Co-firing of refuse-derived fuel (RDF) with natural gas in a cement kiln: Summary of test results

In July of 1986, the Environmental Equipment Corporation, in association with the Portland Cement Association and the Gulf Coast Portland Cement Company, initiated a program to develop and test refuse-derived fuel (RDF) on a commercial scale as a supplemental energy source for the portland cement industry. The objectives of the work performed were to definitely determine the technical and operational limits on the use of RDF, and to develop and test the equipment and systems required by cement plants to use RDF on a full-time commercial basis. Three extended trial burns were completed with satisfactory results at the Gulf Coast Portland Cement Company's plant in Houston, Texas. Prior to these tests, the kiln was normally fired with natural gas to produce clinker by the wet process. During the trial burns, 20%, 30%, and 40%, respectively, of the heat input was supplied by RDF. Each test lasted approximately three days, in all producing 8500 tons of cement while burning 1338 tons of RDF. Analyses of the cement clinker, kiln feed, flue dust, ash, precipitator dust, and cooler dust by an independent testing authority -- the Portland Cement Association -- showed acceptable clinker quality and acceptable environmental data. Although some loss ofmore » cement product strength was encountered in the third (i.e., 40% RDF) test, this may have been due to an inadvertent, temporary loss of temperature control.« less