• 동의생리병리학회지
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• 제26권1호
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• pp.35-39
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• 2012

Sweet potato soju(SPS) has been made by vacuum distillation because sweet potato contains much fibrous materials which give high density to sweet potato mash. Generally, the SPS made by vacuum distillation has soft flavors and tastes. If the viscosity of sweet potato mash could be decreased by degradation enzyme, the process and production of SPS making by the method of vacuum distillation may be simplified and easier to distil the fermented sweet potato. Because the fibrous materials of sweet potato contains pectin with methoxyl group, methanol can be produced by fibrous degradation enzyme. For appling the fiber degradation enzymes to sweet potato mash for making SPS, the enzyme should be needed to degrade fibrous material without producing methanol. Special two fibrolytic enzymes are selected from 26 kind of commercial enzymes for the simplified and easier production of sweet potato soju by vacuum distillation, The selected enzyme A and X can degrade the fibrous material pectin of sweet potato without producing methanol. Although the different companies have produced the enzymes, same cellulase has been prepared from Trichoderma. reesei. The viscosity of sweet potato mash treated by the enzymes is decreased by 3 times with comparison to the viscosity of sweet potato mash of control group. The methanol concentration in the vacuum distilled SPS treated with the enzymes is 0.16%. The concentration is similar to that of commercially distilled SPS(0.15%). The result may suggest that the selected cellulases, A and X, can be used to make SPS by vacuum distillation.

• 한국유체기계학회 논문집
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• 제16권1호
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• pp.56-60
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• 2013

Non-conventional oil resources such as shale gas are becoming increasingly important and have drawn the attention of several major oil companies all over the world. Nevertheless, the market-changing growth of shale gas production in recent years has resulted in the emergence of environmental and water management challenges. This is because the water used in the hydraulic fracturing process contains large amount of pollutants including ions, organics, and particles. Accordingly, the treatment of this flowback water from shale gas plant is regarded as one of the key technologies. In this study, we examined the feasibility of membrane distillation as a treatment technology for the water from shale gas plants. Direct contact membrane distillation (DCMD) is a thermally-driven process based on a vaper pressure gradient across a hydrophobic membrane, allowing the treatment of feed waters containing high concentration of ions. Experiments were carried out put in the lab-scale under various conditions such as membrane types, temperature difference, flow rate and so on. Synthetic feed water was prepared and used based on the data from literature. The results indicated that DCMD is suitable for treating not only low-range flowback water but also high-range flowback water. Based on the theoretical calculation, DCMD could have over 80% of recovery. Nevertheless, organic pollutants such as oil and surfactant were identified as serious barriers for the application of MD. Further works will be required to develop the optimum pretreatment for this MD process.

• 상하수도학회지
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• 제31권3호
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• pp.229-236
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• 2017

In this study, a direct contact membrane module was manufactured to be used in a pilot scale membrane distillation process to treat $3m^3/day$ of the digestate produced from anaerobic digestion of livestock manure. In order to investigate the performance of the membrane module, permeate flux was measured with and without spacer inside the module under various condition of temperature difference and cross flow velocity (CFV) through the membrane surfaces. Flux recovery rate after chemical cleaning was also investigated by applying three different cleaning methods. Additionally, thermal energy consumption was theoretically simulated based on actual pilot plant operation conditions. As results, we observed flux of the module with spacer was almost similar to the theoretically predicted value because the installation of spacer reduced the channeling effect inside the module. Under the same operating condition, the permeate flux also increased with increasing temperature difference and CFV. As a result of chemical in-line cleaning using NaOCl and citric acid for the fouled membranes, the recovery rate was 83.7% compared to the initial flux when NaOCl was used alone, and 87% recovery rate was observed when only citric acid was used. However, in the case of using only citric acid, the permeate flux was decreased at a rapid rate. It seemed that a cleaning by NaOCl was more effective to recover the flux of membrane contaminated by the organic matter as compared to a cleaning by citric acid. The total heat energy consumption increased with increasing CFV and temperature difference across the membrane. Thus, further studies should be intensively conducted to obtain a high permeate flux while keeping the energy consumption to a minimum for a practical application of membrane distillation process to treat wastewater.

• 한국초전도ㆍ저온공학회논문지
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• 제3권1호
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• pp.69-73
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• 2001

For developing the cryogenic air separation unit, it requires some technology such as basic process design. equipment design and manufacturing based on the cryogenic physical properties and separation theory. In this study, we developed a process and equipment for producing high purity nitrogen which has the production capacity of 1600N㎥/h under 1 ppm $O_2$ and $H_2O$. Also we found that the number of theoretical plate(NTP) of distillation column was 44 and maximum nitrogen recovery ration of this process was 42% from the process simulation. The performance test was also carried out for the nitrogen recovery ratio and equipment efficiency. The results showed that the optimum nitrogen recovery was 41% and the maximum equipment efficiency was attained.

• 대한기계학회논문집B
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• 제33권5호
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• pp.373-380
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• 2009

The evaporation process of multi-component fuel is different from one of a single component, because the properties of each component affects among the components. In actual engine, the spatial distribution of fuel vapor concentration dominates auto-ignition and initial combustion, and depends on the volatility and diffusivity of each component fuel contained in the multi-component fuel. Then, this study proposes a simplified numerical scheme for analysis of evaporation process of multi-component fuel sprays. Evaporation process is calculated by KIVA-II code based on the simple two-phases region that is approximated by modified saturated liquid-vapor line, which was obtained by connecting the 50% distillation temperature for each component under several pressure fields. Consequently, it can be quantitatively simulated that vapor of low boiling fuel component mostly exists around nozzle and spray tip region, the high boiling duel component, on the other hand, mostly appears near the spray tip.

• Korean Chemical Engineering Research
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• 제58권4호
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• pp.565-572
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• 2020

본 연구는 증류탑 분리공정 시스템 최적화를 위하여 인공지능 머신러닝이 적용된 소프트웨어 플랫폼을 개발하였다. 증류탑 분리공정은 석유화학 산업의 대표적이고 핵심적인 공정이다. 하지만 다양한 운전조건과 연속식공정 특성으로 인하여 안정적인 운전이 어려우며 운전자 숙련도에 의하여 공정효율에 차이가 발생된다. 이를 해결하기 위하여 이론적 시뮬레이션을 활용한 제어방법이 개발되어 사용되고 있지만 특수하거나 복잡한 반응이 포함된 공정에는 적용이 어려우며, 거대한 시스템에 대하여 분석이 이루어질 경우 계산비용 증대로 인하여 실시간 제어와 연동이 어려운 한계점을 지니고 있다. 따라서 본 연구에서는 이러한 문제점을 해결하기 위하여 머신러닝을 기반으로 한 경험적 시뮬레이션 모델을 개발하고 이를 통하여 최적의 공정운영방법을 제시하고자 한다. 경험적 시뮬레이션 개발은 실제 공정에서 수집된 빅 데이터, 데이터마이닝을 통한 특성추출, 공정을 대표하는 데이터 선별, 화학공정 특성에 맞는 모델 선정으로 이루어졌으며, 현장검증 및 테스트를 통하여 증류탑 분리공정 플랫폼이 개발되었다. 최종적으로 개발된 플랫폼을 통하여 운전 조작변수의 예측이 가능하며, 최적화된 운전조건을 제공하여 효율적인 공정운영을 달성할 수 있다. 본 논문은 머신러닝 기법을 화학공정에 적용한 기초연구로서 이후 다양한 공정에 적용하여 4차 산업의 스마트 팩토리의 초석이 되어 널리 활용될 수 있을 것이라 판단된다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2003년도 추계 학술발표회 논문집
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• pp.149-152
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• 2003

• 청정기술
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• 제14권2호
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• pp.129-135
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• 2008

이축연신 나이론 막을 사용한 단일투과증발막 셀을 이용하여 공급액의 온도 및 농도에 따른 투과실험식을 구하고, 투과증발막 모듈을 사용하여 이 실험식의 적합성 및 투과시 소요되는 소비에너지를 산출하였다. 투과증발막 모듈을 이용해서 투과측의 압력이 2 mmHg와 20 mmHg의 경우 공급액의 에탄올 농도 90 wt%를 99.5 wt%로 농축시키는 경우, 투과측압력이 2 mmHg일 때가 20 mmHg일 때에 비해 동일조건의 에탄올 농축을 위한 막의 면적이 증가하였다. 각 압력의 조건에서 나이론 막을 이용한 membrane-aided distillation의 모사를 한 막의 투과속도 및 선택성에 대한 실험식을 도출하고 이를 이용하여 10 wt%의 에탄올 수용액을 99.5 wt%로 농축하는 membrane-aided distillation공정의 소비에너지를 구하였다. 그 결과 막의 투과량이 과다한 경우 다시 증류탑에서 재 농축을 해야하므로 막에 의한 에너지소비 절감효과가 상쇄될 수 있음을 보여주었다. 따라서 이 공정에 의해 에탄올을 농축하는 경우 효과적으로 에너지를 절약하기 위해서는 막의 선택성이 매우 중요하다는 것을 보여주었다.

• 기술사
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• 제18권2호
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• pp.6-15
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• 1985

A new process disregraded the H$_2$SO$_4$ treatment process heretofore in use, was developed and substituted for mineral base engine used oil of homemade SAE-30 grade H.V.I., which was used covering 4,500km, as samples, and the following results in research, was obtained. (1) A good quality of rerefinded base oil was obtained through roughly a course of developed processes of vacuum distillation process, solvent extraction process, neutralization treatment process and clay treatment process. (2) Through vacuum distillation process, the size of fine grains of insoluble colloid carbon that is, colloid carbon which was produced by burning of internal combustion engine oil and fuel, could be brought up and precipitated (3) The insoluble matters and admixtures could be easily dispersed and dissolved by mixing and extracting solvent disregarded the H$_2$SO$_4$ treatment process heretofore in use (4) waste matter heretofore called acid sludge in consequence of the process, did not appear at all. accordingly, the environmental pollution could be removed. (5) The troubles of corrosion to copper strip which was faults of the usual used oil refined products and peculiar offensive odor of the rerefined oil, could be solved through the neutralization process. (6) The yield of rerefined oil obtained through a course of processes was over 86 percent, and it is of practical use, not to speak of commercial value.

• Korean Chemical Engineering Research
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• 제46권4호
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• pp.739-746
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• 2008

반응증류 공정은 전형적인 반응공정과 증류공정을 통합하여 증류탑에서 반응과 동시에 분리를 수행하는 공정이다. 반응증류 공정의 가장 큰 장점은 반응 전환율의 제약과 공비점으로 인한 제약을 효율적으로 극복할 수 있다는 데 있다. 본 연구에서는 에스테르화반응으로 얻어지는 대표적인 물질인 메틸 아세테이트를 합성, 생산하는 연속 반응증류 공정의 상세한 수학적 모델을 구성하여 동적 모사 및 동적 최적화를 수행하였다. 상평형을 가정한 평형단 모델에 반응속도 식을 적용하여 분리와 반응이 함께 일어나는 증류탑과 재비기 및 응축기를 수학적 모델로 구성하여 동적모사를 수행하여 실제 공정이 운전되는 시나리오대로 공정전체를 모사함으로써 공정 개시부터의 공정의 동적 특성을 살펴보았다. 이 동적 모델과 연계되어, 반응증류 공정으로 얻어지는 메틸 아세테이트의 순도를 목적함수로 하는 최적화 문제를 구성하여 그 결과로 최적의 원료주입 분율 및 재비기의 열량 및 환류비 등을 구할 수 있었다. 또한 여기서 얻어진 운전 변수의 값을 변화시킬 때 반응 전환율의 변화를 살펴봄으로써, 최적화 문제의 해로 구해진 운전 변수의 값의 타당성을 증명하였다.