포말 분리법에 의한 효모의 회수

안수현,서근학,김병진 釜慶大學校 1998 釜慶大學校 論文集 Vol.3 No.2

Foam separation of microbial cell of the yeast Saccharomyces formosensis was investigated. A batch foam or continuous separator has been used to recover the yeast cells from the culture broth without the use of surfactant. In continuous experiments, the yeast concentration ratio was enhanced at low hydraulic residence time, high superficial gas velocity or low influent yeast concentration. And addition of Ca2+ also improved the concentration ratio. "The optimum pH and temperature for foam separation was the same as the optimum condition for ethanol production.

고정화 질화세균의 암모니아 제거속도식

김병진,이정훈,서근학 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.1

본 연구는 polyvinyl alcohol에 고정화한 질화세균군을 이용하는 공기 부상식 생물반응기의 총 암모니아성 질소(total ammonia nitrogen, TAN) 제거속도식을 도출하고자 하였다. 유입 합성폐수 내의 TAN 농도는 5g/m^3, 온도는 25℃를 유지하여 0.05-1.0hr의 수력학적 체류시간에서 실험하였다. TAN제거속도식은 Monod 식과 잘 일치하였으며 얻어진 최대 TAN제거속도, R_max와 반포화상수, K_s는 각각 640g/m^3·day, 1.667g/m^3이었다. 0.6-4.8g/m^3의 농도 범위에서는 1/2차 속도식도 TAN제거속도식으로 적합하였다. 본 공정을 정수처리 공정에 적용시킬 경우 6g/m^3의 농도를 가지는 원수를 TAN의 음용수 처리기준 이하로 유지하기 위해서 0.9hr의 수력학적 체류시간이 필요할 것으로 추정되었다. 높은 제거속도를 하는 공정에 적용시킬 경우 수력학적 체류시간을 감소시킬수록 높은 제거속도를 얻을 수 있는 것으로 나타났다. The kinetics parameters for total ammonia nitrogen(TAN) removal in a airlift bioreactor using nitrifier consortium entrapped in polyvinyl alcohol(PVA) were evaluated by using a synthetic wastewater at 25℃. Influent TAN concentration were 5.0g/m^3 with hydraulic residence time(HRT) ranging from 0.05 to 1.0 hr. TAN removal rate followed Monod kinetics in overall concentration range and maximum TAN removal rate and half saturation constnat were 640g/m^3·day and 1.667g/m^3, respectively. For TAN concentration ranging from 0.6 to 4.8 g/m^3, the TAN removal rate can be described by half order kinetics. If this process applied to the water treatment process(influent TAN concentration: 6g/m^3), 0.9 hr of HRT was required for drinking water quality of TAN. To get high TAN removal rate, a low HRT was favorable.

역유동층 반응기와 삼상유동층 반응기를 이용한 유기물 제거에 관한 연구

박영식,안갑환,추석열,서근학,송승구 부산대학교 1995 生産技術硏究所論文集 Vol.48 No.-

구형의 섬유상 플라스틱을 media로 사용하여 3상 유동층 생물막 반응기와 역유동층 생물막 반응기로 유기물 제거효율을 비교 실험하였다. 유입수의 SCOD가 1800㎎/L였을 때 역유동층 생물막 반응기와 3상 유동층 생물막 반응기의 제거효율은 각각 94%, 92.5%였다. 유기물 부하율이 2㎏COD/㎥.day였을 때 역유동층 생물막 반응기의 미생물 농도는 2810㎎/L, 3상 유동층 생물막 반응기의 경우는 2300㎎/L 였다. 반응기 부피, 공기유량, media 형태 및 폐수성상이 모두 같은 조건에서는 두 반응기 모두 유기물 제거효율과 미생물 농도 등에서 거의 비슷한 거동을 나타내었다. A number of experiments were conducted to examine the COD removal efficency and the biomass concentration of the three phase fluidized bed biofilm reactor(TFR) and inverse fluidized bed biofilm reactor(IFR) using fibrous plastic ball and synthetic wastewater. When the influent SCOD was 1800㎎/L, SCOD removal efficiency of IFR and TFR were 94% and 92.5%, respectively. When organic loading rate was 2㎏COD/㎥.day, the biomass concentrations of the IFR and the TFR were 2810㎎/L and 2300㎎/L, respectively. When operated at the same conditions on reactor volume, air flow rate, media type and wastewater characteristic, two reactors showed a very similar performance.

Continuous Ethanol Production by Tower Fermentor

Kuen Hack Suh(서근학),Seung Koo Song(송승구),Jae Hyung Kim(김재형) 한국생물공학회 1994 KSBB Journal Vol.9 No.2

이중 불확실성하의 공정-저장조 망구조 최적설계

서근학(Kuen-Hack Suh),이경범(Gyeongbeom Yi) 제어로봇시스템학회 2010 제어·로봇·시스템학회 논문지 Vol.16 No.3

The aim of this study is to find an analytic solution to the problem of determining the optimal capacity of a batch-storage network to meet demand for finished products in a system undergoing joint random variations of operating time and batch material loss. The superstructure of the plant considered here consists of a network of serially and/or parallel interlinked batch processes and storage units. The production processes transform a set of feedstock materials into another set of products with constant conversion factors. The final product demand flow is susceptible to joint random variations in the cycle time and batch size. The production processes have also joint random variations in cycle time and product quantity. The spoiled materials are treated through regeneration or waste disposal processes. The objective function of the optimization is minimizing the total cost, which is composed of setup and inventory holding costs as well as the capital costs of constructing processes and storage units. A novel production and inventory analysis, the PSW (Periodic Square Wave) model, provides a judicious graphical method to find the upper and lower bounds of random flows. The advantage of this model is that it provides a set of simple analytic solutions while also maintaining a realistic description of the random material flows between processes and storage units; as a consequence of these analytic solutions, the computation burden is significantly reduced. The proposed method has the potential to rapidly provide very useful data on which to base investment decisions during the early plant design stage. It should be of particular use when these decisions must be made in a highly uncertain business environment.

수송공정을 고려한 다분기 공정-저장조 망구조의 최적설계

서근학(Kuen-Hack Suh),이경범(Gyeongbeom Yi) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.9

The optimal design of batch-storage network by using periodic square wave model provides analytical lot sizing equations for a complex supply chain network characterized as multi-supplier, multi-product, multi-stage, non-serial, multi-customer, cyclic system including recycling and/or remanufacturing. The network structure includes multiple currency flows as well as material flows. The processes are represented by multiple feedstock/product materials with fixed composition which are very suitable for production processes. In this study, transportation processes that carry multiple materials with unknown composition are added and the time frame is changed from single period into multiple periods in order to represent nonperiodic parameter variations. The objective function of the optimization involves minimizing the opportunity costs of annualized capital investments and currency/material inventories minus the benefit to stockholders in the numeraire currency. The expressions for the Kuhn-Tucker conditions of the optimization problem are reduced to a multiperiod subproblem for average flow rates and analytical lot-sizing equations. The multiperiod lot sizing equations are different from single period ones. The effects of corporate income taxes, interest rates and exchange rates are incorporated.

효모의 연속 포말 분리

서근학(Kuen Hack Suh),심현관(Hyun Kwan Shim),윤종원(Jong Won Yun) 한국생물공학회 1996 KSBB Journal Vol.11 No.1

해조류를 이용한 Pb 및 Cu의 흡착

서근학(Kuen-Hack Suh),안갑환(Kab Hwan Ahn),조문철(Moon-Chul Cho),김병진(Byong-Jin Kim),진형주(Hyung-Joo Jin),홍용기(Yong-Ki Hong) 한국생물공학회 1998 KSBB Journal Vol.13 No.4

재고부족 비용을 고려한 공정-저장조 망구조의 최적설계

서근학(Kuen-Hack Suh),이경범(Gyeongbeom Yi) 제어로봇시스템학회 2010 제어·로봇·시스템학회 논문지 Vol.16 No.5

This study deals with stockout costs in the supply chain optimization model under the framework of batch-storage network. Stockout is very popular in chemical industries. Estimating stockout cost involves an understanding of customer reactions to a seller being out of stock at the time the customer wants to buy an item. This involves massively non-trivial work such as direct customer interviews and extensive mail survey. In this study, we will introduce a new interpretation of stockout costs combined with batchstorage network optimization model and thus suggest an easy way of estimating stockout costs. Optimization model suggest that optimal process and storage sizes considering stockout cost are smaller than those that do not consider stockout cost. An illustrative example support the analytical results.

합성 양어장수 속의 NH3-N 제거 위한 질화세균 고정화된 생물반응기

서근학(Kuen Hack Suh),김용하(Yong Ha Kim),김병진(Byong Jin Kim) 한국화학공학회 1999 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.37 No.3

Nitrifier consortium entrapped in Ca-alginate bead was packed into packed bed bioreactor and the performance of bioreactor was evaluated for the removal of ammonia nitrogen from synthetic aquaculture water. Total ammonia nitrogen (TAN) removal rate by packed bed bioreactor was continuously increased with decreasing hydraulic residence time (HRT). The optimum ratio of packing height and inner diameter of reactor (H/D) was 4. TAN removal rate was increased proportionally with superficial liquid velocity. Low dissolved oxygen (DO) concentration was limiting factor for nitrification but DO concentration does not affect nitrification below 0.1 hour of HRT.