Preparation of cellulose from oil palm empty fruit bunches via ethanol digestion : Effect of acid and alkali catalysts.
Ethanol digestion of Gil palm empty fruit bunches (OPEFB) fibres at a temperature between 165 GC - 180 GC far 2 hr and at a solid-to-liquid ratio ofl 10:1, ethanol-to-water ratio of l:l, and with or without 10 per cent 1 N HCl and 1.25 M NaOH as catalysts was studied in order to prepare cellulose via ethanol pulping. The pulp produced was studied for yield, moisture content, solubility in cold/hot water and 1 per cent NaOH, lignin, halocellulose and a-cellulose content. The highest yield of pulp (57 per cent, oven dried weight basis) was from OPEFB fibres digested at 170 GC for 2 hr without addition of catalyst, whereas OPEFB fibres digested at 175 GC for 2 hr with acid catalyst gave the lowest yield of 45 per cent (oven dried weight basis) pulp. Higher cooking temperature gave lower yield of pulp since the reaction hydrolyzed out the hemicellulose, lignin and part of the cellulose. The reactions at 165 GC, 170 GC and 175 GC with acid catalyst produced 56 per cent, 50 per cent and 45 per cent of pulp yield, respectively. It was fauna that a temperature of 180 GC with or without catalyst was too high for pulping because it totally digested the fibre into a viscous soluble pulp. On the effect of catalysts, acid catalyst was fauna to enhance the pulping of OPEFB fibres. Without the acid catalyst, at temperature of 165 GC, the fibres could not be fully cooked and would still be in the fibrous form. Reactions at 170 GC and 175 GC without catalyst gave 57 and 55 per cent yield of pulp, respectively whereas with acid catalyst gave 50 and 45 per cent yield of pulp respectively. The base catalyst could only fully pulp the OPEFB fibres at a temperature of175 GC, but the fibres dissolved at temperature 180 GC. Pulp produced at 175 GC for 2 hr with 10 per cent 1.25 M NaOH gave the best quality pulp, which contained lowest lignin and highest holocellulose at 8.2 and 91.8 per cent (based on the dry weight of pulp), respectively. The maximum yield of a-cellulose (isolated from the pulp) also was obtained from OPEFB digested with alkali catalyst at 175 GC for 2 hr (64.3 per cent based from dry weight of pulp; 34.1 per cent based on dry weight of OPEFB).
| Main Authors: | , , |
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| Format: | Texto biblioteca |
| Language: | d |
| Subjects: | Alcohol, Celulosa., Etánol., Raquis, Rendimiento., Palma de aceite, |
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