Abstract
In this work, the effects of hot water pre-extraction of depithed bagasse on the soda pulping and surface properties were studied. The conditions of hot water pre-extraction were: maximum temperature 170°C, heat-up time 90min, time at maximum temperature 10min, and solid to liquor ratio (S:L) 1:8. Consequently, the pre-extracted and un-extracted bagasse chips were subjected to soda pulping at 160°C for 1h with 11, 14 and 17% active alkali charge and an S:L of 1:5. The results showed that the hot water pre-extraction increased bagasse surface texture porosity by hemicellulose degradation. Therefore, the delignification was faster for pulping of pre-extracted samples. At a certain charge of alkali, pre-extracted samples showed higher screened yield and lower Kappa number. For instance, at 17% alkali charge, pre-extracted bagasse gave 11.3% higher pulp yield compared with the un-extracted ones. Inverse gas chromatography (IGC) results showed that the hot water pre-extraction changed the active sites on the bagasse surface, decreasing the dispersive energy and the basicity character, and affected the particle morphology. The pulping process decreased the hydrophobicity and the basicity of the bagasse surface. The surfaces of un-extracted and pre-extracted bagasse pulps had similar properties but different morphology. The pulps present higher surface area and permeability with more reactive capacity.
Highlights
In recent years, interest in the isolation of hemicelluloses from woody biomass has greatly increased [1,2,3,4,5]
They observed that a change in hemicellulose content from 20 to 15% decreased the total charge of the fibers but did not affect the zeta potential, whereas the
Bagasse chips were contacted with water in an electrically heated oil bath containing 4 bombs of 2.5 L capacity
Summary
Interest in the isolation of hemicelluloses from woody biomass has greatly increased [1,2,3,4,5]. Several researchers have studied the different types of hemicellulose extractions, such as hot water extraction (autohydrolysis), and alkaline and acidic extraction on several wood and non-wood species [5,6,7,8,9,10]. Some of these studies have focused on the impact of extractions on the pulp properties prepared from pre-extracted wood [3,4,10,11]. They observed that a change in hemicellulose content (achieved by modified pulping) from 20 to 15% decreased the total charge of the fibers (cationic demand) but did not affect the zeta potential, whereas the
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