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| Author(s): |
Francides Gomes da Silva Júnior
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 1994-09-13 |
| Advisor: | Luiz Ernesto George Barrichelo |
| Abstract | |
In this research was investigated the possibility of convert the kraft pulping process of Eucalyptus grandis in soda process by the addition of disodium salt of 1,4-dihydro-9,10-dihydroxianthracene (DDA). Besides the reduction/elimination of sulfidity, was looked for the reduction of the alkalinity charge and energy consumption without prejudice the process characteristics and pulp quality. In the stage of determination the best level of DDA was concluded that 0,04% of DDA was the level that showed the best results for the process characteristics and also for the pulp; with this level was possible to reduce alkaline charge from 14 to 13% (approximately 7%). After have fixed the levels of DDA and active alkaly, was reached a reduction in the H factor near to 20% without prejudice the pulp quality and process characteristics. On the last stage of this research was evaluated the effect of sulfidity on Eucalyptus grandis cookings with 0,04% of DDA, active alkaly of 13% and H factor of 522. On this stage was observed that sulfidity have a beneficial effect, specially for the pulp viscosity; however, ideal sulfidity level was between 5 and 10%. DDA shows good effects in soda and kraft pulping process of Eucalyptus grandis allowing the reduction of chemical charge (specially sulfidity) and energy consumption during cooking without damage the pulp quality or process characteristics. The sulfidity reduction represents a great advance in the reduction of the environmental impacts caused by kraft pulp mills. (AU) | |