Recycling of bleaching effluents into the black liquor recovery system has become an important step of a closed cycle technology that, in a kraft pulp mill, will result in a reduction in pollutants discharge into receiving waters and also a decrease of fresh water consumption. / In the current work, the combustion of pre-dried solid samples of black liquor (BL), chlorination effluent (C/D), and extraction effluent (E 1) as well as two-component and three-component mixtures was investigated experimentally in a Thermogravimetric Analyzer (TGA) and in a Constant-Temperature Tube Furnace. / Results of the thermogravimetric analyses showed that solids from the C/D stage were similar to those of the black liquor solids in the volatile matter, char, and ash contents, while the solids from the E1 stage contained less volatiles and were richer in their ash content. Results also revealed that both effluents were devolatilized and gasified at lower rates than that of black liquor. The addition of up to 20% of either effluent did not have a significant impact of the TGA behaviour of black liquor. In addition, mixtures containing solids from the three liquors were very close to black liquor in terms of their devolatilization and gasification rates and followed a weight-loss trend similar to that of black liquor. / Effect of temperature, O2, mixing ratio on the chemical compositions of combustion products was investigated in a constant-temperature tube furnace. Chemical analyses of the gaseous and solid phases were performed using a Mass Spectrometer (MS) and an Ion Chromatograph (IC), respectively. Results showed the combustion products of two-component mixtures containing up to 20% of C/D or E1 in black liquor solids would not be significantly different from those of typical black liquor, except that they contained more HCl in the gas phase and larger amounts of chloride in the solid phase, especially when C/D was added. Their amounts were greatly influenced by temperature and oxygen. Combustion of three-component mixtures (BL-C/D-E1) resulted in products very similar to those obtained during the combustion of black liquor alone. The HCl yield was increased with temperature and BL content in the mixture.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.84459 |
| Date | January 2003 |
| Creators | Al-Wohoush, Mohammad |
| Contributors | Kubes, G. (advisor), Berk, D. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002150804, proquestno: AAINQ98192, Theses scanned by UMI/ProQuest. |
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