• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.61-67
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• 1970

The growth characteristics of Candida tropicalis KIST 359, isolated from soil samples collected at an oil depot in Korea, have been studied by cultivating batches under varying conditions. The conclusions of the study were: 1. The yeast easily assimilates hydrocarbons in a range of $C_{14}-C_{17}$, and the optimum cultivation temperature and pH are $30^{\circ}C$ and 5.5, respectively. 2. Using this strain of micro-organism, gas oil gives a higher cell yield than kerosine and with gas oil except urea all other nitrogen sources $(NH_4NO_3,\;NH_4Cl,\;(NH_4)_2SO_4\;and\;(NH_4)_2HPO_4)$ similarly support a satisfactory growth of the yeast. 3. The highest yield is obtained with a gas oil level of 10%(v/v), and concentrations of nitrogen source and $MgSO_4{\cdot}7H_2O$ of 0.5 and 0.05%(w/v), respectively. 4. The protein content of dried yeast cells is 59.8%. Its amino acid composition can be compared well with that of FAO provisional patterns, but with a low methionine and a high lysine content.

• Applied Chemistry for Engineering
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• v.35 no.5
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• pp.410-417
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• 2024

Steel mill gases, including coke oven gas (COG), blast furnace gas (BFG), and Linz-Donawitz gas (LDG), are mainly used as fuels within steel plants, resulting in substantial CO₂ emissions. This combustion process accounts for 10% of South Korea's total CO₂ emissions. These off-gases, rich in CO, CH₄, and hydrogen, have the potential to be converted into valuable chemicals through catalytic processes, thereby reducing CO₂ emissions and increasing their economic value. This study investigates the conversion of steel mill gases into methanol, an important platform chemical and cleaner transportation fuel. By using COG and LDG as sources of CO and H₂, respectively, a novel process was developed. In this process, H₂-rich COG from a simple single-step membrane separation and raw LDG are converted into methanol with high selectivity using a Cu-Zn-Al catalyst. The study identified the optimal gas compositions for methanol production through experimental results, demonstrating efficient methanol synthesis from various compositions of LDG, COG, pure hydrogen, and H₂-rich COG. This innovative approach not only aims to reduce specific CO₂ emissions from steel plants but also enhances the economic value of the byproduct gases. Thus, the study provides a sustainable and economically advantageous solution for the steel industry.

• Applied Biological Chemistry
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• v.14 no.1
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• pp.9-18
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• 1971

In order to obtain basic information on the production of single cell protein from petroleum, more than 400 yeast strains were isolated from various soil samples in Korea utilizing petroleum hydrocarbon as the sole carbon source. A yeast strain showing the highest cell yield among the isolated strains was selected and identified. The optimal culture condition was searched in the flasks shaken throughout the procedure. And the growing characteristics for the selected yeast strain and chemical analysis of the yeast cell component were carried out. The results obtained were as follows: 1. The selected yeast strain was identified as Candida curvata and we named it Candida curvata-SNU 70. 2. The composition of the medium proposed for the present yeast strain is: Light Gas Oil 30ml, Urea 400mg, Ammonium sulfate 100mg, Potasium phosphate (monobasic) 670mg, Sodium phosphate (dibasic) 330mg, Magnesium sulfate 500mg, Calcium carbonate 3g, Yeast extract 50mg, Tween 20 0.05ml, Tap water 1,000ml. 3. Other culture conditions employed for the yeast were pH 5.5-7.0, temp. $30^{\circ}C$ under an affluent aerobic state. 4. Addition of light gas oil in portions to the culture media as the growth proceeded was more effective, especially in the cultivation on the higher oil concentration media. 5. Studies on the propagation of the yeast cells in the light gas oil medium revealed that the yeast has the lag phase lasted 16 hours and the logarithmic growth phase covered 16 to 28 hours. The specific growth rate was about $0.22\;hr^{-1}$ and doubling time was 3.2 hrs. during the logarithmic growth phase. 6. Under the cultural condition employed, the cell yield against the amount of light gas oil (wt%) was 16.1% and the protein content of the dried yeast cells was 48.4%.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.119.1-119.1
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• 2016

크라이오 워터펌프(CWP)는 크라이오 펌프(CP)와 달리 10 K 활성탄 어레이는 장착하지 않고 100 K 정도로 냉각시킨 배플만을 사용하여 물의 배기속도를 최적화 하는 데 초점을 맞춘 진공펌프다. 용기 압력이 10-9 mbar 대가 될 때까지는 잔류기체의 90% 이상이 수분이므로 다른 기체들의 배기 보다는 물을 잘 배기하는 것이 배기시간을 단축하고 도달 진공도를 낮추는 첩경이라는 아이디어에 근거를 두고 있다. CWP는 물 흡착확률을 거의 1에 가깝게 만들어서 오리피스 컨덕턴스에 육박하는 이상적인 펌프를 제작할 수 있지만 용도상 직부형(close type), 통과형(in-line type) 및 내장형(in-vessel type) 등 세 가지 다른 형태에 따라 성능도 약간씩 다르다. CWP는 모든 기체에 반응하는 정통적인 CP에 비해 훨씬 간단하고 저렴하게 만들 수 있으면서도 진공 시스템에 큰 영향을 미칠 수 있지만 물 이외의 기체들을 배기할 펌프가 필요하다는 측면에서 활용에 제약이 있다. 만일 TMP를 이미 사용하고 있거나 작은 TMP를 추가로 달아서 충분히 작동이 가능한 시스템이면서 수분 발생이 많은 곳이나, 또 활성탄의 오염이나 산소 분위기 등 CP 투입이 꺼려지는 환경이라면 CWP 사용이 좋은 선택이 될 수 있다. CWP의 물 배기용량은 CP의 알곤이나 질소 배기용량에 준하는 크기로 0.5g/cm2 이상임이 실험적으로 입증되었다. 따라서 일반적인 상황에서 정상 작동시 대부분의 기체는 TMP로 배출하고 잔류 수분만 포집하므로 CP처럼 주기적인 재생이 필요 없다. 필요하다면 CWP는 금속 표면에 응축된 물을 드라이펌프 작동만으로 쉽게 제거할 수 있고 혹시 오염 물질이 붙어도 세척이 용이하다. 이런 사용상 융통성과 여러 가지 장점에도 불구하고 그동안 물배기에 대한 인식이 미흡하고, 또 부수적이고 추가적인 비용이 드는 것으로 생각되어 주목을 받지 못했지만 디스플레이와 반도체 산업을 필두로 물 분압을 낮추고 생산수율을 높이는 것에 점점 더 관심이 높아지면서 CWP에 대한 수요도 높아지고 있다. 본 보고에서는 20인치 통과형 CWP를 만들고 14인치 TMP에 얹어 복합 진공배기시스템을 구성한 후 물 배기속도와 알곤, 질소 및 수소 배기속도를 측정하고 예측치와 비교했다. 아울러 물 배기용량 측정 및 CWP의 온도제어와 펌프재생 특성 평가 결과도 정리했다.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.153-160
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• 2023

In this study, biochar was produced from biomass waste, and its methylene blue adsorption capacity was evaluated. The major components of the biomass were cellulose, hemicellulose, and lignin. Ash content was high in waste wood. Carbonization yield decreased as carbonization temperature increased, as did hydrogen and oxygen content, but carbon content increased. Increased carbonization temperature also increased the specific surface area and micropores of biochar. At 600 ℃, biochar had the highest specific surface area (216.15~301.80 m² /g). As a result of methylene blue adsorption on biochar carbonized at 600 ℃, oak, waste wood, and pruned apple tree branches fit the Freundlich model, while pruned peach tree branches fit the Langmuir model. In the adsorption kinetics of methylene blue on biochar, oak and pruned peach tree branches fit a pseudo-first-order model, while waste wood and pruned apple tree branches fit a pseudo-second-order model.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.423-429
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• 2009

The purpose of this study is to investigate the optimal condition for the hydrogen-rich gas production and the CO removal by reforming of gliding arc plasma reforming system using biogas. The parametric screening studies were carried out according to changes of steam feed amount, catalyst bed temperature in water gas reactor and catalyst bed temperature, input air flow rate in preferential oxidation reactor. The standard condition is as follows. The steam/carbon ratio, catalyst bed temperature, total gas flow rate, input electric power and biogas composition rate ($CH_4$ : $CO_2$) were fixed 3, $700^{\circ}C$, 16 L/min, 2.4 kW and 6 : 4, respectively. The results are as follow, HTS optimum operating conditions were S/C ratio of 3 and reactor temperature of $500^{\circ}C$. LTS were S/C ratio of 2.9 and temperature of $300^{\circ}C$. Also, PROX I optimum conditions were input air flow rate of 300 mL/min and reactor temperature of $190^{\circ}C$. PROX II were 200 mL/min and $190^{\circ}C$ respectively. After having passed through each reactor, the results were as follows: 55% of $H_{2}$ yield, 0% of CO selectivity, 99% of $CH_4$ conversion rate, 27% of $CO_2$ conversion rate, respectively.

• Journal of the Korean Wood Science and Technology
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• v.33 no.3 s.131
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• pp.45-52
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• 2005

This research was performed to evaluate adsorption behavior of woody charcoals obtained from wood powder, fiber and bark of spruce (Abies sibirica Ledeb). The wood materials were carbonized at various temperatures for 1 hour using experimental rotary kiln without any inert gas. The adsorption capacity of iodine and toluene, specific surface area and removal efficiency of acetic acid and ammonia gas of those charcoals were measured. The higher was the temperature for carbonization, the lower yields of charcoals were. Ash content of bark charcoal was higher than that of wood powder charcoal or fiber charcoal. Elemental analysis of woody charcoal revealed that the content of carbon was gradually lincreased as carbonization temperature was higher. When carbonization temperature was higher, adsorption capacity of woody charcoals for iodine was much improved. Wood powder charcoal and fiber charcoal were more effective for iodine adsorption rather than bark charcoal. Capacity of toluene adsorption was the highest in the charcoal of $600^{\circ}C$. Charcoals produced at high temperature efficiently removed acetic acid gas, while charcoals carbonized at low temperature such as $400^{\circ}C$ were proper to remove ammonia gas. This difference may be explained that the acidity of charcoals depends on the carbonization temperature: charcoals of low temperature indicate acidic property, while those of high temperature turned to alkaline.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.684-688
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• 2003

The objective of this study was to search for the best strain as a source of L- $\alpha$-glycerophosphate oxidase (GPO) production and to establish the process technology for the purification of GPO on an industrial scale. The GPO was produced by culturing Streptococcus faecium, and purified by ammonium sulfate, DEAE-cellulose and hydroxyapatite chromatography. The relative activity was 60 units/L for 5. faecim ATCC 12755, 65 units/L for 5. faecium ATCC 19634, and 67 units/L for 5. faecium $M_{74}$.LC, respectively. The optimum condition for fermentation was $37^{\circ}C$ for temperature, 300 rpm for stir rate, 0.5 L/min for aeration rate and 17 hours. The main culture medium prepared by the modified AC medium. AC medium consists of 0.1% glucose, 0.2% glycerol, 1.0% tryptone and 1.0% yeast extract, 0.5% $K_2HP0_4$, pH 7.0. The GPO was purified by ammonium sulfate fractionation and ion exchange column chromatography, The yield and purity were 17.2% and 5.3 fold, respectively.

• Clean Technology
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• v.20 no.1
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• pp.57-63
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• 2014

In this work, we performed the methanation with steam and synthesis gas of a low $H_2/CO$ ratio to develop a process for producing SNG (synthetic natural gas). In this experiment conditions, the water gas shift reaction and the methanation reaction take place at the same time, and insufficient supply of steam might cause the deactivation of the catalyst. Therefore, the reaction characteristics with the amount of steam was performed, and the methanation on syngas containing $CO_2$ of the high concentration were studied. As a result, the temperature in the catalyst bed decreased by the supply of steam, and the methanation and the water gas shift reaction occurred at the same time. Although methane yield slightly decreased at the methanation using syngas containing $CO_2$ of the high concentration, the long-term operation (1,000 h) in the experimental conditions of this study indicates that this condition is suitable for the new commercial scale SNG process.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.1-11
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• 2017

Bio-oil has attracted considerable interest as one of the promising renewable energy resources because it can be used as a feedstock in conventional petroleum refineries for the production of high value chemicals or next-generation hydrocarbon fuels. Zeolites have been shown to effectively promote cracking reactions during pyrolysis resulting in highly deoxygenated and hydrocarbon-rich compounds and stable pyrolysis oil products. In this study, catalytic pyrolysis was applied to upgrade bio-oil from yellow poplar and then fuel characteristics of upgraded bio-oil was investigated. Yellow Poplar(500 g) which ground 0.3~1.4 mm was processed into bio-oil by catalytic pyrolysis for 1.64 seconds at $465^{\circ}C$ with Control, Blaccoal, Whitecoal, ZeoliteY and ZSM-5. Under the catalyst conditions, bio-oil productions decreased from 54.0%(Control) to 51.4 ~ 53.5%, except 56.2%(Blackcoal). HHV(High heating value) of upgraded bio-oil was more lower than crude bio-oil while the water content increased from 37.4% to 37.4 ~ 45.2%. But the other properties were improved significantly. Under the upgrading conditions, ash and TAN(Total Acid Number) is decrease and particularly important as transportation fuel, the viscosity of bio-oil decreased from 6,933 cP(Control) to 2,578 ~ 4,627 cP. In addition, ZeoliteY was most effective on producing aromatic hydrocarbons and decreasing of from the catalytic pyrolysis.