Abstract
The kraft papermaking process, which is by far the predominant method used in North America, depends on recovery of the chemicals used in the digesting or pulping operation. Currently, the black liquor recovery boiler is the heart of this recovery process, but replacement of this boiler with a gasification system is being intensively studied. A switch to gasification can be justified based on capital investment, energy efficiency, and safety, but there are a number of significant obstacles to its successful development and implementation. Identification of suitable materials for the containment of the reaction and the reaction products is considered one of the most critical issues. There are currently two distinct gasification processes being actively developed; a low temperature process in which the alkali salts are kept below their melting point, and a high temperature process in which these compounds are handled in the molten state. Each process has unique materials requirements and issues that are described in this paper. In addition, results from recent studies of the compatibility of gasifier components with the respective environments are presented.
| Original language | English |
|---|---|
| Journal | NACE - International Corrosion Conference Series |
| Volume | 2003-April |
| State | Published - 2003 |
| Event | Corrosion 2003 - San Diego, United States Duration: Apr 16 2003 → Apr 20 2003 |
Funding
We are indebted to MTCI/ThermoChem, Weyerhaeuser and Chemrec for providing sample material from the various black liquor gasifiers. We want to acknowledge the contributions of metallographer H. F. Longmire who prepared the samples and conducted the optical examinations of the various samples, L. R. Walker who performed the microprobe examination of selected samples, R. W. Swindeman who participated in the analysis of the cracked tubes from the LTLP New Bern gasifier and C. M. Hoffmann who performed some of the first analyses of the refractories from the HTLP New Bern gasifier. Corhart Refractories, RHI Refractories America, Monofrax Refractories and N. V. Gouda Vuurvast generously provided refractory materials for the laboratory studies. P. F. Tortorelli and G. Sorell provided technical reviews of this manuscript, and K. A. Choudhury prepared the final manuscript. Research sponsored by the U.S. Department of Energy, Assistant Secretary for Energy Efficiency and Renewable Energy, Industrial Technologies Program, Forest Products Industries of the Future, Industrial Materials of the Future and through a Cooperative Research and Development Agreement (CRADA 97-0481) with Weyerhaeuser Company. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
Keywords
- Alkali salts
- Black liquor
- Corrosion
- Fluidized bed
- Gasification
- Hydrogen sulfide
- Materials degradation
- Slagging gasifier