François Nicol

Fireside Corrosion in Energy Recovery Boilers and Maintenance Issues

Fireside corrosion is since a long time the main limitation to increase efficiency of energy recovery boilers of waste to energy (W-t-E) facilities. Nevertheless, the increase of steam conditions in addition with the variation of feeding fuels composition imply greater risks of fouling and corrosion along with heat exchanger failure, loss of plant availability and high maintenance costs. Fireside corrosion mechanisms had already been widely treated in the literature and this paper will review the main critical factors that enhance fireside corrosion of superheater. Recent failure cases will be developed in regards with recent studies that provide interesting routes to predict corrosion failure and develop maintenance strategy.

USING OF AN EXPERIMENTAL DESIGN TO CHARACTERIZE THE CONVECTIVE DRYING BEHAVIOR OF DIFFERENT SLUDGES

Drying appears as a major step prior to valorization of sludge from a wastewater treatment plant. This study uses an experimental design on different sludges to highlight the drying behavior according to drying conditions, storage, and extrusion. This research is performed with an industrial view, but on a single cylinder sample, and focuses on five factors: maximum drying flux, time to reach 95% of dry matter, final volume, critical moisture, and slowing-down coefficient.

Superheater Fireside Corrosion Mechanisms of SA192 and AISI 316L in WtE Environment: Lab-Scale and Industrial Results

Increase of the energy recovery efficiency facilities is one of the challenges fixed recently by UE to Municipal Solid Waste Incineration (MSWI) operators. To achieve this target, one option consists in optimizing the water/steam cycle to increase electrical efficiency. Nevertheless, higher steam temperature into heat exchanger tube is expected to increase the risks of fireside corrosion, particularly on superheater tubes, along with important loss of materials, frequent shutdowns for repairs and high operational costs. In this study, fireside corrosion test had been performed using an innovative laboratory-scale corrosion pilot. Effect of increase in metal temperature from 400°C to 450°C on corrosion performances of SA192 carbon steel tube and AISI 316L stainless steel had been examined. Mechanisms and corrosion rates are discussed with regards to lifetime reported for both materials after 1 year in service in the same plant.