At Vassiliko Plant, 22 000 m3 of wet sludge has been treated during the years 2003 and 2004. The new technology involves mixing of sewage sludge with pet coke and then incinerating the mixture at high temperatures. Since cement plants burn fuel at 1400 °C, the new sewage sludge-based fuel does not emit dioxin harmful to human health.