• Title/Summary/Keyword: alkali hydroxide

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Uitlization of Ligno-cellulosic Biomass(I) - Manufacture of Explosion Apparatus and Composition of Explode Wood - (목질계(木質系) Biomass의 이용(利用)(I) - 폭쇄장치(爆碎裝置)의 제작(製作) 및 폭쇄재(爆碎材)의 조성(組成) -)

  • Lee, Jong-Yoon;Park, Sang-Jin;Lee, Seok-Gun;Cho, Nam-Seok;Chang, Jun-Pok;Ann, Byung-Jo
    • Journal of the Korean Wood Science and Technology
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    • v.17 no.2
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    • pp.65-73
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    • 1989
  • Steam explosion process is an efficient pretreatment method for sparating and utilizing wood main components has attracted attention in utilization of ligno-cellulosic biomass. In order to obtain the effective pretreatment condition. this study was made explosion apparatus. examined the composition. extraction of exploded wood. Wood chips of pine(Pinus densiflora oak (Quercus serrata) and birch wood (Belula platyphylla var. japonica) were treated with a high pressure steam(20-30 kg/$cm^2$, 2-6 minutes). The results can be summarized as follow; In analysis of exploded wood(EXW). It was found arabinose residues rapidly decreased with increasing of steaming time and pressure. Extractives of EXW with sodium hydroxide increased with increasing of steaming-time and- pressure especially extractives 1% sodium hydroxide has higher than other extracted method extractives of hard wood(oak, birch) has higher than pine wood. In EXW extracted with sodium hydroxide and methanol lignin was partially delignified alkali extraction was more delignified than methanol extraction hardwood than pine wood.

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Formation of an Aluminum Hydroxide Fiber by a Hydrolysis of Aluminum Nano Powder (알루미늄 나노 분말의 수화반응에 의한 수산화알루미늄 형성)

  • Lee Geunhee;Oh Young Hwa;Rhee Chang Kyu;Kim Whung Whoe
    • Korean Journal of Materials Research
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    • v.15 no.3
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    • pp.172-176
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    • 2005
  • Formation of aluminum hydroxide by a hydrolytic reaction of nano aluminum powder synthesized by a pulsed wire evaporation (PWE) method has been studied. The type and morphology of the hydroxides were investigated with various initial temperatures and pHs. The nano fibrous boehmite (AlOOH) was formed predominantly over $40^{\circ}C$ of the hydrolytic temperature in acid solution, while the bayerite $(Al(OH)_3)$ was formed predominantly below $30^{\circ}C$ in alkali solution with a faceted crystalline structure. As a result the boehmite showed a much larger specific surface area (SSA) than that of bayerite. The highest SSA of the boehmite was about $409\;m^2/g$.

A Study on the Property and the Skin Irritability of the Reclaimed Soap (폐유을 이용한 재생비누의 특성 및 피부자극도에 대한 연구)

  • 하금;이혜자;유혜자
    • Journal of the Korean Home Economics Association
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    • v.36 no.1
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    • pp.1-11
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    • 1998
  • The purpose of this study is to find troubles in producing and using the reclaimed soaps to get the solutions of their troubles. Five kinds of reclaimed soaps were taken from religious or civic organizations and nine kinds of soaps were made by adding sodium hydroxide of different concentrations to the used vegetable oil in our laboratory. Washing efficiency, pH test, BOD, and skin irritability of the reclaimed of manufactured soaps were examined. The washing efficiency of the manufactured soaps were ±80%. The percent of free-alkali tended to increase as the amount of NaOH increased. The skinirritability was proportional to the amount of NaOH added. To make the reclaimed soap, the best percent of NaHO to used oil is 17% or 18% and this ratio(17%∼18%) should be kept. Manufactured soaps by this ratio have good apperance condition and washing efficiency. And also they have low skin irritability and free-alkali. This study has the limitations that the skin irritability test can have individual and the collected soaps couldn't represent all kinds of recaimed soap.

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Alkali Gelatinization of Starches Isolated from Various Hydration Groups of Milled Rice (수화그룹별 쌀 전분의 알카리 호화)

  • Kim, Sung-Kon;Chung, Hye-Min
    • Applied Biological Chemistry
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    • v.29 no.1
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    • pp.29-35
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    • 1986
  • Viscosity development pattern, in aqueous sodium hydroxide, of rice starches isolated from various hydration groups of milled rice was investigated. The maximum viscosity and viscosity development rate of Japonica rice starches at a given alkali concentration were loswer than those of J/Indica counterparts. The difference in the viscosity development rate of starches by increment of 0.1N (0.02 meq/g) was greater in J/Indica rice starches in comparison with Japonica ones. Viscosity of rice starch was not correlated to that of rice flour and to hydration rate of milled rice.

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Preparation of composite adsorbent for low level $CO_2$ (저농도 $CO_2$ 포집을 위한 복합흡착제 제조)

  • Park, Young-Koo;Jo, Young-Min;Kim, Ho-Kyoung
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.2
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    • pp.257-264
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    • 2008
  • Adsorption is one of the most efficient method for the separation of low level carbon dioxide. In order to enhance the adsorption capacity, a few additives such as alkali hydroxides were combined with the zeolitic sorbents. As a result of the experimental examination by applying the $CO_2$ flow of 3000 ppm, the composite sorbent showed the improved quality to a certain degree and the added binder was also found to contribute to better adsorption.

Treatment of Hydrogen Fluoride Generated from the F-gases Decomposition Processes

  • Park, Jun-Hyeong;Choi, Chang Yong;Kim, Tae-Hun;Shin, InHwan;Son, Youn-Suk
    • Asian Journal of Atmospheric Environment
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    • v.10 no.4
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    • pp.190-196
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    • 2016
  • The objective of this study is to obtain the optimal conditions to remove hydrogen fluoride (HF) generated from a variety of F-gas treatment processes. First, we selected $Ca(OH)_2$ and $CaCO_3$ as a reactant among the various alkali salts which have a high removal efficiency and a competitive price by forming a calcium fluoride precipitate. Additionally, various factors were investigated to improve the removal efficiency of HF. The conditions such as the settling time, agitating time and intensity, reaction temperature, and pH were considered as main factors. As a result, in the treatment process to remove HF through Ca-based alkali salts, the optimal conditions were a 120 min settling time, 30 min of agitation at 100 rpm, a pH of 4-8, and a reaction temperature of $40^{\circ}C$.

A Study of the Strength and Durability Properties on Recycled Aggregate Concrete and Blain of Blast Furnace Slag (고로슬래그의 분말도 및 순환골재 치환율에 따른 콘크리트의 강도 및 내구적 특성에 관한 연구)

  • Lim, Myung-Kwan;Park, Moo-Young;Jung, Sang-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.7 no.4
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    • pp.101-108
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    • 2007
  • Furnace slag powder used currently in Korea needs to add special functions in response to the increase of large-scale projects. In addition, it is advantageous in that it has a lower hydration heat emission rate than ordinary Portland cement and improves properties such as the inhibition of alkali aggregate reaction, watertightness, salt proofness, seawater resistance and chemical resistance. However, furnace slag powder is not self -hardening, and requires activators such as alkali for hydration. Accordingly, if recycled fine aggregate, from which calcium hydroxide is generated, and furnace slag, which requires alkali stimulation, are used together they play mutually complementary roles, so we expect to use the mixture as a resource-recycling construction material. Thus the present study purposed to examine the properties and characteristics of furnace slag powder and recycled aggregate, to manufacture recycled fine aggregate concrete using furnace slag and analyze its performance based on the results of an experiment, to provide materials on concrete using furnace slag as a cement additive and recycled fine aggregate as a substitute of aggregate, and ultimately to provide basic materials on the manufacturing of resource-recycled construction materials using binder and fine aggregate as recycled resources.

Characteristics of geopolymer based on recycling resources (재활용 폐자원에 따른 지오폴리머의 특성변화 연구)

  • Kim, Yoo-Teak;Kim, Hyun-Jung;Jang, Chang-Sub
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.22 no.3
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    • pp.152-157
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    • 2012
  • In this study, geopolymer was prepared with reject ash and blast furnace slag using NaOH as an alkali activator and water glass. The aim of this study was to investigate the compressive strength variation according to the contents of NaOH and water glass and replacement ratio of reject ash (RA) and blast furnace slag (BS). The compressive strength measured after 28 days was 38.91 MPa for the geopolymer which consist of 100 % of BS with 1 wt% NaOH and 3 wt% water glass. The major factor for improving compressive strength was the alkali activator proportion and the replacement ratio of RA and BS.

Development of slag based Shirasu geopolymer

  • Katpady, Dhruva Narayana;Takewaka, Koji;Yamaguchi, Toshinobu
    • Computers and Concrete
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    • v.20 no.1
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    • pp.77-84
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    • 2017
  • Shirasu, a pyroclastic flow deposit, showed considerable performance as aluminosilicate source in geopolymer, based on past research. However, the polymerization reactivity was somewhat lower compared to the traditional fly ash based geopolymer even though the long-term strength was fairly good. The present study concentrates on the development of higher initial strength performance of Shirasu based geopolymer by utilizing ground granulated blast furnace slag as an admixture. Mortars with various mix proportions were adopted to study the effect of parametric changes on strength development along with the addition of slag in different percentages. A combination of sodium hydroxide and sodium silicate was used as alkaline activators considering parameters like molar ratios of alkali to geopolymer water and silica to alkali molar ratio. The mortars were cured at elevated temperatures under different curing conditions to analyze the effect on strength development. Compressive strength test, mercury intrusion porosimetry and X-ray powder diffraction were carried out to assess the strength performance and microstructure of slag-Shirasu based geopolymer. Based on the experimental study, it was observed that the initial and long-term strength development of Slag-Shirasu geopolymer were improved by the addition of slag.

Chlor-alkali Membrane Process and its Prospects (클로알칼리 멤브레인법과 전망)

  • Park, In Kee;Lee, Chang Hyun
    • Membrane Journal
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    • v.25 no.3
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    • pp.203-215
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    • 2015
  • Chlor-alkali (CA) membrane process is based on salined water electrolysis employing cation condutive polymer electrolytes, which has been used for the conventional production of both sodium hydroxide and chlorine gas. The CA membrane process has advantages such as relatively low environmental impacts and fairly reduced energy consumption, when compared with diaphragm and mercury process. In this review articles, basic concepts, fundamental characteristics, key technologies of CA membrane process are dealt with in detail. In addition, advanced technologies associated with CA membrane process are described. They include zerogap and oxygen depolarized cathode technologies to improve energy efficiency during the electrolysis. Carbon dioxide mineralization technology will also be introduced as an example of hybridization with different technologies. Finally, current market trend in CA membrane process will be presented.