Dynamic Model of a Slagging Entrained-Flow Gasifier Including Models of Slag Transport, Deposition, and Slag Layer

• Published in: Industrial & engineering chemistry research 2016-01, Vol.55 (1), p.279-292
• Main Authors: Pednekar, Pratik, Bhattacharyya, Debangsu, Kasule, Job S, Turton, Richard, Rengaswamy, Raghunathan
• Format: Article
• Language: English
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.5b03317

Molten slag flows along the wall of slagging entrained-flow gasifiers. A lower operating temperature of these gasifiers can result in slag buildup that may eventually lead to shut down. Thus, the thickness of the slag layer is an important operating variable. However, it is difficult to monitor the thickness of the slag layer due to the extremely harsh environment inside these gasifiers. To investigate the impact of various operating conditions on the slag layer thickness, a dynamic model has been developed by including models of slag deposition, transport, and a flowing slag layer in a previously developed hybrid shrinking-core, shrinking-particle model of a gasifier. The enhanced model is used to study the effect of particle size distribution, switch in coal type, change in ash composition, and various operating conditions on the slag layer thickness. The model is used to identify important variables that significantly affect the slag layer thickness. The study shows that optimal operating conditions should be decided by evaluating the risk of slag solidification at lower temperature and accelerated degradation of the refractory at higher temperature while maintaining the desired extent of carbon conversion for the given type of coal.