• Title, Summary, Keyword: Base/acid ratio

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Studies of the Fusibility of Coal Ashes in Oxidizing and Reducing Conditions (산화성 및 환원성분위기에서 석탄회분의 용융성)

  • Park, Chu-Sik;Lee, Shi-Hun;Choi, Sang-Il;Yang, Hyun-Soo
    • Applied Chemistry for Engineering
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    • v.8 no.2
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    • pp.179-190
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    • 1997
  • To study the effects of chemical composition on the fusion temperatures of coal ashes, the chemical composition, mineral matter, and fusion temperature were studied with 54 kinds of coal ash samples including Korean anthracite coals. CaO, MgO and $Fe_2O_3$ were observed to be major fluxing elements in reducing and oxidizing atmosphere. The fluxing effect of $Fe_2O_3$ was increased more in reducing atmosphere. In a base/acid ratio, the fusion temperature decreased with increasing amounts of basic components. Nevertheless, the correlation between a fusion temperature and base/acid ratio was not shown well in a higher ratio of $Fe_2O_3/CaO$. The differences of fusion temperatures between oxidizing and reducing atmosphere showed close relationship with $SiO_2/Al_2O_3$ ratio rather than with $Fe_2O_3$ contents. Multiple regression was used to predict the fusion temperature of coal ashes, and it was established that the major predictors in oxidizing atmosphere were Base/Acid, $Fe_2O_3/CaO$, $SiO_2/Al_2O_3$, and $(SiO_2/A1_2O_3){\cdot}(Base/Acid)$ and Base/Acid, $Fe_2O_3/CaO$, $SiO_2$, and $TiO_2$ were major ones in reducing atmosphere.

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Comparison of Surface Characteristics and Adsorption Rate of Benzene Vapor According to Modifications of Activated Carbon (개질에 따른 활성탄의 표면특성과 Benzene 증기의 흡착속도 비교)

  • Lee, Song-Woo;Kam, Sang-Kyu;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.17 no.8
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    • pp.919-924
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    • 2008
  • The surface properties and adsorption rates of activated carbon modified with acid and base were compared. The distribution ratio of C and C-H on the surface of activated carbon were decreased by modification with acid and base, but the distribution ratio of C-O, C=O, and O=C-O were increased. Base modification damaged the surface of activated carbon more than acid modification, it caused the effect of 6 percent increments of surface area. Adsorption rate model was more suitable to second order equation than first order equation. Adsorption rate was controlled by adsorption in pore better than in surface.

Studies on the Organic Base Complexes and their Application to Analytical Chemistry. I. A Study on the Formation of Chlorpromazine Bromothymol Blue Complex and its Application to Analytical Chemistry. (4 유기염기착화합물의 분석화학적연구 I. Chlorpromazine Bromthymol Blue Complex 의 분석화학적연구)

  • 김차덕;심상혁;서정현
    • YAKHAK HOEJI
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    • v.9 no.1_2
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    • pp.14-17
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    • 1965
  • It has been known that the organic base complexes formed with the anionic acid base indicators are highly soluble in non-polar solvents but relatively insoluble in water. In the work reported here the formation of the complex between chloropromazine and bromothymol blue was studied and applied it to the determination of the base. The values to determine the binding ratio of the base with the indicator at pH 3.5 obtained from the application of Job's method of continuous variation and mol ratio method were both 1:1. From the application of this reaction to the determination of the base with carbon tetrachloride as the solvent for the extraction, fairy good results have been obtained.

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Production Biodiesel via In-situ Transesterification from Chlorella sp. using Microwave with Base Catalyst

  • Kalsum, Ummu;Kusuma, Heri Septya;Roesyadi, Achmad;Mahfud, Mahfud
    • Korean Chemical Engineering Research
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    • v.56 no.5
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    • pp.773-778
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    • 2018
  • In-situ transesterification of microalgae lipids using microwave irradiation has potential to simplify and accelerate biodiesel production, as it minimizes production cost and reaction time by direct transesterification of microalgae into biodiesel with microwave as a heating source. This study was conducted to research the effect of microwave irradiation with in-situ transesterification of microalgae under base catalyst condition. The process variables (reaction time, solvent ratio, microwave power) were studied using 2% of catalyst concentration. The maximum yield of FAME was obtained at about 32.18% at the reaction time of 30 min with biomass-methanol ratio 1:12 (w/v) and microwave power of 450 W. The GC MS analysis obtained that the main component of FAME from microalgal oils (or lipids) was palmitic acid, stearic acid and oleic acid. The results show that microwaves can be used as a heating source to synthesize biodiesel from microalgae in terms of major components resulting.

Properties of Carbon Black/SBR Rubber Composites Filled by Surface Modified Carbon Blacks

  • Dai, Shuang-Ye;Ao, Ge-You;Kim, Myung-Soo
    • Carbon letters
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    • v.8 no.2
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    • pp.115-119
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    • 2007
  • Properties of carbon blacks and carbon black/SBR rubber composites filled by surface modified carbon blacks were examined. Although the specific surface area of carbon blacks increased after the surface modifications with heat, acid, and base, there were no obvious changes in resistivity. The composites filled by heat treated carbon blacks showed a higher tensile strength and elongation than those filled by raw blacks. The acid and base treated carbon blacks filled composites also showed higher tensile strength but similar elongation values with those filled by raw blacks. With increasing loading ratio, both tensile strength and elongation increased, and appeared a maximum value at 30-40 phr. Modulus at 300% strain remained increasing with further loading of carbon blacks. At the same loading, the heat treated black filled composites showed similar modulus values with composites filled by raw blacks but for base and acid treated black filled composites much higher values were obtained. After the surface modification, the functional groups which played an important role in reinforcement action were changed.

Development of Computer Program for Menu Based on Nutrients and Food Preference (영양소와 식품기호도를 고려한 식단 작성 Computer Program의 개발)

  • 김은미
    • Journal of Nutrition and Health
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    • v.30 no.5
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    • pp.529-539
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    • 1997
  • The present study was to formulate a computer program to provide a menu based on a food preference survey of families in urban areas. A food preference survey was conducted by individual direct interviews of infants, children and old people in this study. In case other's food preferences were available, food menus considering all age groups could be made. Database III PLUS package was utilized for this study. The dBASE was loaded with a food compostion table of 339 different food items, along with data for amino acids and fatty acids for 171 and 43 food items respectively. Food preference, unit of food, and recommended dietary allowances were also incloded. This meun program system calculates nutrients in selected foods, and menu assessment was composed of several factors inculding energy ratio of carbohydrate : protein : fat, amino acid score, limiting amino acid, polyunsaturated fatty acid/saturated fatty acid(JP/S) ratio and Ca/P ratio.

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Dissolution Characteristics of ph-Dependent Antacid Granules Agglomerated in High Speed Agitation Type Speed Agitation Type Granulator

  • Choi, Woo-Sik;Lee, Jung-Sun
    • Archives of Pharmacal Research
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    • v.18 no.5
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    • pp.314-319
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    • 1995
  • Antacid granules were prepared by agglomeration and powder method in high speed agitation type granulator. The copmositions of the test antacids were sodium bicarbonate nad magnesium carbonate nad a coating material was powder of polyvinylacetal diethyl-aminocacetate (AEA) and an additive material was talc powder. The dissolution characteristics of base from the antacid granules were investigated to evaluate neutralization capacity of hydrochloric profile of base and neutralization behavior, the following results were obtained : The prepared granules showed a pH-dependent dissolution pattern of a base. The dissolution profile of a base was varied with addition of talc powder as well as coating amount of AEA. The relationship between the ratio of dissolution retarded time for 20% and 10% AEA. The relationship between the ratio of dissolution retarded time for 20% AEA coated granules $\theta_{20}/\theta_{10}$ and the diameter reduction of the granules was explained by the rate process of neutralization of hydrochloric acid.

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Production of Biodiesel from High Acid Value Oils using Amberlyst-15 (Amberlyst-15를 이용한 산가가 높은 유지로부터 바이오디젤의 생산)

  • Sim, Yeon-Ju;Kim, Eui-Yong
    • KSBB Journal
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    • v.25 no.5
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    • pp.483-489
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    • 2010
  • Biodiesel has attracted great attention as an alternative renewable energy source for the replacement of petroleumbased diesel fuel, yet its high production cost due to expensive oil feedstock remainsas the major economical obstacle. In this study, we investigated catalysts and reaction conditions for the acid catalyzed pre-conversion of free fatty acid (FFA) to fatty acid methyl ester (FAME) in cheap low-grade oils of high acid value. The NaOH base catalyzed reaction of vegetable oil of the initial acid value of 2 mg KOH/g led to a high FAME conversion above 95.4%, but the conversion abruptly decreased at higher initial acid values. This base catalyzed reaction was practically ineffective displaying the FAME conversion below 15% even at the initial acid value of 10 mg KOH/g by the severe saponification side reaction. Among the various catalysts studied for the pre-conversion of FFA to FAME, Amberlyst-15 was the most effective in reducing the acid value, and the optimum reaction condition identified was $65^{\circ}C$ with oil to methanol ratio of 1:3 and catalyst concentration of 15% (w/w). As the results, great enhancements in the overall biodiesel conversion were achievable via a consecutive reaction of the acid catalyzed FFA pre-conversion to FAME under the optimal condition obtained with Amberlyst-15 followed by the NaOH base catalyzed reaction, far above the extent which was obtainable by the single NaOH catalyzed reaction.

A Study of Chemical Properties and Fusibility of Korean Anthracite Coal Ash (국내 무연탄회의 화학조성 및 용융특성에 관한 연구)

  • Park, Cheol-Woo;Lee, See-Hoon;Shon, Eung-Kwon
    • Analytical Science and Technology
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    • v.5 no.4
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    • pp.433-441
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    • 1992
  • Chemical composition and fusibility of coal ash were measured for 23 Korean anthracite coals. The relationship between chemical properties and fusion temperature of coal ash was investigated. The slagging and fouling in firing the pulverized coal for boiler was assessed for the coal samples. It was found that most ashes contained more than 80% of $SiO_2$ and $Al_2O_3$ whereas less than 1% of $Na_2O$. And also fusion temperature of ashes occured relatively higher for Korean coals. Therefore it can be predictable that the slagging and fouling formation has a little problem in a pulverized coal firing system. A base/acid ratio did show a good correlation with fusion temperature for these coal ashes.

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Studies on the Fusibility of Fly Ash-Flux Mixtures (융제 첨가 비산회의 융융성 연구)

  • Yang, Hyun S.;Lee, Kyu C.;Park, Chu S.
    • Applied Chemistry for Engineering
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    • v.8 no.6
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    • pp.985-993
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    • 1997
  • The effects of CaO and MgO fluxes on the fusibility of fly-ashes were investigated for two different fly-ashes. A fusion temperature of mixtures of selected fly-ashes and fluxes were measured by the ASTM test method(D1857) and the differential thermal analysis. IDT of these samples added CaO and MgO as a fluxing agent dropped in the range of 114 to $294^{\circ}C$ and 80 to $224^{\circ}C$, respectively. Compared with ash fusion temperature to Base/Acid ratio, the lowest ash fusion temperature were measured in the range of 0.7 to 0.8 for CaO-fly ash mixtures and 0.3 to 0.4 for MgO-fly ash mixtures. As a result, MgO in small addition acted as a more effective flux than CaO. A conventional Base/Acid ratio and liquidus point of ternary diagram did not show a good correlation with ash fusion temperature for these samples. In pure fusion temperature of fly ash-mixtures, DTA was better method than ASTM test method.

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