Data/hora: 14/06/2024 04:43:22

Biblioteca(s): 	Embrapa Florestas.	
Data corrente: 	19/07/2010	
Data da última atualização: 	22/03/2011	
Autoria: 	LONGUE JÚNIOR, D.; COLODETTE, J. L.; ANDRADE, M. F.	
Afiliação: 	Dalton Longue Júnior; Jorge Luiz Colodette; Marcela Freitas Andrade.	
Título: 	Alternative technique for evaluating yield loss in modern bleach plants.	
Ano de publicação: 	2009	
Fonte/Imprenta: 	Cerne, Lavras, v. 15, n. 4, p. 398-406, out./dez. 2009.	
Idioma: 	Inglês	
Conteúdo: 	In this study an alternative technique is presented and discussed for measuring yield loss based on the analysis of total
organic carbon (TOC) in bleaching filtrates. Oxygen predelignified eucalyptus kraft pulp was subjected to the DHT(EP)D, D(EP)DD
and D(EP)DP bleaching sequences and the gravimetric yield of each stage was determined, with 10 replicates. Then the filtrates were
analyzed for TOC and COD. Correlations were established among the three measurement methods (gravimetric, COD and TOC).
Yield losses in the DHT stage were more accentuated than in the D0 stage, these losses being recovered in subsequent stages of the
bleaching sequence. Yield loss decreased with each advancing stage of the bleaching sequences (D0,DHT>(EP)>D1>P>D2). Yield loss
increased with higher kappa factors in the first bleaching stage and with higher temperature in the (EP) stage. The final P stage resulted
in greater yield losses than the final D stage. Yield loss intensifies with gain in brightness from bleaching. Yield losses as measured by
the TOC method revealed a narrower range of variation in relation to the gravimetric and COD methods, and the linear equation
derived for the TOC vs. gravimetric yield relationship provided the best fit (R2=97.27%). Overall yield losses throughout were in the
range of 4-5%, depending on the bleaching sequence and operating conditions.	
Palavras-Chave: 	Bleach; COD; TOC; Yield.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Florestas (CNPF)	
Exemplares: 	CNPF - (47064-1) - ADD - AP - PP -  -  -  - DIS