SIS-SBS 개질아스팔트 방수시트재 물성 최적화

임광희,Lim, Kwang-Hee 한국화학공학회 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.5

본 연구에서는 방수시트재를 위한 아스팔트의 styrene-butadiene-styrene (SBS)와 styrene-isoprene-styrene (SIS)에 의한 개질에 있어서 자가치유성을 가지는 개질아스팔트 방수시트재의 연화점(softening point), 침입도(penetration), 저온굴곡저항성능(low temperature flexibility), 점도(viscosity) 및 부착성능(adhesion) 등의 물성을 관찰하고, 반응표면분석법(response surface methodology, RSM)을 활용하여 아스팔트 질량 대비 SBS와 SIS의 적정조성을 도출하고 자가치유성을 가지는 개질아스팔트 방수시트재의 물성을 최적화하였다. 고온에서 측정이 수행되는 연화점과 점도는 SBS 또는 SIS의 함량이 증가함에 따라서 유의하게 값이 증가하였다. 그러나 함량 대비 연화점과 점도 증가분은 SBS 경우가 SIS보다 커짐이 관찰되었다. 이러한 원인은 SBS와 SIS의 열적거동의 차이 때문인데, SBS는 고온에서 점도 상승을 동반하는 겔화(gelation)가 되어 가교도가 커지나 SIS는 점도감소를 초래하는 폴리이소프렌 블록의 사슬분리(chain scission) 때문에 사슬꼬임(chain entanglement)이 상대적으로 적어지기 때문이다. 반면에 SIS-SBS 개질아스팔트는 상온에서 측정되는 침입도, 부착성능 및 저온굴곡성능에 대하여, 아스팔트 63 g을 기본으로 SIS 4~5 g과 SBS 8.5 g의 조성에서 최소 탄성거동을 나타내어 최대 침입도 및 최대 부착성능과 최저 저온굴곡성능 값을 보였다. In this study, styrene-isoprene-styrene (SIS)-styrene-butadiene-styrene (SBS) modified asphalt was prepared for waterproof-sheet to measure its properties including softening point, penetration, low temperature flexibility, viscosity and adhesion. Then the properties of SIS-SBS modified asphalt imparted with self-healing were optimized to seek for optimal compositions of SIS and SBS versus asphalt according to response surface methodology (RSM). As the content of SBS or SIS was increased, both properties of softening point and viscosity, measured at high temperature, were increased with a statistical significance. However, the increments of softening point and viscosity per unit content of SBS added, were observed to be greater than those per unit content of SIS added, respectively. It was due to the difference of thermal properties of SBS and SIS at high temperature that the cross-linking degree of SBS was increased by gelation accompanied with the increase of viscosity, while chain-entanglement of SIS was relatively reduced owing to a chain scission of poly(isoprene) blocks causing the decrease of viscosity. To the contrary, SIS-SBS modified asphalt showed a behavior of the least elasticity resulting in both the maximum of penetration and adhesion, measured at room temperature, as well as the lowest low temperature flexibility at the composition of SIS, 4 g and SBS, 8.5 g based on asphalt, 63 g.

폐가스 가습조(유동상호기 및 무산소조)를 포함한 바이오필터공정을 이용한 악취폐가스의 처리

임광희,Lim, Kwang-Hee 한국화학공학회 2018 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.56 No.1

본 연구에서는 폐가스 가습조(유동상호기 및 무산소조)를 포함한 바이오필터공정으로 이루어진 바이오필터시스템을 구축하여, 돈사 및 계사 설비, 퇴비공장 또는 공공시설에서 발생되는 황화수소, 암모니아 및 휘발성 유기화합물을 포함한 악취폐가스에 대한 처리효율을 제고하고 적정 작업조건을 구축하였다. 복합 악취폐가스 처리실험에서, 암모니아 부하의 경우 폐가스 가습조에서 약 75%가 제거되고, 후 공정인 바이오필터에서 20%이상 제거되었다. 톨루엔 부하의 경우 폐가스 가습조에서 약 20%가 제거되고, 후공정인 바이오필터에서 70% 이상 제거되었다. 따라서 물에 용해도가 높은 암모니아의 경우에는 폐가스 가습조에서 주로 제거되었고, 용해도가 낮은 톨루엔의 경우는 바이오필터에서 주로 제거되었다. 한편 황화수소는 폐가스 가습조에서 거의 흡수되어 바이오필터에서 검출되지 않았다. 황화수소 및 톨루엔의 공급을 중단하였을 때에, 암모니아 부하는 폐가스 가습조에서 약 65%가 제거되고 후 공정인 바이오필터에서 나머지 약 35% 정도가 제거되어, 거의 100%의 암모니아 부하가 제거되었다. 폐가스 가습조에서는 암모니아 외에 톨루엔 및 황화수소의 부하가 추가된 복합 악취폐가스의 경우보다 약 10% 더 적게 암모니아가 제거되었는데, 이것은 탈질에 필요한 톨루엔과 같은 유기화합물의 공급 중단에 기인하였다. 바이오필터시스템의 feed가, 1)복합 악취폐가스일 때, 2)암모니아 폐가스일 때에; 기존 폐가스 가습조 용수에 yeast extract를 보충한 경우 또는 yeast extract를 첨가하지 않고 탄소원으로 glucose를 첨가한 경우, 각각의 경우에 폐가스 가습조에서 흡수되는 암모니아질소 흡수율은, 각각 약 0.28 mg/min, 약 0.23 mg/min 및 약 0.27 mg/min으로 산출되었다. 한편 각각의 무산소조에서 탈질율은 0.42 mg/min, 0.55 mg/min, 및 약 0.27 mg/min이었다. 또한 폐가스 가습조(유동상 호기조)의 bubble column 모델링에서 유동상 호기조 단위부피당 bubble의 비표면적(a)과 향상된 물질전달계수(E $K_y$)의 곱의 값은 0.12/hr로 평가되었다. In this research, a biofilter system equipped with a biofilter process and a humidifier composed of a fluidized aerobic and an anoxic reactor, was constructed to treat odorous waste air containing hydrogen sulfide, ammonia and VOC, frequently generated from pig and poultry housing facilities, compost manufacturing factories and publicly owned facilities. Its optimum operating condition was revealed and discussed. In the experiment of complex feed, the ammonia of fed-waste air was removed by ca. 75% and more than 20% at the stage of the humidifier and the biofilter, respectively. The toluene of the fed-waste air was removed by ca. 20% and more than 70% at the stage of the humidifier and the biofilter, respectively. Therefore the water-soluble ammonia and the water-insoluble toluene were treated mainly at the stage of the humidifier and the biofilter, respectively. In addition, hydrogen sulfide was almost absorbed at the stage of the humidifier so that it was not detected at the biofilter process. In the experiment of ammonia-containing feed, the ammonia of fed-waste air was removed by ca. 65% and 35% at the stage of the humidifier and the biofilter, respectively. Its removal efficiency of ammonia at the stage of the humidifier was 10% less than that in the experiment of complex feed, due to no supply of such carbon source as toluene required in the process of denitrification. In the experiments of complex feed, ammonia-containing feed with and without (instead, glucose) the addition of yeast extract, the absorption rates of ammonia-nitrogen were ca. 0.28 mg/min, 0.23 mg/min and 0.27 mg/min, respectively. The corresponding denitrification rates in the anoxic reactor were 0.42 mg/min, 0.55 mg/min and 0.27 mg/min, respectively. In addition, in the modeling of bubble column(the fluidized aerobic reactor of the humidifier) process, the value of specific surface area(a) of bubbles multiplied by enhanced mass transfer coefficient (E $K_y$) was evaluated to be 0.12/hr.

라이포좀의 생성 및 성장 모델링

임광희 ( Kwang Hee Lim ),Yongyi Yin,Sheldon Weinbaum,Shu Chien,David S . Rumschitzki 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.2

고유 Microcrystalline Cellulose를 제거한 리그노셀루로식 바이오매스 액화 폴리올을 성분으로 한 바이오 폴리우레탄 폼의 특성

임광희(Kwang-Hee Lim) 한국고분자학회 2021 폴리머 Vol.45 No.3

바이오매스(톱밥, larix kaempferi)를 액화한 리그노셀루로식(lignocellulosic) 폴리올에서 고유 residue를 제거한 액화 폴리올(액화폴리올 A) 또는 고유 residue뿐만 아니라 고유 microcrystalline cellulose(MCC)도 제거한 액화폴리올(액화폴리올 B)을 사용한 바이오 폴리우레탄(PU) 폼 제조실험을, Lee 등(Polym. Korea 2019, 43, 899-913)의 액화 폴리올을 이용한 바이오 PU 폼 연구에서 제시된 최적 조건과 셀의 크기가 극대화된 공정조건을 실험조건으로 하여서 각각 수행하고, 제조된 바이오 PU 폼의 물성을 비교하여 액화 폴리올 내 고유 MCC의 바이오 PU 폼의 물성에 대한 영향을 분석하였다. 압축강도의 경우에는 액화 폴리올 A를 사용할 때보다 액화 폴리올 B를 사용할 때에 약 20% 정도 감소하였다. 그 이유는 액화 폴리올에서 고유 MCC의, 기계적 강도 향상을 유발하는 충전재 역할과셀의 핵 형성(nucleation) 과정에 관여하는 기능에 기인하였다. 바이오 PU 폼의 셀 크기는 액화 폴리올 A를 사용한 경우보다 셀의 핵 형성 과정에 관여하는 고유 MCC를 제거한 액화 폴리올 B를 사용한 경우에 현저하게 증가함이 관찰되었다. Bio-polyurethane (PU) foams were prepared, using inherent residue-deficient lignocellulosic polyol liquefied from biomass (sawdust, larix kaempferi) (liquefied polyol A) or both inherent microcrystalline cellulose (MCC) and inherent residue-deficient lignocellulosic polyol liquefied from the same (liquefied polyol B), according to the optimal condition and the process condition showing the maximized average size of bio-PU foam cells, suggested in the previous study of Lee et al. (Polym. Korea 2019, 43, 899-913). The characteristics of the bio-PU foams, upon which the effect of inherent MCC in liquefied polyol was investigated, were compared with those in their previous study. Compression strengths of bio-PU foams, prepared using liquefied polyol B were less by ca. 20% than those using liquefied polyol A, which was attributed to the role of MCC as fillers causing the improvement of mechanical strength as well as its function to take part in a nucleation process of each cell. The cells of bio-PU foams prepared using liquefied polyol B were observed by SEM to be expanded and apparently bigger than those using liquefied polyol A.

폐가스내 황화수소 및 암모니아의 동시제거를 위한 semi-pilot 스케일 하이브리드 시스템의 활용

임광희 ( Kwang Hee Lim ),이은주 ( Eun Ju Lee ),박상원 ( Sang Won Park ) 한국공업화학회 2006 응용화학 Vol.10 No.1

폐가스 처리에 대한 바이오필터의 수학적 모델링

임광희(Kwang-Hee Lim) 한국생물공학회 1999 KSBB Journal Vol.14 No.5

One-Sided Nondestructive Evaluation of CFRP Composites By Using Ultrasonic Sound

Kwang-Hee Im(임광희),Gui-Lin Zhang(장계림),Sung-Rok Choi(최성록),Chang-Hee Ye(예창희),Je-Sung Ryu(류제성),Soo-Hwan Lim(임수환),Min-Gui Han(한민규),David K. Hsu 한국생산제조학회 2011 한국생산제조학회지 Vol.20 No.1

It is well known that stiffness of composites depends on layup sequence of CFRP(carbon fiber reinforced plastics) laminates because the layup of composite laminates influences their properties. Ultrasonic NDE of composite laminates is often based on the backwall echoes of the sample. A pair of such transducers was mounted in a holder in a nose-to-nose fashion to be used as a scanning probe on composites. Miniature potted angle beam transducers were used ( Rayleigh waves in steel) on solid laminates of composites. Experiments were performed to understand the behavior of the transducers and the nature of the waves generated in the composite (mode, wave speed, angle of refraction). C-scan images of flaws and impact damage were then produced by combining the pitch-catch probe with a portable manual scanner known as the Generic Scanner (”GenScan”). The pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave to fiber orientation of the CFRP composites, including low level porosity, ply waviness, and cracks. Therefore, it is found that the experimentally Rayleigh wave variation of pitch-catch ultrasonic signal was consistent with numerical results and one-side ultrasonic measurement might be very useful to detect the defects.

방진고무사출성형의 적정설계

임광희 ( Kwang Hee Lim ) 한국화학공학회 2010 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.48 No.4

광촉매 카트리지를 활용한 악취 및 VOC를 함유한 폐가스의 광촉매처리

임광희 ( Kwang Hee Lim ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.1

In this study, the photocatalytic reactor system equipped with photocatalyst-carrying-silica-media cartridges [photocatalytic reactor system (1)] was used to perform the treatment of waste air containing malodor and volatile organic compound (VOC). The result of its performance was evaluated and compared with that of the photocatalytic reactor system equipped with commercial photocatalyst-carrying-nonwoven filter-media cartridges [photocatalytic reactor system (2)]. In case of photocatalytic reactor system (1), at the 1st stage of run the removal efficiencies of ethanol and toluene continued to be 80% and 20%, respectively. However, unlike toluene, the removal efficiency of ethanol dropped to 40% at the end of the 1st stage of run. The removal efficiency of hydrogen sulfide decreased from 100% to 90%. At the 2nd stage of its run the removal efficiency of ethanol decreased to 10% while the removal efficiencies of hydrogen sulfide and toluene remained as same as 90% and 20%, respectively, even though the inlet load of toluene increased by factor of four. In the 3rd stage of its run, as the result of application of aluminium-coated reflector film to the inner wall of photocatalytic reactor system, the removal efficiencies of ethanol and toluene increased by 5% to be 15% and 25%, respectively. In case of photocatalytic reactor system (2), at the 1st stage of its run, the removal efficiencies of ethanol, hydrogen sulfide and toluene continued to be 10%, 97% and 100%, respectively. However, at 2nd stage of its run their removal efficiencies became 5%, 95% and 2~3%, respectively, which showed that the removal efficiencies of ethanol and hydrogen sulfide decreased insignificantly while the removal efficiency of toluene dropped significantly from the perfect elimination. Moreover, the reflector film did not affect the performance of photocatalytic reactor system (2) at all. Therefore the removal of ethanol, hydrogen sulfide and toluene by photocatalytic reactor system (2) was mainly attributed to hydrophobic adsorption of its nonwoven filter media and its extent of photocatalytic removal turned out to be negligible, compared to that of photocatalytic reactor system (1).

악취 및 VOC를 함유한 폐가스의 바이오필터 처리: 1,개선된 바이오필터설계에 의한 압력강하와 미생물 population 분포

임광희 ( Kwang Hee Lim ),이은주 ( Eun Ju Lee ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.1

In this study, both pressure drop and microbe-population-distribution were observed while running a novel biofilter system with improved design in which the biofilter system is composed of two, upper and lower biofilters with both equal feed-rates of up-flow and down-flow, respectively. Then they were compared with the pressure drop and microbe-population-distribution observed in a conventional biofilter of the same effective volume with unidirectional flow. The pressure drop-value of biofilter system with improved design turned out to be less at the incipient stage of run or steady-state long term operation by more than 40~80% of that of the conventional biofilter. The microbe-populationdistribution was observed to be lower and higher at higher and lower column of biofilter, respectively, for both the conventional biofilter and the biofilter system with improved design. The microbe-media of waste-tire crumb showed much greater CFU counts than GAC. In the biofilter system with improved design, the bottom→up feeding of waste air showed greater microbe-population growth than the top→down feeding for both the microbe-media of waste-tire crumb and GAC. However, it was more prominent for the former than the latter. Comparing the microbe-population-distributions of both of the conventional biofilter and the biofilter system with improved design, the microbe-population of latter was distributed ca. 15 and 2.5 times more evenly for GAC and the media of waste-tire crumb, respectively, than that of former.