동일 운전 조건에서 폴리이서술폰 중공사 분리막을 이용하여 혼합 기체로부터 이산화탄소 분리 실험과 수치해석으로 얻어진 결과를 비교하였다. 순수한 기체의 투과도로부터 구한 이상 선택도를 활용한 예측값과 실험값이 많은 차이 가 있음을 확인할 수 있었다. 그러나 이산화탄소 투과도와 선택도를 혼합 기체 분리 실험 결과로부터 구한 후 공급 이산화탄소 몰 분율, 공급 압력과 투과측 압력의 함수로서 투과도와 선택도를 얻을 경우 수치해석 예측값과 실험값이 잘 일치하는 것을 확인하였다.

배기가스로부터 폴리이서술폰 분리막을 이용하여 이산화탄소 분리 특성을 수치해석 방법으로 분석하였다. 공급 기체와 투과 기체가 서로 다른 방향으로 흐르는 향류 흐름 시스템에 대한 분리막 공정 지배 방정식을 유한 차분법으로 전개하였으며 Compaq Visual Fortran 6.6 소프트웨어를 이용 공정 모사하였다. 개발된 프로그램을 사용하여 수치해석을 수행한 결과 이산화탄소 투과특성에 영향을 주는 가장 중요한 인자로는 이산화탄소 투과 구동력과 체류시간임을 알 수 있었다. 동일한 조건에서 향류 흐름 공정모사에 의한 투과 측 이산화탄소 농도와 투과량은 병류 흐름 공정모사 결과보다 소폭 증가함을 확인하였다.

This research was performed with the subject of 111 offices in a chemical plant of Korea. Airborne concentration level of carbon dioxide, carbon monoxide, formaldehyde and total suspended particulates in the office rooms were measured along with temperature and relative humidity. Simultaneously, general characteristics and subjective health symptoms of 500 office workers were investigated through a questionnaire consisting of the five point weighting method : 0 = not at all, 1 = a little bit, 2 = moderately, 3 = quite a bit and 4 = extremely. Results showed that the mean values for temperature and relative humidity in investigated office rooms were 22.2℃ and 34.3%, respectively. The concentrations of formaldehyde, PM10, carbon dioxide and carbon monoxide were 0.17 ppb, 28.8 ㎍/㎥, 0.95 ppm and 424 ppm, respectively. 56.4% of all the workers investigated replied with a sense of fatigue or weariness (mean=2.23), drowsiness or languidness (mean=2.22), sneezing (mean=2.11) and ophthalmia oreye fatigue (mean=2.07). Female workers, non-smokers, non-drinkers, workers who do shift more than nine hours a day, and workers in poor health experienced more subjective symptoms than other workers (p<0.05). Subjective symptoms of office workers were significantly associated with the following items of office characteristics: the purchase date of office equipment, the change of office furniture, the use of paint, smoking in the office, ventilation condition, the use of an individual air-conditioner, the use of a fax machine, the degree of office repair, the proportion of workers per office, the degree of satisfaction in office environment, and the operation hours of the air-conditioner. Also, subjective symptoms were positively correlated with indoor environmental factors such as relative humidity, carbon dioxide level, level of PM10, and formaldehyde (p<0.05). In conclusion, office characteristics and air quality in a chemical plant affected subjective health symptoms of office workers. Thus, in order to improve the health of workers, to enhance work efficiency, and to establish a better office environment, air quality control in office rooms by optimal ventilation, adequately occupied number of workers in one office, and maintenance of office equipment should be fulfilled thoroughly. keywords：Air quality, Subjective health symptom, Formaldehyde, PM10, Carbon monoxide, Carbon dioxide

이산화탄소에 대한 가소화 안정성 및 이산화탄소/질소의 분리특성이 탁월한 폴리이서술폰(PES)중공사 분리막에 의한 이산화탄소 분리특성을 수치해석으로 알아보고자 하였다. 공정변수에 따른 이산화탄소 분리 거동을 예측하기 위하여 공급 기체와 투과기체가 같은 방향으로 흐르는 병류 흐름에 대한 분리막 공정 지배 방정식을 5차 Runge-Kutta-Verner 방법을 사용하여 Compaq Visual Fortran 6.6 소프트웨어를 이용 공정모사 프로그램을 개발하였다. 개발된 프로그램을 사용하여 수치해석을 수행한 결과, 이산화탄소 투과특성에 영향을 주는 가장 중요한 인자로서 공급 이산화탄소 분압, 투과측과 분리막 내부의 압력비 그리고 공급 기체가 분리막 내부에 머무르는 체류 시간임을 알 수 있었다.

Activated carbons were obtained by activating wild cherry stones with different concentrations of phosphoric acid or zinc chloride at different temperatures. The adsorption of N2 at 77 K and of CO2 at 273 K was followed and the data were analyzes by considering different adsorption models. The activated carbons obtained measured high surface area with the most of the surface in all samples located in micropores. Fair agreement was found between the nitrogen surface areas calculated from the BET-, t-, α- and DR- methods, although the first three are based on surface coverage whereas the latter is based on micropore filling. The carbon dioxide surface areas calculated by the DA equation were smaller than the comparable nitrogen areas. This was ascribed to domination of surface coverage mechanism, the absence of activated diffusion process. Based on this explanation the CO2-surface areas as calculated by DA equation should be taken with great reservation.

본 연구에서는 준 회분식 교반조를 사용하여 polybutene (PB)와 polyisobutylene (PIB)고분자를 용해한 벤젠 용액을 연속상, 물을 불연속상으로 구성한 w/o 에멀션액막에 CO2을 흡수시켜 흡수속도를 측정하였다. 점탄성을 나타내는 Deborah 수를 사용하여 점탄성 비뉴튼액체에서 구한 부피물질전달계수 (kLa)를 고찰하고, 수용액에 첨가한 2-amino-2-methyl-1-propanol(AMP)와 CO2의 반응 메카니즘을 해석하였다.

This paper describes to evaluate the performance of ventilation as a change of CO2 concentration with ventilation rate under 35 occupants in a school classroom. Variations of the CO2 concentration as a function of time are measured at center point of classroom with air ventilation rates by the CO2 gas monitor. For 800 m3/h of ventilation rate in the classroom, the average CO2 concentration is 913 ppm. The ventilation rate is sufficient to meet acceptable indoor air quality (≤ 1,000 ppm of CO2, KS school standard) in the classroom of 35 students.

Extraction of Sedum sarmentosum Bunge by super critical carbon dioxide was operated under 40-50℃and 200-250 atm, thus, yield of extraction was very low as 4 wt%. Rats were administrated with the extract orally once a day for succesive 6 days, followed by treatment with carbon tetrachloride (CCl4) on the sixth day. The activities of aminotransferase, alkaline phosphatase, γ-glutamyl transpeptidase, lactate dehydrogenase and contents of triglyceride, total cholesterol in the extract-pretreated rats were decreased compared to the CCl4controled rats, whereas content of HDL-cholesterol was increased. Especially content of hepatic malondialdehyde (MDA) and atherogenic index (AI) were decreased and HTR was increased in the extract-pretreated rats, and reduced peroxidative liver damage in the CCl4-induced hepatotoxicity rats. In addition, activities of hepatic superoxide dismutase, catalase, glutathione peroxidase in the extract-pretreated rats were significantly decreased compared to the CCl4 controled rats, but the content of glutathione was significantly increased. These results suggest that extract of Sedum sarmentosum Bunge has hepatoprotective effect in the CCl4-intoxicated rats.

The effect of CO2 concentration (500, 3,000, 6,000㎕/ℓ) on the mycelial growth and fruit body primordium formation of Ganoderma lucidum on nutrient agar medium was examined. Optimum CO2 concentration for vegetative growth was above 3,000㎕/ℓ. Fruit body initiation was accelerated at higher than 3,000㎕/ℓCO2 exposure but the maximum number and size of primordia, and primordium color were not influenced by CO2 concentrations. Whereas each atypical fruiting structure forming stock culture showed different fruiting time under each concentration of CO2 exposure.

Structural changes of high modulus carbon fiber by oxidation in carbon dioxide gas using SEM, TEM, and XRD have been observed. It was shown that the originally high modulus carbon fiber is composed of highly ordered graphitic crystalline area and non-crystalline area. It was observed that the La increases during the whole oxidation process. It was shown that the oxidation of high modulus carbon fiber initiates at the non-crystalline area and at the ends of fiber. The large pores developed in fiber by direction of fiber length at high temperature (1,100℃), and the small pores developed on the fiber surface at low temperature (900℃). In conclusion, it is found that the oxidation of the carbon fiber was progressed through the imperfection.

Two types of carbon fiber based high modulus- and isotropic-pitch were exposed to isothermal oxidation in air and CO2 gas and the weight change was measured by TGA apparatus. The kinetic equation was introduced f=1--(-atb) and the constant b was obtained in the range of 1.02~1.68 for the isotropic fiber and obtained 0.91~1.93 for the high modulus fiber respectively. In considering the effect of the atmosphere for isothermal oxidation, the value of the constant b obtained in the carbon dioxide was higher than that obtained in the air. Therefore, it was found that the pitch based carbon fiber shows sigmoidal characteristic when it is oxidized in the carbon dioxide. In addition, it was also found that kf = 0.5, which was reaction constant at f = 0.5, was a very useful parameter for evaluation of the oxidation reactivity of pitch based carbon fibers. According to the consideration, it is suggested that the conversion-time curves of the pitch based carbon fibers are correlated by normalized equation f=1--(-AτB), where τ=t/tf= 0.5.

Extraction of Natural Artemisia by using super critical carbon dioxide is operated under 40-50℃ and 200-250 atm, thus, conversion rate is very low as 7wt% while high energy is being wasted. When Natural Artemisia Extract is applied in the control of microbe, concentration and reaction time greatly affected to the growth of microbe. Especially, when refined oil concentration from Natural Artemisia added more than 1,000ppm, staphylococcus aureus and fungi are terminated completely. Thus, it is proven that Natural Artemisia Extract has antimicrobial effect.

Garlic extract using super-critical carbon dioxide is influenced by temperature and pressure, and the optimum condition can make under super-critical state. We can know the defects in process of super-critical extration, It can indicate the drop of product rate, energy loss and equipment expense etcs. The minimum inhibition concentration of microbe which garlic extract contains has apperared the concentration more than 800ppm in this experiment. According to the result of this experiment, we can know that the antibiosis effect in the microbe of staphylococcus and fungus has disappeared in the incubation time more than 12 hours.

본 총설에서는 지구온실기체인 배가스내의 이산화탄소의 분리기술중 가장 잠재성이 큰 막분리기술에 관해 기술하였다. 고분자막에 대한 기체투과(용해확산)이론과 이산화탄소/질소의 물리적인 특성을 배경으로, 많은 문헌에서 발표된 고분자소재의 투과데이터를 분석하고 이를 통해 고분자막의 물리화학적인 구조와 이산화탄소/질소의 투과선택성의 상관관계를 설명하였다. 상업적으로 기체분리에 가장 널리 사용되는 중공사막모듈의 및 분리막공정의 동향에 대해 소개하였다. 마지막으로 국내외에서 발표된 이산화탄소/질소 분리막에 대한 현재까지의 연구동향과 앞으로의 전망에 대해 기술하였다.