Meat and Bone Meal as a Renewable Energy Source in Cement Kilns: Investigation of Optimum Feeding Rate
DOI:
https://doi.org/10.24084/repqj09.609Abstract
Meat and Bone Meal (MBM) is a CO2 neutral fuel, and hence is a good candidate for substituing fossil fuels like pulverized coal in rotary kiln burners used in cement kiln systems. MBM is used in several cement plants, but the optimum substitution rate has apparently not yet been fully investigated. The present study aims to find the maximum possible replacement of coal by MBM, without negatively affecting the product quality, emissions and overall operation of the process. A full-scale experiment was carried out in the rotary kiln burner of a cement plant by varying the MBM substitution rate from 0 to 7 t/hr. Clinker quality, emissions and other relevant operational data from the experiment were analysed. Additionally, coal and MBM were compared by laboratory experiments. The results revealed that MBM could safely replace more than 40% of the coal energy without giving negative effects. The limiting factor is the free lime content of the clinker. Possible explanations to the free lime increase are given. If 40% of the coal in the rotary kiln burner was replaced by MBM on a long-term basis, the total annual CO2 emissions of the plant could be reduced by 10%.