• 대한기계학회논문집B
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• 제38권2호
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• pp.165-172
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• 2014

단일 노즐을 이용하는 $CO_2$ 포집용 분무탑의 기본적 특성을 실험적으로 구하였다. 다양한 조건 - 주입 기체 유량 및 농도, 주입 흡수제 유량 및 농도 등 - 에서 얻어진 포집성능을 포집효율 뿐만 아니라 재생에너지의 주요 결정요인인 $CO_2$ 포화도 측면에서 검토하였다. 다양한 조건들에서의 포집효율 변화는 흡수제($NH_3$)와 $CO_2$의 상대적 유량비만의 단조증가함수로 잘 표현되었다. 포집후의 흡수제의 $CO_2$ 포화도 또한 $NH_3/CO_2$ 유량비만의 함수로 잘 정리가 되었으나, 포집효율과는 다르게 단조감소함수를 보였으며, 특히 $CO_2$ 포화도와 포집효율과의 상관관계를 보면 기존의 모든 연구들에서 포집효율이 증가할수록 $CO_2$ 포화도가 감소하였다. $CO_2$ 포화도는 낮은 포집효율 조건에서 최대 20-25% 수준이었으나, 90% 이상의 고효율에서는 10% 미만으로 매우 낮았다. 이는 높은 포집효율을 위해 사용되는 흡수제의 양이 과도하며, 다시 재생에너지가 과도하게 필요함을 의미한다.

• 한국수소및신에너지학회논문집
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• 제28권4호
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• pp.361-368
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• 2017

Alanate-based materials, which were known to have high hydrogen storage capacity, were synthesized by mechanochemically metathesis reaction of metal chloride and sodium alanate without solvent. XRD patterns of synthesized materials showed that metathesis reaction of cations between metal chloride and sodium alanate was progressed favorably without any solvent. Magnesium alanate showed that 3.2 wt.% of hydrogen was evolved by the thermal decomposition. The addition of a small amount of Ti to the magnesium alanate greatly reduced hydrogen evolution temperature. Also, Ti doped magnesium alanate had a good regeneration property. Both the calcium and lithium-magnesium alanate showed the lower starting temperature of the two step hydrogen evolution and fast kinetics for the hydrogen evolution.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권6호
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• pp.386-394
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• 2001

Carboxylic acids are examples of compounds with wide industrial applications and high potential, This article presents the principles of reactive extraction along with the character-istics of tertiary amine extractants, while is given on considering the effect of the amine class and chain length, As such a brief overview the current research on reactive extraction, including the recovery of citric acid, selective amine-based extraction , and extractive fermentation is given. When discussing extractive fermentation strategies for reducing solvent toxicity are also suggested based on specific examples. Finally, solvent regeneration and stripping of extracted acid explained.

• 청정기술
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• 제23권4호
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• pp.393-400
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• 2017

본 연구에서는 염화제이철의 재생공정으로 기존 용매추출법에서 사용하고 있는 용매인 TBP 및 Alamine336 대신에 새로운 용매를 통해 용액 내에 존재하는 Ni과 Fe를 분리 및 회수하는 공정을 개발하였다. Lab 실험을 통하여 실험조건을 최적화하였으며, 이를 바탕으로 상업화를 위한 $10L\;h^{-1}$급 파일럿 설비를 구축하였다. 또한 파일럿 실험을 통하여 양산을 위한 공정 데이터를 확보하였으며, 제조된 염화제이철의 부식실험을 통하여 사용할 수 있는 제품 품질에 문제없음을 확인하였다.

• 한국가스학회지
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• 제20권1호
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• pp.1-6
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• 2016

기후변화의 가장 큰 원인 중 하나로 지목되는 이산화탄소의 배출량을 절감하기 위해 제안된 Carbon Capture and Storage (CCS) 전체공정의 에너지 및 비용저감이 시급한 현 시점에서 효율적인 연계공정의 도출이 중요하며 본 연구에서는 연소 후 습식아민 공정을 이용한 포집공정과 압축공정의 간의 연계를 통해 에너지를 저감할 수 있는 방법을 제안한다. 이는 기기적 증기 재압축 시스템 을 적용하여 압축기에 사용되는 전기에너지를 열에너지의 형태로 변환함으로써 포집공정에 필요한 리보일러의 에너지 사용량을 감소시키는 방법이다. 본 공정개선안은 압축기에 필요한 추가적인 투자비용 및 전기에너지를 고려하더라도 고압의 이산화탄소를 생산함과 동시에 전체적인 에너지 사용량을 절감시키는 장점이 있다. 또한 본 연구에서는 실제 Test Bed의 운전 결과를 통한 모델을 활용함으로써 보다 신뢰성 있는 절감 효과를 제안하고자 한다.

• 폴리머
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• 제39권1호
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• pp.40-45
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• 2015

혈항혈전성 표면의 제조를 위해 간단한 비용매 휘발 방법을 통하여 고탄성체이면서 생분해성 폴리 락티드-카프로락톤 공중합체 필름의 표면상에 연잎 구조물과 유사한 마이크로 돌기를 만들어 주었다. 표면 구조와 소수성도, 항혈전 효과 등을 시험했으며, 결정화도와 탄성회복률 등의 물리적 특성도 분석하였다. 그 결과 비용매와 메틸렌클로라이드의 혼합 부피비 1:2에서 연잎표면과 유사한 최적의 효과를 얻었으며, 이때 수접촉각은 $124^{\circ}$였다. 혈소판 부착시험에서는 처리하지 않는 군에 비해 약 10%만 부착되는 효과를 확인할 수 있었다.

• 한국기계가공학회지
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• 제13권3호
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• pp.35-41
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• 2014

Poly(g-glutamic acid) (g-PGA) is a very promising biodegradable polymer that is produced by microorganism of Bacillus subtilis. Because g-PGA is water-soluble, anionic, biodegradable, and even edible, its potential applications have been studied from an industrial standpoint. In this study, we fabricated porous g-PGA foams by means of a freeze-solvent extraction method for tissue-engineering applications. Porous g-PGA foams were chemically cross-linked using a hexamethylene diisocyanate solution. An aqueous basic solution was used to neutralize g-PGA foam for cell culturing. During an in vitro cell culture study, it was observed that primary rabbit ear chondrocytes were well at tached and spread over the surface oft hree-dimensional cross-linkedg-PGA foam. From these results, it is concluded that cross-linkedg-PGA foam is aprom is in gmaterial for tissue-engineering applications, especially those pertaining to the regeneration of human cartilage.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2004년도 춘계임시총회 및 제23회 학술대회
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• pp.218-226
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• 2004

Solvent extraction and stripping experiments were conducted to separate iron from a spent $FeCl_3$ etching solution containing nickel. In the extraction, PC88A, MIBK and Alamine336 were tested as an extractant in various diluents. Alamine336 salt in toluene led to the highest extraction percentage of iron. Stripping percentage of iron from the loaded organic by Alamine336 increased with decreasing HCl conentration of stripping solution and with increasing volume ratio of aqueous to organic. In the operation of bench scale mixer-settler, 7 extraction stage with 1.0M Alamine336 salt in toluene and 10 stripping stage with 0.01M HCl solution resulted in a stripped solution with 133g/L of iron and in a raffinate with most of nickel together with a small amount of iron when the flow rate ratio of organic to aqueous was 7.

• 펄프종이기술
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• 제47권6호
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• pp.113-122
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• 2015

This study was carried out to investigate the characterization of cadmium adsorption by cellulose hydrogel and aerogel. Hydrogel and aerogel were made from ashless pulp dissolved in alkali hydroxide-urea aqueous solution and manufactured in film and bead types. After regeneration of cellulose, hydrogel went through the process of substitution of organic solvent and freeze-dry in order to make aerogel. SEM was used to analyze the microstructure of hydrogel and aerogel. Experiment was conducted in various concentrations and pH conditions to find out the characteristic of cadmium adsorption. After that, EDS was used to identify existence and distribution of cadmium in hydrogel and aerogel. The result from comparisons of cadmium adsorption shows that bead type aerogel has the maximum cadmium adsorption and film type hydrogel has the minimum cadmium adsorption.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권4호
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• pp.323-332
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• 2008

Aim of the study: Scaffolds are crucial to tissue engineering/regeneration. Biodegradable polymer/ceramic composite scaffolds can overcome the limitations of conventional ceramic bone substitutes such as brittleness and difficulty in shaping. In this study, poly(L-lactide)/hydroxyapatite(PLLA/HA) composite scaffolds were fabricated for in vivo bone tissue engineering. Material & methods: In this study, PLLA/HA composite microspheres were prepared by double emulsion-solvent evaporation method, and were evaluated in vivo bone tissue engineering. Bone marrow mesenchymal stem cell from rat iliac crest was differentiated to osteoblast by adding osteogenic medium, and was mixed with PLLA/HA composite scaffold in fibrin gel and was injected immediately into rat cranial bone critical size defect(CSD:8mm in diameter). At 1. 2, 4, 8 weeks after implantation, histological analysis by H-E staining, histomorphometric analysis and radiolographic analysis were done. Results: BMP-2 loaded PLLA/HA composite scaffolds in fibrin gel delivered with osteoblasts differentiated from bone marrow mesenchymal stem cells showed rapid and much more bone regeneration in rat cranial bone defects than control group. Conclusion: This results suggest the feasibility and usefulness of this type of scaffold in bone tissue engineering.