• 제목/요약/키워드: alkane

검색결과 167건 처리시간 0.028초

여러 종류의 할로겐 화합물과 고분자량 파라핀계 탄화수소의 염소화에서 생기는 이성질화에 관한 연구 (Isomer Formation in the Chlorination of Highmolecular Paraffinic Hydrocarbons by Various Halogenating Agents)

  • 궁이환
    • 대한화학회지
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    • 제32권4호
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    • pp.390-405
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    • 1988
  • n-Heptane, n-Octane, n-Decane, 2,3-Dimethyl Butane을 chlorination agent인 N-chlorosuccinimide, tert-Butylhypochloride, Trichloromethanesulfonylchloride, Carbontetrachloride, Trichloromethanesulfenyl chloride, Phosphorous pentachloride Chlorine등으로 benzene 또는 $CS_2$ 용매중에서 염소화시킬때 생기는 Mono-chloro alkane의 이성질화 혼합물을 정량적으로 고찰하였다. 여기에서 파라핀계 탄화수소의 치환비율에 대한 지금까지 알려진 사실과 일치하지 않는 놀라운 이성질화 분포(Isomerization distribution)를 확립하였다. 이러한 결과는 극성효과를 갖는 공격하는 라디칼의 free energy, 그리고 alkane의 개개의 수소 원자가 지니는 여러가지 서로다른 C-H bond 해리에너지의 상호작용을 통하여 얻어졌다.

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Dye removal from water using emulsion liquid membrane: Effect of alkane solvents on efficiency

  • Ghaemi, Negin;Darabi, Farzaneh;Falsafi, Monireh
    • Membrane and Water Treatment
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    • 제10권5호
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    • pp.361-372
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    • 2019
  • Effect of different alkane based solvents on the stability of emulsion liquid membrane was investigated using normal alkanes (n-hexane, n-heptane, n-octane and n-decane) under various operating parameters of surfactant concentration, emulsification time, internal phase concentration, volume ratio of internal phase to organic phase, volume ratio of emulsion phase to external phase and stirring speed. Results of stability revealed that emulsion liquid membrane containing n-octane as solvent and span-80 (5 % (w/w)) as emulsifying agent presented the highest amount of emulsion stability (the lowest breakage) compared with other solvents; however, operating parameters (surfactant concentration (5% (w/w)), emulsification time (6 min), internal phase concentration (0.05 M), volume ratio of internal phase to organic phase (1/1), volume ratio of emulsion phase to external phase (1/5) and stirring speed (300 rpm)) were also influential on improving the stability (about 0.2% breakage) and on achieving the most stable emulsion. The membrane with the highest stability was employed to extract acridine orange with various concentrations (10, 20 and 40 ppm) from water. The emulsion liquid membrane prepared with n-octane as the best solvent almost removed 99.5% of acridine orange from water. Also, the prepared liquid membrane eliminated completely (100%) other cationic dyes (methylene blue, methyl violet and crystal violet) from water demonstrating the efficacy of prepared emulsion liquid membrane in treatment of dye polluted waters.

폐플라스틱 분해를 위한 알칸 교차 복분해 반응 (Cross Alkane Metathesis Reaction for Waste Plastic Degradation)

  • 김주은;안광진
    • 공업화학전망
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    • 제24권2호
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    • pp.22-30
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    • 2021
  • 현재 인류는 플라스틱(plastic) 세상에 살고 있다. 의류, 식품, 주거 생활 곳곳에 플라스틱이 존재하며, 플라스틱이 없는 세상은 상상조차 할 수 없다. 하지만, 플라스틱 사용량 증가에 따른 폐플라스틱의 배출량의 증가는 심각한 환경문제들을 야기하여 생태계뿐만 아니라 인간에게도 위협이 되고 있다. 이를 해결하기 위한 방법으로 단순히 폐플라스틱의 처리에 그치지 않고, 이를 활용하여 새로운 고부가가치의 생성물을 제조하는 플라스틱 업사이클링(plastic upcycling) 시스템이 최근 주목을 받고 있으며, 현재 다양한 형태로 연구개발이 진행되고 있다. 그 중의 한가지로 본 기고문에서는 알칸 교차 복분해(cross alkane metathesis) 반응을 소개한다. 알칸 교차 복분해 반응은 수소화/탈수소화(hydrogenation/dehydrogenation) 반응과 올레핀 복분해(olefin metathesis) 반응으로 이루어져, 탈수소화 반응 후 생성된 이중결합 탄소를 갖는 두 개의 알켄 화합물이 자리바꿈을 통해 새로운 이중 결합을 형성하는 반응이다. 이 촉매반응 과정이 반복되면 저분자화된 새로운 알칸 화합물을 생성되는데, 이는 기존의 플라스틱 처리방식인 열분해 및 촉매 분해 공정보다 낮은 반응온도를 요구한다. 또한 이를 통해 상대적으로 높은 순도의 가솔린 및 디젤을 생성할 수 있기 때문에 폐플라스틱 처리 공정의 새로운 대안기술이 될 수 있다. 본 기고문에서 폐플라스틱 중 가장 큰 비중을 차지하는 폴리에틸렌을 처리하는 대안기술로써 알칸 교차 복분해 반응의 메커니즘과 및 촉매의 역할, 그리고 반응성에 영향을 주는 인자에 대해 기술한다.

Use of N-alkanes to Estimate Intake and Digestibility by Beef Steers

  • Premaratne, S.;Fontenot, J.P.;Shanklin, R.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권11호
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    • pp.1564-1568
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    • 2005
  • The objective of the study was to evaluate the use of n-alkanes to estimate DM intake and digestibility by beef cattle. Six steers were blocked (3 blocks, 2 animals/block) according to the body weight (279${\pm}$19 kg) and randomly allotted within blocks to two diets (3 steers/diet). A second trial was conducted with the same animals (321${\pm}$18 kg) after 36 days (d), using a switch back design. The diets consisted of two types of chopped sun-cured hay, alfalfa (Medicago sativa L) hay, or fescue (Festuca arundinacea Schreb) and alfalfa mixture, which were fed in equal amounts to steers. Animals were dosed with $C_{32}$ and $C_{36}$ alkanes, employing an intra-ruminal controlled-release device at the beginning of each trial. Hay intake per animal was measured from d 6 to 12 and sub samples were taken for chemical analysis. Rectal samples of feces were taken from each animal once/daily from d 8 to 14, freeze dried, and ground prior to alkane analysis. Alkanes were extracted from ground hay and feces. Feed intake was calculated from the dose rate of $C_{32}$ alkane and, the herbage and fecal concentrations of adjacent odd ($C_{33}$ or $C_{31}$) and even ($C_{32}$) chain length alkanes. Crude Protein, NDF, ADF, ash concentrations and In vitro dry matter digestibility (IVDMD) were 17.7, 42.2, 28.4, 7.9 and 71.7 for alfalfa, and 12.4, 56.5, 30.4, 6.9 and 69.1% for fescue/alfalfa mixture, respectively. For both diets, intake estimated from $C_{33}$:$C_{32}$ ratio was not different from the measured intake, but intake estimated from $C_{31}$:$C_{32}$ ratio was lower (p<0.05), than the measured intake for both diets. The average estimated forage intake from $C_{33}$:$C_{32}$ ratio was 4.86 and 0.69% below than the measured intake for alfalfa and, fescue/alfalfa mixed diets, respectively. The respective estimates with $C_{31}$:$C_{32}$ ratio were 9.59 and 11.33% below than the measured intake. According to these results, alkane $C_{33}$:$C_{32}$ ratio is better than alkane $C_{31}$:$C_{32}$ ratio for the estimation of intake by beef steers.

석탄 연소 시 배출되는 응축성 미세먼지의 유기 성분 (Organic Compounds in Condensable Particulate Matter Emitted from Coal Combustion)

  • 박진;이상섭
    • 청정기술
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    • 제29권4호
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    • pp.279-287
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    • 2023
  • 석탄 연소 시 배출되는 미세먼지는 여과성 미세먼지(FPM)와 응축성 미세먼지(CPM)로 구분된다. CPM은 기존의 대기방지시설로 제어가 어려워 CPM의 특성을 파악하기 위한 연구가 진행되고 있다. 응축성 미세먼지(CPM)를 구성하는 성분은 크게 무기성분과 유기성분으로 나눌 수 있다. CPM의 무기성분 중에서 상당한 비율을 차지하는 이온성분에 대해서는 많은 정량분석 결과가 나와 있으나, 유기성분에 대해서는 알려진 바가 적다. 특히 유기성분에 대한 정량분석의 결과가 필요한 상황이다. 본 연구에서는 실험실 규모 석탄 연소로에서 배출되는 CPM의 유기성분 중 방향족 탄화수소(toluene, ethyl benzene, m,p-xylene, o-xylene)와 탄소 수 10부터 30까지의 n-alkane을 정량분석하였다. 실험 결과 방향족 탄화수소 중에서는 toluene이 CPM 유기성분의 1.03%를 차지하여 가장 높았다. 그러나 ethyl benzene, m,p-xylene, o-xylene이 차지하는 함량은 각각 평균 0.11%, 0.18%, 0.51%로 낮은 값을 나타내었다. 반면에 n-alkane 중에서는 triacontane(C30)이 2.64%, decane(C10)이 2.05%로 높은 함량을 보여주었다. 다음으로 dodecane(C12), tetradecane(C14), heptacosane(C27)의 순으로 함량이 높았는데, 이는 toluene 보다 높은 수준이었다. 농도가 검출된 n-alkane 물질들은 tetracosane(C24)만 제외하고 ethyl benzene, m,p-xylene, o-xylene보다 높은 함량을 보였다.

Biodegradation of Hydrocarbons by an Organic Solvent-Tolerant Fungus, Cladosporium resinae NK-1

  • Oh, Ki-Bong;Mar, Woong-Chon;Chang, Il-Moo
    • Journal of Microbiology and Biotechnology
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    • 제11권1호
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    • pp.56-60
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    • 2001
  • A kerosene fungus of Cladosporium resinae NK-1 was examined for its ability to degrade individual n-alkanes and aromatic hydrocarbons by gas chromatography-mass spectrometry, and its organic solvent-tolerance was investigated by making use of the water-organic solvent suspension culture method. It grew on a wide range of solvents of varying hydrophobicities and it was found to have tolerance to various kinds of toxic organic solvents (10%, v/v) such as n-alkanes, cyclohexane, xylene, styrene, and toluene. A hydrocarbon degradation experiment indicated that NK-1 had a greater n-alkane degrading ability compared to that of the other selected strains. C. resinae NK-1, which could utilize 8-16 carbon chain-length n-alkanes of medium chain-length as a carbon source, could not assimilate the shorter chain-length n-alkanes and aromatic hydrocarbons tested so far. The n-alkane degrading enzyme activity was found in the mycelial extract of the organism.

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슬러지 식종에 따른 디젤연료에 오염된 토양내 n-alkane 및 isoprenoid의 변화

  • 이태호;박현철;최선열;박태주
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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    • pp.131-134
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    • 2004
  • Several physical and chemical methods have been used for remediation contaminated by oils. However the cost was very high and secondary pollution rose during treating. The purpose of this study was to comprision TPH (total petroleum hydrocarbon) removal from artificially contaminated soil by diesel with and without seeding anaerobic digested sludge. After 120 days of overall at 35$^{\circ}C$, removal efficiency of TPH with seeding sludge was 2-3 times higher than blank. Also, the more amount seeding sludge, TPH removal efficiency and CH$_4$ content more obtained. It was sad that seeding of anaerobic digested sludge was a good method for enhancing TPH removal efficiency without increasing operating cost. Sulfate, nitrate-reducing, methanogenic condition were evaluated for alkane, isoprenoid as target contaminated soil.

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광주지역 여름철 대기 중 주야간 VOC 농도 특성 (Atmospheric Concentrations of Volatile Organic Compounds(VOC) of Day/Night Periods During the Summer Season in Kwangju)

  • 이영재;신대윤;이학성;강병욱;한종수
    • 한국대기환경학회지
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    • 제17권2호
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    • pp.169-177
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    • 2001
  • The concentrations of ambient volatile organic compounds (VOC) were investigated from the Kwangju area. A total number of sixty six sample were collected and analyzed during day/night periods from June to September 1999. Each of the canister sample ws analyzed for alkane and aromatic compounds using a GC/MSD sys-tem. The concentration of VOC in mean day/night time, when compared, was in the order: toluene(16%)> isobu-tane(14%)= acethylene(14%)> propane(12%)> ethane(11%)> butane(9%). The VOC concentrations were gene-rally higher during the daytime than the nighttime. The VOC with light weight(such as an alkane group, $C_2$-C(suh)5) showed generally higher concentrations during day/nighttime than the VOC with heavy weight (such as an aromatic group). High correlations were among the VOC emitted from the similar sources.

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