M.S. Thesis: Application of Thermal Spray Techniques for Combating High Temperature Corrosion of WTE Superheater Tubes

By Dianyi Yan

Advisor: Professor Nickolas J. Themelis
Co-advisor: A.C. (Thanos) Bourtsalas

Department of Earth and Environmental Engineering
Fu Foundation School of Engineering & Applied Science
Columbia University

May 7, 2017

Combustion with energy recovery of post-recycling municipal solid waste (MSW), also called waste to energy (WTE), is the only proven alternative to landfilling. Some of the WTE advantages over landfilling are that it avoids landfilling and methane emissions to atmosphere and reduces the volume of MSW by 90%. One of the main operational problems in the WTE industry is the corrosion on the superheater tubes, which is related to the relatively high concentration of chlorine (0.47-0.72 wt%) in the flue gas and the formation of alkaline salts and sulfates. Corrosion affects adversely the operation of WTE plants due to the cost and time needed to repair or replace the superheater tubes. Several coating techniques have been applied for preventing high temperature corrosion (HTC) inside the WTE boilers. The most common techniques are weld overlays, laser claddings, fused coatings and thermal spray coatings.

Download Thesis (pdf)