Hexenuronic Acids
Mostrando 1-5 de 5 artigos, teses e dissertações.
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1. A influência dos ácidos hexenurônicos no rendimento e na branqueabilidade da polpa kraft
This study investigated the impact of pulp hexenuronic acids (HexAs) content on pulping yield by changing cooking reaction temperature. The bleachability of pulps containing variable amounts of HexAs was also investigated. The cooking at 170 ºC produced pulp of kappa number, HexAs and screen yield of 16.2, 49.4 mmol/kg and 50.2%, respectively, whereas the c
Química Nova. Publicado em: 2009
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2. The impact of kappa number composition on eucalyptus kraft pulp bleachability
Consumption of chemicals during ECF bleaching of kraft pulp correlates reasonably well with kappa number, which measures with KMnO4 the total amount of oxidizable material in the pulp. However, the method does not distinguish between the oxidizable material in residual lignin and other structures susceptible to oxidation, such as hexenuronic acids (HexAs), e
Brazilian Journal of Chemical Engineering. Publicado em: 2007-03
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3. The effects of the process conditions in the production of hexenuronic acids in cellullosic pulps / Efeito das condições de processo sobre a produção de ácidos hexenurônicos em polpas celulósicas
A indústria de papel e celulose convive com questões de adequação da oferta à demanda que influenciam na tomada de decisão em vários elos da cadeia produtiva. A pressão por baixos custos requer novos investimentos em tecnologia, normalmente associados ao processo e ao produto. Neste cenário, o objetivo do presente trabalho envolve o estudo da influ�
Publicado em: 2007
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4. Efeito dos ácidos hexenurônicos e da lignina no desempenho da ozonólize, em diferentes pHs da reação
The effect of pH on the performance of the ozonolysis stage in pulp production was evaluated for conventional and acid treated brown and oxygen delignified eucalyptus kraft pulps. The objective was to determine separately the effects of lignin and hexenuronic acid on the performance of the ozonolysis stage. The reaction of ozone with hexenuronic acid is less
Química Nova. Publicado em: 2006-10
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5. Influência da carga alcalina no processo de polpação Lo-Solids® para madeiras de eucalipto. / The influence of alkali charge on lo-solidsâ â pulping process for eucalyptus woods.
The main objective of this work was to study the influence of the alkali charge on Lo-Solidsâ modified kraft pulping process for eucalyptus, considering parameters as yield, rejects content, total dissolved solids materials and the pulp characteristics as kappa number, viscosity, carbohydrate composition and fibers dimensions. Woods from hybrids of Eucalypt
Publicado em: 2003