폐콘크리트를 이용한 산성광산배수의 중화 및 CO2 광물화

김우람,민경원,이현철 한국자원공학회 2018 한국자원공학회지 Vol.55 No.1

The present paper deals with applicability of waste concretes for neutralization of acid mine drainage (AMD) and mineralization of carbon dioxide (CO2). Ground waste concrete powders of under 75 µm were added to artificial mine drainage of 500 mL, until their pH reached about 11. When the pH of each solution was stabilized through continuous agitation, CO2 gas was injected with various flow rates until the pH decreased to 8.3. After termination of CO2 injection, the pH of the solutions decreased to the range of 6.3 to 8.2, furthermore, both pH and metal concentrations of the treated solutions were tolerable in terms of the effluent standard. In this experimental study of the AMD neutralization-carbonation using waste concretes, it was confirmed that AMD neutralization, metal control and CO2 mineralization can be conducted by waste concretes. It is also known that the efficiency of CO2 immobilization through neutralization-carbonation of acid mine drainage is dependent on waste concrete inputs which is controlled by the AMD property. 본 연구에서는 산성광산배수의 중화제로 폐콘크리트 미분말의 적용성을 알아보고 동시에 CO2 광물화의 가 능성을 고찰하였다. 폐콘크리트는 파·분쇄 후 체가름을 통한 75 µm 이하의 미분말을 인공광산배수 500 mL에 첨가하 여 pH가 11 정도가 되어 탄산화가 원활히 진행되도록 하였다. 지속적인 교반을 통해 pH를 안정화 시킨 후 다양한 주입 속도로 pH 8.3에 이를 때까지 CO2를 주입하였다. CO2 주입 종료 후 용액의 pH는 6.3∼8.2 범위 내에서 안정화되었으 며, pH와 금속이온 농도 모두 수질오염물질 배출허용기준에 적합한 것으로 나타났다. 본 연구에서 폐콘크리트 미분 말을 이용한 산성광산배수(AMD)의 중화-탄산화 실험을 통해 폐콘크리트를 이용하여 AMD의 중화 및 중금속 제어 과 함께 CO2를 효율적으로 광물화할 수 있음을 실험적으로 확인하였다. 또한 광산배수의 특성에 의해 중화-탄산화를 위한 폐콘크리트의 투입량이 조절되며, 이에 따라 CO2 고정화 효율에 영향을 주는 것으로 판단된다.

Preparation and characterization of ADN based monopropellant

김우람,권윤자,조영민 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

A newly popular solid oxidizer ADN [ammonium dinitramide, NH4N(NO2)2] was synthesized from direct nutralization of sulfuric acid/nitric acid and potassium sulfamate. A liquid monopropellant composed of ADN and other addtives including simple molecular fuel was then prepared and characterized focusing on thermal properties. The monopropellant for an attitude control thruster of satellite projectiles should achieve high performance in exothermic decomposition or combustion reactions in the absence of external oxygen. This work utilized pure water for main solvent, which is safe in handling and easy in controlling the catalytic decomposition. The obtained basic properties of the test sample were 1.25~1.40 g/㎤ for true density, below 170℃ for decomposition temperature, and -30℃ for frozen point. The calorimetric values of the monopropellant was 466.73 J/g.

실내공간 포름알데하이드 포집을 위한 목질계 활성탄흡착제 제조연구

김우람,허수정,조영민 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.0

Preparation and characterization of ADN based environmentally friendly mono-propellants

김우람,권윤자,정동원,조영민 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Hydrazine [N₂H₄] is a widely used mono-propellant for spacecraft thrusters. The toxicity and handling problems, however, limit its utilization in the other fields. A newly popular solid oxidizer ADN [ammonium dinitramide, NH₄N(NO₂)₂] was synthesized from direct neutralization of sulfuric acid/nitric acid and potassium sulfamate. A mono-propellant composed of ADN and other additives including simple molecular fuel was then prepared and characterized focusing on thermal properties. The mono-propellant for an attitude control thruster of satellite projectiles should achieve high performance in exothermic decomposition or combustion reactions in the absence of external oxygen. This work utilized pure water for main solvent, which is safe in handling and easy in controlling the catalytic decomposition. The obtained basic properties of the test sample were 1.25~1.40 g/㎤ for true density, below 170°C for decomposition temperature, and -30°C for freezing point.

탈질/탈황 폐 세정액으로부터 질산염 추출 및 정제 연구

김우람,조영민,이헌석,오수관,Kim, Woo-Ram,Jo, Young-Min,Lee, Heon-Seok,Oh, Soo-Kwan 한국응용과학기술학회 2015 한국응용과학기술학회지 Vol.32 No.1

전 세계적으로 증가하고 있는 선박 배출가스 규제를 위해 국제해사기구(IMO)는 배출되고 있는 가스의 부정적 환경영향에 대한 부각과 함께 법적인 규제를 강화하고 있다. 국제해사기구(IMO) 규제에 따라, 발트 해 연안을 지나는 모든 배들은 배출가스 제거창치를 장착해야 한다. 다양한 최신 탈황/탈질 장치가 소개되고 있는 가운데, 선박의 제한 된 공간을 활용한 폐 세정액 회수 공정 또한 중요한 기술로 발전 가능하다. 탈황/탈질 장치 후단에서 발생되는 폐 세정액은 질산암모늄, 황산암모늄과 같은 유용부산물을 포함하고 있다. 본 연구는 선택적 유기용매 염석 법, 저온 결정화 추출, 열 감압농축을 이용하여 유용부산물로서 질산암모늄을 추출하였다. 열 감압농축으로 얻어진 부산물을 반복적 유기용매 추출방법으로 정제했을 시 가장 높은 순도의 질산암모늄이 추출 되었다. 분석 장비를 통해 추출 된 유용 부산물의 성분 및 특성을 평가하였다. IMO to issue some restricted maritime legislation for reducing the adverse environmental impacts arising from such ship exhaust emissions. According to the IMO policy, every ship entering the Baltic SECAs has to equip the gas cleaning scrubber. The discharged waste solution by gas cleaning scrubber contains many types of salts, which to recover some valuable materials before disposal. This study try to achieve valuable salts including AN and AS throughout a few process such as selective organic solvents salting out, low temperature extraction and thermal evaporation. Amongst them, Thermal evaporation with repetition extraction using inorganic solvent was the most optimum to purify the extracted AN. This valuable salt was evaluated by Elemental analysis and Differential scanning calorimetry.

2P-429 고에너지 친환경 액상 추진제 조성연구

김우람,박연수,권윤자,조영민 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

2P-609 합성물 분리기술을 통한 AND 순도 및 수율 향상연구

김우람,조영민,권윤자,박영철 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.0

Preparation of liquid propellants by dinitramide based oxidizers

김우람,조영민 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

인공위성 자세 제어용으로서 적합한 비추력과 밀도 비추력을 갖춘 액상추진제를 고에너지산화제인 ADN[ammonium dinitramide], GDN[guanidine dinitramide], Py-DN[pyridinium dinitramide] 을 기반으로 각각 시험제조하였다. 추진제는 연료와 산화제, 용매와 상안정제 등을 혼합하여 제조하였고, 상안정성(DSC, freezing point), 밀도(ρ) 및 비추력(Isp)을 관찰하였다. 주 연료는 메탄올을 적용하되 에탄올과 혼합하여 발열량을 조절하였으며, 용매 내에서의 분산을 돕기 위하여 수산화아민을 비롯한 유기첨가물을 여러가지 비율로 첨가해보았다. 각 시료의 열분해 온도는 산화제 종류에 따라 168°C에서 182°C로 분포하였고, ADN 기반의 KHU-22 시료가 가장 높은 열분해 온도를 보여줌으로써 열안정성이 상대적으로 우수하다고 판단할 수 있었다. 각 시료의 비추력은 210 - 240 sec 로 나타났는 바, 기존의 상용 제품과 유사한 성능을 보유하고 있는 것으로 평가되었다. 한편, guanidine carbonate와 pyridine hydrochloride를 모체로 두 개의 질산기를 결합시킨 GDN과 Py-DN은 보조 추진제로서 액체연료의 발열량을 제어할 수 있는 조합으로의 개발여지가 충분하다.

Synthesis and characterization of a new energy material (guanidinium dinitramide) with crystallization solvent

김우람,박미정,박연수,권윤자,조영민 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.68 No.-

An environmentally favorable (chlorine-free) solid oxidizer, guanidinium dinitramide [GDN; NH2C(NH2)NH2N(NO2)2], was newly synthesized from guanidine carbonate [NH2C(NH)NH2·1/2H2CO3]. Two different crystalline forms (α-type and β-type) appeared according to the applied solvents and synthesis conditions. Moisture, during extraction, might become trapped in a crystal between inner molecules. Therefore, despite having the same chemical composition, Raman-IR and TGA-DSC revealed different physical characteristics of the two forms. Peaks of Raman shift near 1000 cm−1 implied different chemical structures. Thermal analysis revealed an exothermic temperature 155.7 °C for α-type but one of 191.6 °C for β-type. The caloric value of α-type was 536.4 J/g, which was 2.5 times larger than that of the β-type, which was 1310 J/g. While the synthesized GDN of α-type showed a steep exothermic decomposition, the β-type was slowly decomposed after melting through an endothermic process. This work implied that despite of the same molecular formula some different core thermal properties would appear depending on synthesis conditions.

Synthesis and characterization of a new energy material: Pyridinium dinitramide (Py-DN)

김우람,권윤자,Adedeji A. Adelodun,조영민 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-

A solid oxidizer pyridinium dinitramide (Py-DN) has been newly synthesized as a low toxic chlorine-free energetic oxidizer. The reaction yield increased by 10% higher than the other dinitramide such as ADN because Py-DN was directly converted without sequential precipitation of intermediates. A thermal analyzer, a UV–visible spectrometer and a Fourier transform-infra-red spectrometer were used to characterize the physical and chemical properties of the synthesized Py-DN, and the results were compared with previously prepared salts of ammonium dinitramide (ADN, NH4N(NO2)2) and guanidine dinitramide [GDN, NH2C(NH2)NH2N(NO2)2]. The characteristic endothermic and exothermic decomposition temperatures of Py-DN were 77.4 C and 144.7 C, respectively, and the material had a combustion caloric value of 1,739 J/g. These low values indicate that Py-DN is more thermally sensitive than the conventional dinitramides. Furthermore, it enables to decrease the decomposition temperature, which can reduce preheating temperature required for thruster operation.