• 한국축산식품학회지
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• 제20권1호
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• pp.30-35
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• 2000

The method used to remove cholesterol from egg by using $beta$-cyclodextrin was relatively stable and efficient. The aim of this study was to cost down by recycling $\beta$-cyclodextrin used to remove cholesterol from egg yolk because $\beta$-cyclodextrin was expensive. The solvents used to separate $\beta$-cyclodextrin from $\beta$-cyclodextrin complex containing egg yolk cholesterol were butanol, chloroform, ether, hexane, methanol, 2-propanol and their mixture. The ratio of solvent and complex varied from 2 : 1 to 10 : 1. The condition of mixing time and temperature varied from 30 to 60$^{\circ}C$ and from 10 minutes to 3 hours to remove cholesterol from $\beta$-cyclodextrin complex. When the ratio of choloroform and methanol was 1 : 1, the removal efficiency of cholesterol was 98.8%. The efficiency of cholesterol removal was improved when the ratio of solvent : complex increased to 4 : 1. When mixing time and temperature was up to for 1hr, at 50$^{\circ}C$ respectively, the efficiency of cholesterol removal improved to 99%. It concluded that the efficiency of cholesterol removal of 50% renewed one contained $\beta$-cyclodextrin were 81.1% while the cholesterol removal efficiency of 100% renewed $\beta$-cyclodextrin was 24% if cholesterol removal efficiency of new $\beta$-cyclodextrin were 100%.

• 한국물환경학회지
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• 제22권1호
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• pp.122-127
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• 2006

Fundamental studies were carried out for an effective removal and recovery of silver from waste photo-developing solution by solvent extraction. The organic solvents examined for silver-extraction were ALIQUAT 336, D2EHPA, KELEX 100, and TBP. ALIQUAT 336, which is an anionic exchanger, was found to be efficient for the extraction of silver and the reason for this was considered to be due to the chloride ion contained in its structure. The extent of silver extraction was examined to increase with the concentration of ALIQUAT 336 until it reached 0.6 M and no more extraction was observed above this concentration. The extraction of silver by ALIQUAT 336 was found to reach its pseudo-equilibrium within a few minutes after the reaction started and additional slight increase in silver extraction was observed until 30 minutes of reaction time. The observed differences in silver extraction for artificial and actual waste solutions were considered to be based upon the different ionic form of silver-containing species in these solutions.

• Membrane and Water Treatment
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• 제8권1호
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• pp.19-34
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• 2017

Boron exists in dilute concentrations in sea water, ground water and waste waters. Reactive liquid extraction can be used for removing boron to make the treated water suitable for drinking and irrigation, with its final concentration less than 0.5 ppm. The results of equilibrium experiments are reported on the removal of boron using 2-butyl-2-ethyl-1, 3-propanediol (BEPD as a nonionic carrier) in sunflower oil, a non-traditional solvent. The results of removal of boron from aqueous solutions in the concentration range 0.5-20 ppm are presented. It is shown that this new liquid membrane system, is able to remove boron from ground waters at their natural pH of 6-8 (without any chemical addition for pH adjustments). The removal efficiency is good when the process is upgraded to a hollow-fibre membrane contactor and approximately 45% boron can be removed in a single-stage contact. There are additional advantages of this new approach that includes reduced operational health and safety and environmental issues. The results reported here provide guidelines to the development of boron removal process using renewable, biodegradable, safe and cheap solvent system such as sunflower oil.

• 공업화학
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• 제7권4호
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• pp.802-808
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• 1996

규산 나트륨으로부터 묽은 황산으로 산성화시킨 규산 나트륨용액으로부터 유기 용매에 의한 추출로 규산[Silicic Acid(SA)]을 제조하였다. 유기 용매로 tetrahydrofuran(THF), isopropyl alcohol과 acetone을 사용하여 Si 추출율과 Na 제거율에 미치는 영향과 유기 용매의 부피비, 염화 나트륨 첨가량 및 $H_2O$ 첨가량에 따른 영향을 파악하였다. 고순도 규산을 제조하기위한 최적 조건은 유기 용매 THF, 유기 용매/규산의 부피비 1(organic solvent 10ml/10ml SA) 그리고 염화 나트륨 첨가량 2.5g/10ml SA이었고, 이 조건에서 Si 추출율 86.2%, Na 제거율 99.95%인 99.96%의 고순도 규산을 제조하였다.

• Korean Chemical Engineering Research
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• 제56권1호
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• pp.14-23
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• 2018

The effect of dodecylbenzene sulfonic acid (DBSA) with different addition amount of DBSA ($M_{DBSA}$), temperatures and solvent-to-oil ratio (SOR, v/v) on asphaltene aggregation in a solvent deasphalting system was investigated. Increasing the $M_{DBSA}$ at SOR 10 and $55^{\circ}C$ caused the asphaltene removal ratio (ARR) to increase first, then maximize at 1 wt% of $M_{DBSA}$ and then decrease continuously. Based on the SARA (saturate, aromatic, resin, asphaltene) composition, the adsorption amount of DBSA on the asphaltene surface and the self-aggregation of the DBSA, the reason for the change in ARR with $M_{DBSA}$ was found due to the adsorption mechanism. In addition, the asphaltene-resin-DBSA colloidal size confirmed the change of adsorption behavior between the asphaltene and DBSA. Based on the results of this study, a hypothetical adsorption mechanism of DBSA on asphaltene aggregation in the solvent deasphalting system was conceived of and proposed.

• 보존과학회지
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• 제34권6호
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• pp.569-580
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• 2018

The possibility of applying poulticing was studied for removing Paraloid B72, a resin used for fixing an earthen mural painting. Five types of poultices were selected from clay and gel types, and acetone, ethanol, and methyl ethyl ketone(MEK) were used as mixed solvents. The possibility of mixing between the poultice and solvent was investigated, and then the spreadability, fluidity, acidity, drying properties, and solubility of the poultices were examined to confirm the characteristics. A poultice agent, which is suitable for applying to a mural painting, was selected and applied to a painting layer sample coated with Paraloid B72. As a result, all painting layers were good condition at under 50% of the solvent. The removal efficiency of Paraloid B72 was more effective when most of the solvents were used at 50%, rather than at 25%. However, it is difficult to mix 50% of MEK and ethanol with the gel-type poultices. When used at 25%, the removal performance was poorer than that at 50%, but the mixing with all the poultices was successful. In addition, the adsorption and removal power of the gel-type poultice were better than those of the clay-type, but the latter was expected to be more suitable in short-time cases due to its high drying speed. The results of this study show that the dissolution performance varies depending on the poultices and solvents. Hence, the poultice and solvent should be selectively applied, considering the fixative of the mural to be removed.

• Korean Chemical Engineering Research
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• 제60권2호
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• pp.237-242
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• 2022

본 연구에서는 정제된(+)-dihydromyricetin로부터 잔류 용매를 효과적으로 제거할 수 있는 건조 방법을 개발하였다. 에탄올 전 처리를 통한 회전 증발(rotary evaporation)에 의해 잔류 아세톤 농도를 ICH 규정치(5,000 ppm) 이하로 효율적으로 제거하였다. 또한 잔류 에탄올 역시 물 첨가를 통한 회전 증발로 ICH 규정치(5,000 ppm)를 충족시켰으며 잔류 수분 함량은 4% 이내였다. 모든 건조 온도(35, 45, 55 ℃)에서 잔류 용매는 건조 초기에 급격히 제거되었으며 건조 효율은 건조 온도가 높을수록 증가하였다. 건조 메커니즘 조사 결과, 에탄올 전 처리에 의한 잔류 용매 제거는 아세톤-에탄올 혼합물의 높은 증기압과 아세톤-에탄올 간의 수소 결합과 연관됨을 알 수 있었다.

• 신재생에너지
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• 제19권4호
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• pp.27-34
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• 2023

In this study, microalgal oil was extracted from Nannochloropsis oceanica cultured in an open raceway pond and converted into biodiesel using a solid acid catalyst. Microalgal oil was extracted from two types of microalgae with and without nitrogen starvation using the KOH-solvent extraction method and the fatty acid content and oil extraction yield from each microalgae were compared. The fatty acid content of N. oceanica was 184.8 mg/g cell under basic conditions, and the oil content increased to 340.1 mg/g under nitrogen starvation conditions. Oil extraction yields were 90.8 and 95.4% in the first extraction, and increased to 97.5 and 98.8% after the second extraction. Microalgal oil extracted by KOH-solvent extraction was yellow in color and had reduced viscosity due to chlorophyll removal. In biodiesel conversion using the catalyst SO₄^2-/HZSM-5, solvent-extracted oil showed a FAME content of 4.8%, while KOH-solvent-extracted oil showed a FAME content of 90.4%. Solid acid catalyst application has been made easier by removal of chlorophyll from microalgal oil. The FAME content increased to 96.6% upon distillation, and the oxidation stability increased to 11.07 h with addition of rapeseed biodiesel and 1,000 ppm butylated hydroxyanisole.

• Asian-Australasian Journal of Animal Sciences
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• 제14권4호
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• pp.548-552
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• 2001

This study was designed to find optimum conditions of four different factors (ratio of solvent to cholesterol-$\beta$-cyclodextrin complex, mixing speed, mixing temperature, and mixing time) for cholesterol dissociation in cream. Using the ratio of 6 to 1 (solvent to the complex) showed the highest cholesterol dissociation rate (82.50%) when mixed at 100 rpm at $50^{\circ}C$ for 1 h. Mixing speed did not significantly affect the cholesterol dissociation. Also, mixing time appeared to be insignificant. The optimum mixing temperature was $50^{\circ}C$ and mixing at $40^{\circ}C$ resulted in a significantly lower rate, compared with that at $50^{\circ}C$. In a subsequent experiment, using recycled $\beta$-cyclodextrin only showed 75.07% of cholesterol removal in cream, while the mixture of recycled to unused $\beta$-CD with the ratio of 6 to 4 increased cholesterol removal to 95.59%, which is highly close to that of 100% unused $\beta$-CD.

• 접착 및 계면
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• 제24권1호
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• pp.17-25
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• 2023

본 연구는 투명 폐 Polyethylene Terephthalate (PET)병을 재활용하여 지지체를 제조 후에 Polyetherimide (PEI)를 이용하여 친환경적인 유기용매나노여과막 (Organic Solvent Nanofiltration)에 이용하고자 하였다. 제조된 복합막은 먼저, PET 지지체는 전기방사를 통해 제조를 하였으며 이후 내용매성이 우수한 PEI를 이용하여 지지체 위에 캐스팅하였고 비용매 유도상분리(Non-solvent Induced Phase Separation, NIPS) 방법을 이용하여 유기용매나노여과막을 제조하였다. 먼저 막제조에 앞서 제조된 PET 지지체는 모폴로지 분석을 통해 섬유의 직경과 인장강도를 파악하였으며 유기용매나노여과막의 최적 지지체 조건을 확인하였다. 이후 제조된 PET/PEI 복합막은 PEI의 농도에 따른 유기용매나노여과막으로서의 성능을 파악하기 위하여 에탄올에 분자량 697 g/mol을 가지는 Congo red의 제거율을 확인하였으며 최종으로 Congo red의 제거율이 90%이상의 제거율을 가지는 최적의 PET/PEI 복합막을 확인하였다.