CFD modelling of meat and bone meal combustion in a cement rotary kiln – Investigation of fuel particle size and fuel feeding position impacts. (17th February 2015)

• Record Type: Journal Article
• Authors: Ariyaratne, W.K. Hiromi; Malagalage, Anjana; Melaaen, Morten C.; Tokheim, Lars-André
• Is Part Of: Chemical engineering science. Volume 123(2015)
• Page Start: 596
• Page End: 608
• Publication Date: 2015-02-17
• Subjects: CFD computational fluid dynamics -- HHV higher heating value (gross calorific value) -- MBM meat and bone meal -- RDF refuse derived fuel -- RNG Re-Normalisation Group -- WSGGM weighted-sum-of-grey-gases model; Cement rotary kiln -- Coal -- Meat and bone meal -- Combustion -- CFD -- Fuel particle size; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2014.10.048
• Languages: English
• ISSNs: 0009-2509

Abstract

Abstract: Because of high environmental impacts and energy costs, many cement plants tend to substitute waste-derived fuels for fossil fuels. However, knowing the impacts of using such waste fuels is important for improving the process economy. This paper presents a three-dimensional computational fluid dynamics (CFD) modelling study conducted for a cement rotary kiln. Simulations are performed using commercial CFD software and are conducted for coal, as well as for meat and bone meal (MBM) combustion. The effects of fuel feeding position and fuel particle size on the combustion characteristics are discussed. Annulus fuel feeding gives faster devolatilization and char combustion than central-tube fuel feeding, and the effect is significant for larger particles. The devolatilization is much faster for small particles. For a given fuel, the larger the mass-weighted mean particle diameter, the lower the char burnout. The negative effect of a large mass-weighted mean particle diameter on the char burnout is more significant for fuels having high fixed carbon content. However, the impact on the gas temperature due to poor char burnout depends on the fixed carbon content of the fuel. Highlights: 3-D CFD modelling of a full-scale cement rotary kiln burner is carried out. Coal and meat and bone meal (MBM) combustion are simulated and compared. Impacts of fuel feeding position and fuel particle size are investigated. Annulus feeding gives faster devolatilization and char burning than central tube. Larger particle size and higher fixed carbon content gives reduced char burning.