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부가결정화를 이용하여 납사분해유의 C9 방향족 혼합물로부터 Pseudocumene 분리
유승곤,이철호,김광주 한국화학공학회 1992 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.30 No.6
부가결정화 기술을 이용하여 납사분해센타에서 부생되는 C_9 방향족 혼합물로부터 pseudocumene을 분리하였다. 원료투입비, 결정화온도, 용매비, 냉각속도 등을 변수로 하여 thiourea 부가특성을 조사하였으며, pseudocumene을 분리할 수 있는 최적조건을 조사하였다. Pseudocumene은 C_9 방향족 혼합물로부터 4단계 부가결정화 조작에 의해서 99.7 wt%의 순도로 분리될 수 있었다. Trimethylbenzene 이성체에 대하여 thiourea에 부가되는 경향은 pseudocumene>hemimellitene>>mesitylene의 순이었다. C_9 방향족 화합물의 이성분계에 대한 부가결정화의 분리도를 추출결정화 및 증류의 분리도와 비교하였다. 이들 이성분계에 대하여 부가결정화에 의한 분리정도(extent of separation)는 한 이론 증류단수의 최대분리정도 보다 5.4-24배 컸으며, 추출결정화에 비해 1.9배 컸다. 또한 부가결정화의 한 단(stage)에서 분리할 수 있는 thiourea의 포획도는 추출결정화에 비해 6배정도 컸다. The separation of pseudocumene from the C_9 aromatic raffinate found in naphtha cracker was studied using adductive crystallization with thiourea. The characteristics of thiourea adduction are investigated on the variables of feed ratio, temperature, solvent ratio and cooling rate, and optimum conditions on the separation of pseudocumene are investigated on these variables. Pseudocumene can be separated by four stages adductive crystallization from C_9 aromatics as a purity of 99.7 wt%. With the trimethylbenzene isomers, the tendency for thiourea adduction is pseudocumene>hemimellitene>>mesitylene. The separation capacities of adductive crystallization for two binary mixtures of C_9 aromatics were compared with those of distillation and extractive crystallization. The extent of separation by one adduction is approximately 5.4 to 24.0 times greater than maximum separation that could be obtained by one theoretical distillation stage. The entrapping capacity is approximately 6.0 times greater than the entrapping capacity that could be obtained by extractive crystallization.
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유승곤,고경렬,채주승,정종헌,이보성 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.1
석유 핏치로부터 hollow 탄소섬유를 만들고 이를 스팀으로 활성화하여 비표면적이 800-2100 ㎡/g인 새로운 타입의 흡착제, 중공활성탄소섬유(HACF)를 제조하였다. 이들의 등온흡착곡선은 모두 Type I을 보였다. 약 70%의 burn-off에서도 외부표면적은 전체표면적의 약 1.5% 미만이었고, 이것은 내부 세공부피가 대단히 큼을 보여주고 있다. HACF는 ACF와 마찬가지로 요오드 흡착이나 메틸렌블루 탈색 등 액상흡착에서 뛰어난 흡착능력을 보여 주었다. 특히 hollow ACF는 분자체와 마찬가지로 혼합물의 분리 등에 효과적으로 사용될 수 있을 것으로 전망된다. Hollow carbon fiber was prepared from petroleum pitch and activated by steam for the production of new type adsorbent. The hollow activated carbon fibers (HACF) showed 800-2100 ㎡/g of specific surface area. All the adsorption isotherms of HACFs were Type I. The external surface area of 70% burn-off HACF was only about 1.5% of total surface area, which means that the micropore volume is very large. HACFs have excellent iodine adsorption and methylene blue decolorization capacities like an ordinary activated carbon fibers in solution. Especially, it is expected that HACF can be used for the separation of various mixtures as molecular sieves.
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향류식 열교환기에 의하여 멸균된 된장의 미생물군 및 색도
유승곤,김인호,김종생,최성현,오만진,김용국,이인기 한국생물공학회 1998 KSBB Journal Vol.13 No.6
To develop a large scale countercurrent single pass heat exchanger for continuous transportation and sterilization of soybean paste, microflora and color value of sterilized soybean paste were examined at various sterile condition. Aerobes, anaerobes, molds, yeasts and lactic acid bacteria were 5.1 x 107 CFU/g, 7.1 x 107 CFU/g, 2.6 x 105 CFU/g, 4.3 x 106 CFU/g, 1.3 x 107 CFU/g, respectively in raw soybean paste. In gold band ampoule test, aerobes and anaerobes of soybean paste were viable up to 90$^{\circ}C$, but become unviable at 100$^{\circ}C$. Molds decreased rapidly and yeasts decreased slowly from 70$^{\circ}C$. Lactic acid bacteria were unviable at 60$^{\circ}C$ within 10 min. In color test, Hunter L, a, and b values of soybean paste were 50.2, +5.6, and +17.8, respectively. After heating in polyethylene film bag at 80$^{\circ}C$, Hunter values were not so much changed and become 50.2, +4.7, and +19.7, respectively. The micorflora and color of soybean paste sterilized in a large scale heat exchanger system resulted in very similar to those of gold band ampoule and polyethylene film bag by effective heat transfer.
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유승곤,엄상용 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.1
Ag, Cu와 Co를 각각 1 wt% 함유시킨 석유 핏치계 활성탄소섬유를 제조하고, 이들의 수중 페놀에 대한 흡착능력을 평가하였다. Ag, Cu함유 활성탄소섬유는 20Å 미만의 미세공이 발달하는데 비하여 Co함유 활성탄소섬유는 미세공과 함께 30-40Å, 200-300Å의 두 중기공 영역이 발달하였다. 요오드 흡착력은 Ag함유 활성탄소섬유가 우수하였으며, 메틸렌블루와 같은 고분자의 흡착은 Co함유 활성탄소섬유가 효과적이었다. 금속함유 활성탄소섬유의 페놀흡착속도는 활성탄에 비하여 18-180배 빠르며, 제거율도 우수하였다. 파과점에서 페놀의 흡착량은 금속을 함유하지 않은 활성탄소섬유가 86.4㎎/g인데 비하여 Cu함유 활성탄소섬유는 152.4 ㎎/g으로 약 1.8배의 흡착능력을 보였다. 1 wt% Ag, Cu and Co-containing Activated Carbon Fibers(ACFs) were prepared and the adsorption abilities of each ACFs for phenol from aqueous solution were investigated. 1'he average pore diameter of Ag and Co-containing were 20Å, while Co-containing ACF have shown two mesopore regions of 30-40Å and 200-300Å with micropores. Iodine adsorption capacity of Ag-containing ACF is much better then that of other ACFs. The Co-containing ACF with mesopores is more efficient than other adsorbents for the adsorption of polymer such as methyleneblue. The adsorption rate of metal-containing ACFs for phenol is 18-180 times faster than that of Activated Carbon(AC). The adsorption amount of phenol on Cu-ACF at breakpoint was 1.8 times larger than that of non metal-containing ACF.
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劉承坤,任洪彬,周赫鍾 충남대학교 1977 工業技術開發硏究所論文集 Vol.4 No.1
In the extraction of RNA from Sccharomyces cerevisiae, sodium chloride solution is regarded as the proper solvent and 5 percent is selected as the optimal concentration. The optimal temperature and time in the extraction of RNA are obtained at 65℃ for 60 minutes. The amount of solvent per unit gram of yeast is scarcely affected at more than 200ml. Yeast powder which was pretreated with hot TCA products about 10 times of RNA than yeast cake. In the case of yeast cake, the amount of RNA extracted was suddenly increased over the sterilizing temperature of yeast. Although yeast was pretreated with hot TCA, the amount of RNA extracted is only 66% of total amount of RNA by the first stage. But 93% of RNA is extracted by the continuous two stages.
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劉承坤 연세대학교 대학원 1974 원우론집 Vol.2 No.1
Abstract The extraction efficiency of reddish-brown pigment from the chestnut-bur was greatly depended upon the extraction time, temperature and the amounts of solvent used. From the experimental results, the amounts of extracted pigment was logarithmically propertional to the extraction time and the amounts of solvent used for the extraction and also linearly proportional to the temperature of extraction, as the following equation which was empirically determined. Ptotal = 0.32logθ+0.485logS+0.022T-0.34 In addition to these, it wart very efficient that the sample was dried at 110℃ for 20minutes, prior to the pigment extraction. Finally, the most optimum conditions of pigment extraction were determined as 60 minutes of operation time, 60℃ of temperature and 400ml of solvent, 20% elhyl-alcohol per 1 g of the sample in the extractions.
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