• KSBB Journal
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• v.28 no.1
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• pp.48-53
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• 2013

Pretreatment of wastepaper using aqueous glycerol was investigated to enhance the enzymatic hydrolysis. The effects of four factors (solid/liquid ratio, glycerol concentration, acid concentration, and reaction time) on the dissolution yield, the removal of cellulose, hemicellulose and lignin, and the enzymatic digestibility were examined at $150^{\circ}C$. The 1/8 of solid/liquid was determined to perform the reaction uniformly, and the 93% of glycerol concentration was found to be a minimum concentration to conduct the reaction under atmospheric pressure. Also, it was found that the acid concentration and reaction time were strongly related to the dissolution yield and the removal of cellulose, hemicellulose and lignin, but moderately to the enzymatic digestibility. At an optimum condition of $150^{\circ}C$, 1 h and 1% acid concentration, 56% and 49% of hemicellulose and lignin, respectively, were removed, while only 4% of cellulose was removed. The enzymatic digestibility at this condition was 86%, meaning that 83% of the glucan present in the initial substrate was converted to glucose. Compared to glycerol with ethylene glycol as a pretreatment solvent, glycerol is much cheaper than ethylene glycol, but ethylene glycol is superior to glycerol in delignification.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.395-402
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• 1998

Mori Cortex Radicis, the root bark of mulberry tree, has been used in the treatment of bronchial asthma and other lung diseases in traditional medicine. There was a recent repor t that the water soluble part with molecular weight of above 10,000 has anti-allergic activity. Therefore, we intended to isolate and purify the anti-allergic compound from hot water extract of the Mori Cortex Radicis. Crude extract of Mori Cortex Radicis was prepared by hot-water extraction, and anti-allergic compound was further purified by alcohol precipitation, successive ultrafiltration, anion exchange chromatography and gel filtration chromatography. This compound had homogeneity which was shown by the sharp single peak in HPLC chromatogram (TSK-GEL G400OPW column, RI detector). The molecular weight of the compound was estimated as 23Kda on the basis of calibration curve plotted against protein standards. This compound was identified as complex of sugar, protein and lignin (19.2: 5.9: 72.7), and proteolysis could not decrease the anti-allergic activity but mild delignification decreased the activity remarkably. Therefore, we concluded that the anti-allergic compound of Mori Cortex Radicis was a lignin-carbohydrate complex.

• Journal of the Korean Wood Science and Technology
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• v.21 no.3
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• pp.53-60
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• 1993

Substrates used were hardwood-Suwon poplar-(Populus alba${\times}$glandulosa L.) and softwood-pitch pine-(Pinus rigida M.). And these substrates were steam exploded then treated with sodium chlorite at 75$^{\circ}C$ with occasional stirring in order to obtain samples which had different lignin contents and crystallinity. And then this resulting samples incubated with a commercial cellulase derived from Trichoderma ressei. The contents of Klason lignin were decreased as the increasing of the ratio of sodium chlorite in the two species. The effect of hardwood was more effective than that of softwood in the same ratio of sodium chlorite. The minimum contents of Klason lignin were 0.8% and 5.1% respectively. And the crystallinities of cellulose were increased very little as increasing of the ratio of sodium clorite. The hydrolysis extent of the two species were increased as the increasing of delignification. Especially, the hydrolysis extent of hardwood was more higher than that of softwood. The maximum hydrolysis extent were 89.8% and 71.1%, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.5 s.113
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• pp.41-49
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• 2005

This paper deals the effect of anthraquinone (AQ) on the contribution of sulphidity in kraft pulping of sapwood. The pulping conditions namely- active alkali concentration, pulpingtime, temperature and liquor ratio were varied in low ($15\%$) and high ($30\%$) sulphidity. $0.1\%$ AQ was added in the low and high sulphidity pulping with varying active alkali concentration and cooking time. At optimum conditions, low sulphidity kraft process produced about $44\%$ pulp yield with kappa number of about 23. But in high sulphidity kraft process kappa number was reduced to about 20 at the same yield. An addition of AQ reduced alkali requirement by $2\%$ on oven dried raw material and cooking time by 1 hour to produce pulp yield of about $44\%$ at kappa number 20. AQ is more effective in low sulphidity pulping than the high sulphidity pulping. The breaking length of kraft-AQ pulp was slightly higher than that of kraft pulp.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.3
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• pp.43-50
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• 1997

The purpose of this study was to decrease pollutants of effluents from KP bleaching. Multistage bleaching that combined with O, Eo, and C/D stage was conducted, after optimum bleaching conditions of O, Eo, and C/D stage were determined. Moreover the properties for bleached pulps and pollution level of bleaching effluent were measured by each standard method. Due to increase on the brightness and delignification of pulps by O, Eo, and C/D stage bleaching. It was possible that bleaching sequences were reduced from five stage to four stage. In addition to, OC/DEoD and OC/DEopD bleaching sequences had higher brightness than CEDED bleaching sequence. The pulps bleached by O and Eo stage had higher in tensile index than conventional bleaching sequences with the similar results in burst and tear index. While each bleaching sequences had little differences, bleaching sequences with Eo stage had higher in physical properties than with Eop stage. The pollution level measured by Chemical Oxygen Demand(COD), Biochemical Oxygen Demand(BOD) and Color of bleaching effluents were much lower in combined bleaching sequences of O, Eo and C/D stage than that of CEDED sequence. Particularly, a pollution index of bleaching effluents generated by C/DEoDEB and OC/DEopDED bleaching sequences were lower than that from the other bleaching sequences.

• Korean Chemical Engineering Research
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• v.49 no.3
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• pp.292-296
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• 2011

Liberation of fermentable sugars from lignocellulosic biomass is one of the key challenges in production of cellulosic ethanol. Aqueous ammonia cleaves ether and ester bonds in lignin carbohydrate complexes. It is an effective swelling reagent for lignocellulosic biomass. The aqueous ammonia pretreatment selectively reduces the lignin content of biomass. However, at high temperatures, this process solubilizes more than 50% of the hemicellulose in the biomass. Here we conducted a SAA(Soaking in Aqueous Ammonia) process by moderate reaction temperatures at atmospheric pressure using various lignocellulosicbiomass. The optimum condition of this process was 15 wt% of aqueous ammonia at 50 of reaction time during 72 hr. The delignification was up to 60% basis on initial biomass and the enzymatic digestibility was 60-90% for agricultural biomass, respectively.

• KSBB Journal
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• v.30 no.6
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• pp.332-338
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• 2015

The objective of this study was designed to determine the possibility of bioethanol production from wasted medium density fiberboard (wMDF). We were investigated the enzymatic saccharification characteristics using the enzyme (Cellic CTec3) after pretreatment with sodium chlorite. According to the component analysis results, the lignin contents before and after the pretreatment of wMDF (milling using sieve size of $1,000{\mu}m$) was significantly reduced from 31.13% to 4.11%. Therefore, delignification ratio of pretreated wMDF was found to be up to about 87-89% depending on the sieve size. And we were tested to compare the saccharification ratio according to the sieve size of wMDF ($1,000{\mu}m$, $200{\mu}m$), but it was no significance depending on the sieve size. When enzyme dosage was 5% based on the substrate concentration, enzymatic saccharification ratio was obtained up to 70% by maintaining at $50^{\circ}C$ for 72 hours. We could made the substrate concentration of pretreated wMDF ($1,000{\mu}m$) up to 12% and then enzymatic saccharification ratio was 76.8%, also contents of glucose and xylose were analyzed to 77,750 and 14,637 mg/L, respectively.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.34-43
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• 1987

This study was performed to find out the types of linkage of carbohydrates in wood cell walls. To study the structure of linkage of carbohydrates in wood cell walls, we have attempted to find out the method holocellulose preparation and optimum condition of enzyme hydrolysis in holocellulose, and fractionate oligosaccharide with products that hydrolized partly by acetolysis and deacetylation in holocellulose. We have achieved four results. These results as follow; 1. At first. we reacted in wood meal $NaClO_2$ 1g per lignin lg for one hour and then the same of quantity $NaClO_2$ for four hours. Through these experiments, we have developed new holocellulose preparation method which had low loss of carbohydrates and high effect of the delignification. 2. The optimum condition of enzyme hydrolysis of holocellulose which had lignin was 0.005M sodium acetate buffer (pH 5.0). We have achieved 7.2% reducing sugar through the procedure that reactioned 0.01g holocellulose putting enzyme 0.03g for 72 hours. It may be supposed that 5.5% of lignin contained in holocellulose prevented enzyme contaction from holocellulose and so this lignin has resulted in the low efficiency of enzyme hydrolysis. 3. We did not fractionated from oligosaccharides which were preparated by the method of acetolysis and deacetylation in holocellulose. The reason is that holocellulose having a lot of lignin prevented prefectly partial hydrolysis from the method of acetolysis and deacetylation. 4. We attempted analysis of six standard substances through HPLC apparatus having sugar pak 1 column which we have changed flow rate and the column temperature variably. These six standard substances were D-glucose, D-mannose, D-xylose, D-galactose and L-rhamnose, L-arabinose, But sugar pak 1 column was not fitted analysis of four substances because D-galactose, D-mannose, D-xylose, L-rhamnose were agreement with elution time. And so, we could not analize four standard substances with sugar pak 1 column.

• Journal of the Korean Wood Science and Technology
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• v.4 no.1
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• pp.21-27
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• 1976

This study was carried out in order to obtain the effect of active alkali concentration. Sulfidity 25%, maximum temperature 170$^{\circ}C$, cooking time 3hrs., liquor to wood ratio 5 : 1 in the kraft cooking conditions were maintained. Active alkali concentration were varied at intervals of 3% between 12% and 24%. The rates of de lignification increased with an increase in active alkali concentration and beatability, brightness, and strength of pulp also improved. The total pulp yield trand to decrease with an increase of active alkali concentration. The maximum screened pulp yield were obtained between 18% and 21% A.A.. Therefore, the optimum active alkali concentration was 18~21%.

• Journal of the Korean Wood Science and Technology
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• v.39 no.5
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• pp.420-428
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• 2011

The distribution of arabino-4-O-methylglucuronoxylans (AGXs) and O-acetyl-galactoglucomannans (GGMs) in warts and the warty layer of tracheids in normal wood (NW) and compression wood (CW) of Cryptomeria japonica was investigated. Under field emission scanning electron microscope (FE-SEM) observation, warts and the warty layer of delignified NW and CW tracheids were degraded by xylanase treatment, indicating that warts and the warty layer contain high amounts of AGXs. However, the effect of xylanase was not observed in NW and CW tracheids before delignification, suggesting that AGXs in warts and the warty layer may be encrusted with lignin. After ${\beta}$-mannanase treatment, no noticeable changes were observed in warts and the warty layer of NW tracheids, indicating that warts and the warty layer contain either no or very few GGMs. Similar results to FE-SEM observations were also observed with immunogold labeling. AGX labeling was observed in warts and the warty layer of NW and CW tracheids, while GGM labeling was not detected. NW tracheids showed a much stronger density of AGX labeling than did CW tracheids in warts and the warty layer, indicating differences in the chemical compositions of warts and the warty layer between NW and CW tracheids.