• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2004년도 추계학술대회
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• pp.280-283
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• 2004

Effect of H2 spillover rate as function of reduction temperature on reaction kinetics was evaluated. Reaction kinetics including yield, conversion, activation energy and selectivity of 1-butene isomerization over Pt/HxMoO/SiO were measured as reaction temperature was increased. While conversion of 1-butane was decreased, yield of iso-butene was increased. Two kinds of reaction mechanism were proposed from the change of selectivity as function of temperature.

• 에너지공학
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• 제15권1호
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• pp.52-59
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• 2006

본 연구에서는 배리어 방전을 이용한 메탄전환 반응에서 수소 및 다른 탄화수소류 화합물의 생성율과 분포에 관하여 알아보았다. 반응기의 외부전극과 내부전극은 SUS로 만들어진 원통형을 사용하였으며, 배리어 방전을 일으키기 위해서 전극 사이에 알루미나 튜브를 사용하였다. 전환된 메탄으로부터 다양한 생성물을 얻기 위해서 유입가스의 조성, 유량변화, 주파수 및 전압을 변화시켜 주면서 실험하였다. 플라즈마 반응에 의한 주요한 생성물들은 에틸렌, 에탄, 프로판, 부탄, 수소, 일산화탄소, 그리고 이산화탄소 등으로 나타났다. 비활성 가스의 사용과 인가전압의 증가에 의해서 메탄 전환율 및 탄화수소류의 선택도가 향상되었다. 유입가스 내에 수증기의 첨가로 인해서 메탄의 전환율 및 수소의 수율이 증가되었다. 수증기 첨가 반응에서 에탄, 프로판 그리고 부탄은 더 높은 전압을 인가하였을 때 수율이 증가하였으며, 아세틸렌과 에틸렌은 보다 낮은 전압에서 수율이 증가함을 알 수 있었다.

• KSBB Journal
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• 제26권4호
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• pp.347-351
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• 2011

In this study, we investigated the effect of reaction factors on enzymatic hydrolysis of Hizikia fusiforme, which is brown algae in marine biomass resource, using commercial enzymes. The composition of H. fusiforme is 38.9% of reducing sugar, 4.8% of moisture, 17.8% of ash, and 38.5% of others. In the condition of 1-5% substrate, the increase of substrate concentration enhanced the increase of reducing sugar formation; however, the hydrolysis yield did not increase after 24 h. After reaction of 75 h, conversion yield of reducing sugar were obtained to 16.45%, 17.99%, and 14.55% at 1, 2.5, and 5% substrate, respectively. As a result of effect of enzyme amount, the formation of reducing sugar did not show considerable change at 1% substrate. However, in the condition of 2.5% substrate, the great change of reducing sugar formation was observed by the increase of enzyme amount. The conversion yields of reducing sugar were obtained to 18.77% and 22.83% at 1% and 2.5% substrate with 30% enzyme, respectively. As a result of heat treatment of biomass, the high yield was obtained in 2.5% substrate and the yields were increased to 0.06-7.2% by the heat treatment. This result will provide the basic information for production process of biofuels and chemicals from marine biomass H. fusiforme.

• Journal of Microbiology and Biotechnology
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• 제1권1호
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• pp.54-62
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• 1991

Cyclodextrin glucanotransferase(CGTase) derived from Bacillus macerans was immobilized by (1) covalent linkage on chitosan and chitin with glutaraldehyde, (2) adsorption on DEAE-cellulose and Amberite IRA 900 after succinylation, and (3) entrapment on alginate and polyacrylamide by cross linking. Adsorption on Amberite IRA 900 and covalent linking on chitosan were identified to be the most suitable immobilization methods considering the yield of activity and stability of immobilized CGTase. The enzymatic properties of immobilized CGTase were investigated and compared with those of the soluble CGTase. Thermal stability of CGTase immobilized on chitosan was increased from 50 to $55^{\circ}C$, and the optimum temperature of CGTase immobilized on Amberite IRA 900 was shifted from 55 to $50^{\circ}C$. The effect of molecular size of soluble starch (substrate) on immobilized CGTase investigated using partially liquefied substrates with different dextrose equivalent(DE). Cyclodextrin(CD) conversion yield augmented according to the increase of DE level for immobilized CGTase on Amberite IRA 900. CD conversion yield of partially cyclized starch with soluble CGTase was higher compared with liquefied one with ${\alpha}-amylase$.

• 한국수소및신에너지학회논문집
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• 제19권1호
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• pp.56-63
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• 2008

In this study, thermochemical degradation of hemicellulose by Acetone-Solvolysis, the effects of reaction temperature, conversion yield, degradation properties and degradation products were investigated. Experiments were performed in a tube reactor by varying reaction temperature from $200{\circ}C$ to $400{\circ}C$ at 40 min of reaction time. The liquid products from pyrolysis-liquefaction of hemicellulose contained various kinds of ketones. ketones, as 4-methyl-3-penten-2-one, 3-methylene-2-pentanone, 22,6-dimethyl-2, 5-heptadien-4-one, 4-methyl-2-pentanone, 5-methyl-2-hexanone, 3,5,5-trimethyl-2-cyclohexen-1-one, and bezenes. as 1,4-dimethylbenzene, 1-methyl-2-(1-methylethyl)-benzene, 1,4-dimethyl-2-(2-methylpropyl)benzene, 4-secbutyl-ethyl benzene, could be used as high-octane-value fuels and fuel additives. Combustion heating value of liquid products from thermochemical conversion processes of hemicellulose was in the range of $6,680{\sim}7,170cal/g$. After 40min of reaction at $400{\circ}C$ in Acetone-Solvolysis of hemicellulose, the energy yield and mass yield was as high as 72.2% and 41.2g oil/100g raw material, respectively.

• 한국수소및신에너지학회논문집
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• 제15권4호
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• pp.333-340
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• 2004

In this study, thermochemical degradation by pyrolysis-liquefaction of cellulose, the effects of reaction time, reaction temperature, conversion yield, degradation properties and degradation products were investigated . Experiments were performed in a tube reactor by varying reaction time from 20 to 80 min at $200{\sim}500^\circ{C}$. Combustion heating value of liquid products from thermochemical conversion processes of cellulose was in the range of 6,920~6,960cal/g. After 40min of reaction at $400^\circ{C}$ in pyrolysis-liquefaction of cellulose, the energy yield and mass yield was as high as 54.3% and 34.0g oil/100g raw material, respectively. The liquid products from pyrolysis-liquefaction of cellulose contained various kinds of ketones, phenols and furans. ketones and furans could be used as high-octane-value fuels and fuel additives. However, phenols are not valuable as fuels.

• Korean Chemical Engineering Research
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• 제50권2호
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• pp.223-228
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• 2012

ABS와 폴리에틸렌(Polyethylene, PE) 및 ABS-PE 혼합물의 저온열분해를 회분식 반응기를 이용하여 상압 및 $450^{\circ}C$에서 실행하였다. 열분해 시간은 20~80분까지 하였고 열분해로 생성된 성분은 지식경제부에서 고시한 증류성상온도에 따라 가스, 가솔린, 등유, 경유, 중유로 분류하였다. ABS와 PE의 혼합 폐플라스틱의 열분해 전환율은 PE의 함량이 증가할수록 증가하는 것으로 나타났다. 열분해생성물의 수율은 PE의 함량이 높을수록 중유 > 가스 > 가솔린 > 경유 > 등유 순으로 회수되었다.

• 약학회지
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• 제27권3호
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• pp.229-234
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• 1983

In the manufacture of precipitated sulfur calcium pentasulfide ($CaS_{5}$, train product) and calcium thiosulfate ($CaS_{2}O_{3}$, by-product) are decomposed simultaneously by hydrochloricacid into coarse (not being uniform) particle-size products. To improve this drawback, calcium thiosulfate was prepared directly without making calcium pentasulfide and obtained $S_{6}$ by the acid-decomposition. In the conversion of hexatomic sulfur to octatomic sulfur, the polymerization and the depolymerization were observed by using purification method. The conversion of $S_{6}$ to $S_{8}$ is proceeded by two steps. The first step reaction is affected by impurities (especially $SO_{2}$ and $H_{2}S$), Hexatomic sulfur is inert to triethylamine for the time being by purification, and thereafter a slow conversion to polymeric and then to octatomic sulfur occurs. Instead of calcium pentasulfide, the acid decomposition of calcium thiosulfate has several advantages; uniformity of particle-size of product, increase of yield, and simplicity of procedure.

• Asian-Australasian Journal of Animal Sciences
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• 제24권5호
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• pp.662-669
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• 2011

An experiment was conducted with broiler (Cobb 400) male chicks (n = 480) to determine the effect of betaine (Bet) supplementation (0 and 800 mg/kg) to diets containing five concentrations (15, 18, 20, 22 and 24 g/kg crude protein, CP) of methionine (Met) in a $2{\times}5$ factorial study for performance, carcass traits, immune responses, and serum parameters. Each diet was fed ad libitum from 1 to 42 d of age to 8 replicates of 6 chicks. Birds were housed in battery brooders placed in an open-sided poultry shed. Body weight gain, feed intake, feed conversion efficiency and slaughter variables were recorded at 21 and 42 d of age. Serum biochemical profile, antibody production against Newcastle disease (ND) and lymphocyte proliferation ratio (LPR) were analysed at 42 d of age. Supplementing Bet to diets containing sub-optimal concentrations of Met (15 g/kg) improved weight gain and breast yield at 21 d of age (p<0.01), and feed conversion efficiency at 42 d of age (p<0.05). Feed efficiency at 21 d of age, body weight gain at 42 d of age, slaughter variables except breast yield at 21 d of age and ND antibody titres were not affected (p>0.05) by the interaction. LPR increased (p<0.05) with Bet supplementation at 20 g Met/kg CP equal to those broilers fed 24 g Met without Bet. Bet supplementation enhanced the concentrations of protein, globulin and cholesterol in serum of broilers fed sub-optimal concentrations of Met. Results suggested that Bet supplementation (800 mg/kg diet) enhanced growth (21 d), feed conversion efficiency (42 d), breast yield and lymphocyte proliferation in broilers fed a diet containing 15 g Met/kg CP.

• 한국토양비료학회지
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• 제46권5호
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• pp.343-350
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• 2013

The objectives of this study were to estimate the potential biomass yield by using the biomass conversion index and evaluate the potential energy production by using the energy conversion index of biomass. Estimating the total biomass yield in Korea showed 9,646.3 thousand tons produced in 2012. Subsequent evaluation of the potential energy production using the estimated biomass yield in 2012 indicated that the calorific values were varied from 3,800 to 4,500 kcal $kg^{-1}$ for crop- and from 4,100 to 4,300 kcal $kg^{-1}$ for woody-based biomass, respectively. Among the examined biomass materials, the pruned branch of a nut tree appeared to be the greatest in bio-energy production showing 6,300 kcal $kg^{-1}$ in calorific value. Total potential energy production from agricultural by-products was estimated approximately at 3,966,000 TOE. Among the agricultural by-products examined, rice straw showed the greatest energy production potential being at 2,321,000 TOE. Furthermore, it might contribute to establishing the countermeasures of biomass utility in agricultural sector based on regional distribution chart of the potential biomass and energy yields in Korea.