• 대한화학회지
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• 제22권5호
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• pp.334-339
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• 1978

${\alpha}$-Bromophenylacetamide를 황산중에서 가수분해시키면 대개의 경우 mandelic acid와 ${\alpha}$-bromophenylacetic acid의 혼합물이 얻어지고, 염산의 경우에는 ${\alpha}$-chlorophenylacetic acid만이 얻어졌다. 그러나 조건을 잘 조절하면 mandelic acid와 ${\alpha}$-chlorophenylacetic acid는 각각 86, 95 % 이상의 좋은 수율로 순수하게 생성되지만, ${\alpha}$-bromophenylacetic acid만을 순수하게 생성시키는 최적 조건은 찾지 못하였다. 즉 이들 조건에서 ${\alpha}$-탄소의 브롬이 각각 $OH^{\Theta}$ 와 $Cl^{\Theta}$로 쉽게 치환되었다.

• 신재생에너지
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• 제9권2호
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• pp.5-14
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• 2013

The efficiency of microwave-assisted acid hydrolysis of seaweeds for the production of ethanol was investigated and its effect on hydrolysis into reducing sugar and fermentation into ethanol evaluated as compared with those by conventional heating. A brown seaweed, Laminaria japonica (10-100g/L) was hydrolysed under dilute acidic condition (0.5N $H_2SO_4$, $100^{\circ}C$) with two sorts of heating: microwave irradiation for ${\leq}10min$ and conventional heating for 10-60min. Microwave-assisted hydrolysis was shown to be more efficient. A similar range of reducing sugar and ethanol yields as with the conventional autoclave heating procedure(${\geq}30min$) was observed, but it was obvious that production of ethanol from microwave-assisted hydrolysis had a 3 times faster reaction rate leading to very short production times, lower energy consumption/loss than from the conventional heating mode, and higher biomass loading without significant reducing ethanol yield, thus microwave-assisted acid hydrolysis is a potential alternative method for more effective hydrolysis of Laminaria japonica.

• Journal of the Korean Wood Science and Technology
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• 제43권5호
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• pp.672-681
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• 2015

As a part of abating the formaldehyde emission of amino resin-bonded wood-based composite panels, this study was conducted to investigate hydrolytic stability of urea-melamine-formaldehyde (UMF) resin depending on various hydrolysis conditions and hardener types. Commercial UMF resin was cured and ground into a powdered form, and then hydrolyzed with hydrochloric acid. After the acid hydrolysis, the concentration of liberated formaldehyde in the hydrolyzed solution and mass loss of the cured UMF resins were determined to compare their hydrolytic stability. The hydrolysis of cured UMF resin increased with an increase in the acid concentration, time, and temperature and with a decrease in the smaller particle size. An optimum hydrolysis condition for the cured UMF resins was determined as $50^{\circ}C$, 90 minutes, 1.0 M hydrochloric acid and $250{\mu}m$ particle size. Hydrolysis of the UMF resin cured with different hardener types showed different degrees of the hydrolytic stability of cured UMF resins with a descending order of aluminum sulfate, ammonium chloride, and ammonium sulfate. The hydrolytic stability also decreased as the addition level of ammonium chloride increased. These results indicated that hardener types and level also had an impact on the hydrolytic stability of cured UMF resins.

• Korean Chemical Engineering Research
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• 제52권2호
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• pp.226-232
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• 2014

본 연구에서는 $120{\sim}150^{\circ}C$에서 다양한 산 촉매에 의한 자이란 가수분해 거동을 조사하였다. 또한 자이란에서 자이로스 생성과 자이로스로부터 푸르푸랄 분해에 대한 kinetic 인자를 분석하였다. 높은 반응온도와 산 촉매 농도는 자이란 가수분해와 자이로스 분해를 촉진하였다. 최대 반응속도상수($k_1$)에 대한 가수분해 조건은 산 촉매에 따라 다르게 나타났다. 황산, 옥살산, 말레산 중에서 자이란 반응속도상수($k_1$)는 황산 100 mM로 $120^{\circ}C$에서 반응하였을 때 $0.0241min^{-1}$로 가장 높게 나타났다. 하지만 황산은 옥살산, 말레산과 비교하여 자이로스 분해를 더욱 유도하여 상대적으로 높은 푸르푸랄을 생성하였다. 자이란 분해에 관여하는 활성화 에너지는 황산에서 가장 높게 나타났다.

• 한국토양비료학회지
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• 제50권6호
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• pp.606-614
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• 2017

Amount of food waste has been increased annually in Korea and re-use of food waste as a fertilizer or soil amendment in agricultural field has been studied. Therefore, main purpose of this research was to determine optimum condition of hydrolysis for food waste management. Three different solvents, HCl, $H_2SO_4$, and KOH, were used and varied concentration at the range of 10~30% and hydrolysis time at the range of 1~3 hours were evaluated. In general, reduction rate of food waste was increased when concentration of solvent and hydrolysis time was increased except when KOH was used. Among different solvents, concentration, and hydrolysis time, the highest reduction rate (97.79%) was observed when 30% of HCl was used with temperature of $140^{\circ}C$ at 2 hours of hydrolysis time. In addition, neutralization effect of alkalic materials, shell waste (SW) and egg shell (ES) was evaluated. Both SW and ES increased pH of finished acid hydrolysis solution up to 7.61 indicating that neutralization effect of SW and ES was sufficient for finished acid hydrolysis solution. Contents of organic matter was also at the range of 10.7~13.04% and 5.53~8.04% respectively when HCl and $H_2SO_4$ were used as solvent. Overall, hydrolysis technique can be used to manage food waste with selected optimum condition in this study and characteristics of finished hydrolysis solution after neutralization might be suitable for soil amendments.

• 한국잠사곤충학회지
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• 제40권2호
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• pp.163-168
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• 1998

Hydrolysis rate and activation energy of Antheraea pernyi silk fiber treated with HCI were examined. Thermal decomposition temperature and surface morphology were also investigated by using differential scanning calorimeter and scanning electron microscope. As the concentration of hydrochloric acid and the treatment temperature increased, the hydrolysis occurred more rapidly. The activation energy of Antheraea pernyi, 74.0 kJ/mol, was higher than that of Bombyx mori, 58.1 kJ/mol. As the concentration of hydrochloric acid increases, the activation energy of Antheraea pernyi decreased from 74.0 kJ/mol to 62.0 kJ/mol. The shape of acid-resistance fraction of Antheraea pernyi became more distroyed and was transformed from fiber to powdered form with an increase of hydrolysis rate. The thermal decomposition temperature of Antheraea pernyi was 360.8$^{\circ}C$ until the hydrolysis rate was 81.8 wt%, but ti decreased to 347.0$^{\circ}C$ when the hydrolysis rate was 93.8 wt%.

• 한국잠사곤충학회지
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• 제42권2호
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• pp.104-108
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• 2000

To hydrolyze insolule sericin the enzyme hydrolysis was used, and then obtained the results as given belows. When insoluble sericin was hydrolyzed by enzyme treatment, the solubility was best at pH 7, 60$\^{C}$ and was slightly increased both above 2 hours treatment and above 10% of enzyme concentration. As the results of electrophoresis, the distribution of molecular weight of sericin powder obtained by enzyme hydrolysis was very weak and showed in the wide range having no distinguishable band. Average degree of polymerzations (A.D.P.) of sericin hydrolyzed by enzyme were about 4.1∼6.3, average molecular weight were about 470∼730. The whiteness of the sericin powder obtained by enzyme hydrolysis was high and increased slightly with higher treatment concentration of enzyme. As the results of amino acid analysis, the amino acid analysis, the amino acid composition of the sericin powder from the enzyme treatment were similar to which located at near 230$\^{C}$ and 320$\^{C}$. The peak of near 230$\^{C}$ could not been found in the sericin powder obtained by enzyme hydrolysis.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.27-28
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• 2013

• Weed & Turfgrass Science
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• 제2권2호
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• pp.176-183
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• 2013

담수조류인 그물말 (Hydrodictyon reticulatum, HR)의 실용적 당화조건 확립을 위해 산 가수분해 방법으로서 one-step acid hydrolysis과 two-step acid hydrolysis, 그리고 산가수분해 후 효소가수분해를 병행하는 combined hydrolysis를 검토하였다. One-step acid hydrolysis의 경우, $120^{\circ}C$에서 HR 4% 고형분을 2% 황산 용액에 넣어 1시간 동안 반응시킬 경우가 적정하였다. Two-step acid hydrolysis의 적정조건은 1차 가수분해시 HR 건조중: 72% 황산을 1 g : 1.5mL로 하여 $60^{\circ}C$에서 1시간 반응시킨 다음, 증류수 23.5 mL를 첨가하고 $120^{\circ}C$에서 1시간 가수분해시키는 것이었다. Combined hydrolysis의 경우, 2% 염산에 25%의 HR 고형분을 넣고 $120^{\circ}C$에서 1시간 반응시킨 후, citrate buffer로 4% 고형분 함량이 되도록 희석하고 E1+E2 효소를 각각 1+0.2 mL g $DM^{-1}$ 수준으로 첨가하여 $50^{\circ}C$에서 1~2일 동안 반응시키는 것이 바람직하였다. Glucose 생성량, 발효억제물질(HMF, furfural) 생성량, 강산 사용제한 등을 종합적으로 감안할 때, combined hydolysis가 보다 유용할 것으로 판단되었다.

• 농업과학연구
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• 제36권2호
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• pp.225-232
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• 2009

The ratio of saccharification and formation of furans during the acid hydrolysis of agar with oxalic acid and sulfuric acid were examined base on the contents of the agar and acids. The ratio of saccharification in oxalic acid appeared to be 51~59% somewhat higher than 49~61% of sulfuric acid. Formation of the furans during the acid hydrolysis increased proportional to the contents of agar and acid. The relative formation ratio was high 10~47% for furfural (FUR) and 15~29% for hydroxy-methyl furfural (HMF) in 0.5~1.25% sulfuric acid rather than those of oxalic acid. When comparing the removal efficiency of the furans using an alkali treatment, steam stripping and hydrophobic resins, FUR was eliminated 60% by the alkali treatment, 62~90% by steam stripping and 71~75% by Amberlite XAD4 and 7HP, while HMF was removed to low levels of 10.5%, 4~17% and 13~25%, respectively. The loss of reducing sugar was also observed in process of the removal of furans, and the loss rate was the level of 2~4% in alkali treatment, 11~16% in steam stripping and 7~9% in Amberlite resins.