A Qualitative Examination of the Control of Major Gaseous Pollutants Generated in Portland Cement Kilns

摘要

In descending order of flue gas concentration, the gaseous pollutants of historical interest from cement kilns are the oxides of nitrogen, sulfur dioxide, carbon monoxide and hydrocarbons. Even though the flue gas concentrations are low, the relatively high volume of flue gas from cement kilns results in mass emissions of these gases of several tons per year. Effective pollutant abatement technologies are available and currently are applied to cement kilns in the United States. Other technologies may have potential application to cement kilns in limited circumstances. However, the individual or concurrent application of these technologies to control a specific pollutant can have unexpected effects such as the increased generation of another pollutant or an undesired outcome such as a new waste stream. In addition, the application of pollution control technologies can have synergetic or counteractive effects on the process and/or product quality. The cement manufacturing process is briefly described, and the sources of the major pollutants are presented. The potential synergetic and counteractive effects of the available and potential technologies are discussed and presented in tabular form.