Steam reforming/gasification of the black liquor produced during pulping of wood or other biomass materials offers the potential for more efficient recovery of energy, reduction of emissions and improved safety. This technology is currently being used in two North American paper mills operating on the semi-chem process. As might be expected in scaling up any new process system, a number of problems have been encountered. Degradation of both metallic and refractory components has been observed in several areas, and this paper presents the results of the examinations of a number of these damaged components. Carburization of the metallic tubular components of pulse heaters has been observed and is an unexpected phenomenon. Significant oxidation occurred, but the surface oxides formed appeared not to protect against carbon penetration. Laboratory corrosion studies in an environment that simulates the conditions in the reformer/gasifiers provide some guidance on the selection of alternate materials.
Keywords: steam reforming, gasification, black liquor, carburization, oxidation, sensitization