• Korean Chemical Engineering Research
• /
• v.51 no.3
• /
• pp.335-341
• /
• 2013

Ammonia circulation reactor (ACR) was devised for the effective pretreatment of corn stover. This method is designed to circulate aqueous ammonia continuously so that it can reduce the chemical and water consumption during pretreatment. In this study, ammonia pretreatment with various reaction conditions such as reaction time (4~12 hour), temperature ($60{\sim}80^{\circ}C$), and solid:liquid ratio (1:3~1:8) was tested. Chemical compositions including solid remaining after reaction, lignin and carbohydrates were analyzed and enzymatic digestibility was also measured. It was observed that as reaction conditions become more severe, lignin removal was significantly affected, which was in the range of 47.6~70.6%. On the other hands, glucan and xylan losses were not substantial as compared to that of lignin. At all tested conditions, the glucan loss was not changed substantially, which was between 4.7% and 15.2%, while the xylan loss varied, which was between 7.4% and 25.8%. With (15 FPU-GC220+30 CBU)/g-glucan of enzyme loading, corn stover treated using ammonia circulation reactor for 8~12 hours resulted in 90.1~94.5% of 72-h glucan digestibility, which was higher than 92.7% of $Avicel^{(R)}$-101. In addition, initial hydrolysis rate (at 24 hour) of this treated corn stover was 73.0~79.4%, which was shown to be much faster than 69.5% of $Avicel^{(R)}$-101. As reaction time increased, more lignin removal and it was assumed that the enhanced enzymatic digestibility of treated biomass was attributed to the lignin removal.

• Korean Journal of Food Science and Technology
• /
• v.32 no.4
• /
• pp.902-907
• /
• 2000

Protamine-strong basic protein was prepared from salmon(chum salmon, Oncorhynchus keta) sperm by several pretreatment method. And there were determined yield, amino acid composition, antimicrobial and antioxidant activity of protamine on each pretreatment condition. The yield of protamine was different according to pretreatment, and ultrasonicating, homogenizing and microwaving pretreatment were about 16.0%, 15.5% and 10%, respectively. The main amino acid of P60(microwaving pretreatment for 10 min at $80^{\circ}C$) and UU6(ultrasonicating pretreatment for 60 min at $20^{\circ}C$) were arginine, proline and tryptophan, and arginine content of P60 and UU6 were 61%, 53%, respectively. On the other hand, main amino acid of M(homogenizing pretreatment by mixer) were methionine, proline and arginine, the content were 34%, 28% and 11%, respectively. Also MC(homogenizing pretreatment with $H_{2}SO_{4}$ soln. by mixer) was very different with P60, UU6 and M, the content of MC were proline 44.8% and arginine 39.7%. Prepared protamines showed antimicrobial activity to several gram(+) and gram(-) strain. In particular, the UU6 and P60 protamine has strong antimicrobial activity to Bacillus subtilis and Escherichia coli, and the activity was increased with concentration increasing. Regardless of pretreatment method, all protamine showed antioxidant activity and the $EDA_{50}$ of P60, UU6, M and MC were $101\;{\mu}g/mL$, $410\;{\mu}g/mL$, $523\;{\mu}g/mL$ and $490\;{\mu}g/mL$, respectively.

• Journal of Korean Society for Atmospheric Environment
• /
• v.16 no.2
• /
• pp.191-198
• /
• 2000

For a characterization of the pretreated waste automotive catalyst the following analysis techniques were applied : EA(Elemental Analysis) BET(Brunaure-Emmett-Teller) and ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry). The combustion activity of waste automotive catalyst was investigated for methanol acetaldehyde and toluene as model VOCs in a fixed bed reactor. carbon deposit amount was decreased with increasing catalyst showed a good catalytic activity for VOCs combustion at 40$0^{\circ}C$. Catalytic activity for methanol acetaldehyde and toluence combustion was very excellent and decreased with mileage. The catalytic activity of a waste automotive catalyst for methanol combustion increased after acid treatment. The acid effect of catalytic activity was summarized as follows: HNO3>HCI>H2SO4>CH3COOH. The waste automotive catalyst regenerated by the pretreatment method might have a excellent catalytic activity for VOCs combustion.

• Food Science and Preservation
• /
• v.17 no.4
• /
• pp.507-512
• /
• 2010

The effects of pretreatment by freezing on juice expression and drying characteristics of Prunus mume fruit were investigated. Fresh fruit slices were frozen at $-20^{\circ}C$, thawed, and then either pressed (to yield juice) or dried. Fresh fruit slices were used as controls. Both juice yield and drying rate were higher when pre-frozen fruit was tested, compared to fresh fruit. The L and b color values were lower in the juice and dried powder of pre-frozen compared to fresh fruit. The a color value was higher in juice and powder prepared from pre-frozen fruit compared to fresh fruit. There was no significant difference in free sugar or organic acid content between juices and powders from pre-frozen and fresh fruit. None of soluble solid content, titratable acidity, or juice pH was affected by freezing pretreatment. The results suggest that such pretreatment may be useful to increase juice yield and drying rate. However, browning of juice and powder may be elevated.

• KSBB Journal
• /
• v.29 no.4
• /
• pp.297-302
• /
• 2014

The autoclaving assisted by an irradiation pretreatment method was developed without toxic chemicals to produce fermentable sugars for their conversion to bioethanol. In the first step, electron beam irradiation (EBI) of rice straw was performed at various doses. The electron beam-irradiated rice straw was then autoclaved with DI water at $120^{\circ}C$ for 1 h. A total sugar yield of 81% was obtained from 300 kGy electron beam-irradiated rice straw after 72 h of enzymatic hydrolysis by Cellulase 1.5L (70 FPU/mL) and Novozyme-188 (40 CbU/mL). Also, the removal of hemicellulose and lignin was 32.0% and 32.5%, respectively. This result indicates that the environmentally-friendly pretreatment method of rice straw by an electron beam irradiation could be applied for bioethanol production in plant.

• Korean Chemical Engineering Research
• /
• v.53 no.2
• /
• pp.216-223
• /
• 2015

The present work explores the potential of wet air oxidation (WAO) for pretreatment of mixed lignocellulosic biomass to enhance enzymatic convertibility. Rice husk and wheat straw mixture (1:1 mass ratio) was used as a model mixed lignocellulosic biomass. Post-WAO treatment, cellulose recovery in the solid fraction was in the range of 86% to 99%, accompanied by a significant increase in enzymatic hydrolysis of cellulose present in the solid fraction. The highest enzymatic conversion efficiency, 63% (by weight), was achieved for the mixed biomass pretreated at $195^{\circ}C$, 5 bar, 10 minutes compared to only 19% in the untreated biomass. The pretreatment under the aforesaid condition also facilitated 52% lignin removal and 67% hemicellulose solubilization. A statistical design of experiments on WAO process conditions was conducted to understand the effect of process parameters on pretreatment, and the predicted responses were found to be in close agreement with the experimental data. Enzymatic hydrolysis experiments with WAO liquid fraction as diluent showed favorable results with sugar enhancement up to $10.4gL^{-1}$.

• Korean Journal of Plant Tissue Culture
• /
• v.28 no.4
• /
• pp.189-195
• /
• 2001

This study was carried out to investigate the effects of in vitro culture condition and among lines on growth pattern of lateral buds from nodal cuttings of Phalaenopsis flower stalks. The ratio of bud growing into shoot from nodal cuttings of flower stalks were 90.9% and 54.4% on MS and hyponex medium, respectively. The number of buds grown vegetatively were increased remarkably on the MS medium containing 5 mg/L BA. The rate of buds grown vegetatively was higher in basal and middle parts than in upper part of flower stalks. The flower stalk sections cultured at 25~28$^{\circ}C$ showed the highest ratio of vegetative growth. Medium contamination was decreased by pretreatment of etiolation to the flower stalk. However, the pretreatment did not show specific effects on shoot development and reduction of phenolic compound. Average shoot number which was formed from flower stalk segments in 27 of 30 accessions were 3.17, while high number of shoots were obtained from Phal. 3020 and Phal. 3039. The growth pattern of lateral buds in F$_1$hybrids was similar to that of their parents.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.10
• /
• pp.568-574
• /
• 2017

The purpose of this study was to optimize experimental conditions (time ($X_1$) (ranging of 26.36 - 93.64 min), concentration of sulfuric acid ($X_2$) (ranging of 0-2.5%) and temperature ($X_3$) (ranging of $136.4-203.6^{\circ}C$) for an organosolv pretreatment process to extract lignin from waste wood. The resulting quadratic model equation using RSM (response surface methodology) represented y (lignin yield) = $-79.89+0.91X_1+9.8X_2-2.54{\times}10^{-3}X_1{^2}-2.11X_2{^2}$. The $R^2$ (coefficient of determination) value of 0.8531 for a model indicates this model has statistically significant predictors at the 10% levels. The predictive results optimized by quadratic model produced a lignin yield of 12.46 g/100 g of dry wood under conditions of $178.2^{\circ}C$ and 2.32% $H_2SO_4$. The lignin yield was more affected by the acid catalyst concentrations than the reaction temperature, but the reaction time was not an influential factor for improving lignin extraction from waste wood in this organosolv pretreatment. According to ANOVA (analysis of variance), the significance probability (p-value) of model was smaller than 0.001 and simulation of obtained model equations showed a good reproducibility based on actual organosolv tests under optimal conditions.

• Journal of the Korean Wood Science and Technology
• /
• v.19 no.2
• /
• pp.56-64
• /
• 1991

The destructed chips(Pinus rigida Mill) were sulfonated under different conditions and defiberated. The yields and strengths of pulp, fatty acid and resin acid in sulfonated chips were determined. The results of this work were as follows: 1) A sulfonation caused a yield reduction to 97.9~88.2% at single stage. and to 94.9~88.2% at two stage pretreatment. The pulp yields were rapidly draped with increasing cooking temperature from $130^{\circ}C$ to $150^{\circ}C$ 2) Pulp strengths were improved with iacreasing cooking temperature. A sulfonation with 5% $Na_2SO_3$/NaOH(8/2) at single stage and 2% NaOH-5% $Na_2SO_3$ at two stage were most effective and gave the best combination of strength properteis. 3) Fatty acid esters in chips were mostly consisted of palmitic and olleic acid. During a sulfonation the former increased extensively, and the latter was lost with increase of cooking times. The amount of pimaric type in the chips was relatively decreased by the pretreatnent and abietic-type increased. But the changes between two resin acid types were insignificant. 4) The effciency of pitch removal was dependant upon cooking liquor pH. To remove sufficiently the resinous substance, the chips must be sulfonated at over pH 12. Therefore, taking account of pitch removel, two stage sulfonation is considered suitable as reinforcement pulp for newsprint manufacture from pitch pine chips : 2% NaOH($60^{\circ}C$ 1 hr) at first stage and 5% $Na_2SO_3$ ($130^{\circ}C$, 1hr) at secund stage.

• Food Science and Preservation
• /
• v.4 no.2
• /
• pp.155-162
• /
• 1997

This work was designed to determine the effect of steaming-Pretreatment on Physicochemical and functional properties of roasted Polygonatum odoratum roots. Steaming treatments led to some reduction in the contents of water solubles, such as total solid, reducing sugar and free-amino nitrogen of the unroasted samples. Moreover, roasting processing caused decrease in reducing sugar and free-amino acid, with increase in total soluble solid and browning color of the samples, which showed the dependence of steaming treatment as well as roasting temperature. Electron-donating ability and nitrite-scavenging ratio of the samples were also highly developed along with roasting processing at 17$0^{\circ}C$ within 35min. Considering the physicochemical and some functional parameters of water extracts of roasted samples, roasting at above 14$0^{\circ}C$ for over 55min or at 17$0^{\circ}C$ for around 35min was recommendable for the higher quality of Polygonatum odoritum tea, which conditions were similarly adapted for both steamed and unsteamed samples.