잔사유의 경질화

이문득,이인철 ( Moo Deuk Lee,In Chul Lee ) 한국화학공학회 1982 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.20 No.3

The shortage of crude oil supply placed an increased emphasis on methods of upgrading petroleum residue, heavy oil bearing sands. However, the high metal content of these stocks will result in poisoning of the catalysts used in processes such as catalytic craking, hydrocracking and hydrotreating. For treatment of high metal feedstocks, processes such as coking, deasphalting, use of a hydrogen-donor solvent, extraction with acid, and precititation with a polar solvent are used. Selection of the most economic process route for residuum conversion is not straightforward; however, of crude oil price eontinues growing upward more rapidly than solid fuels do and if high sulfur tar and coke prices remain comparable with those of other fuels, then processes for elimination of high sulfur by-products will become more attractive. Withe this in view, it is apparent that residuum hydroprocessing will play a major role in residuum conversion in the future.

무기화학공업의 현황과 전망 (2) ; 해수이용공업 : 제염공업의 현황

이문득 한국화학공학회 1984 NICE Vol.2 No.1

물 - 메탄올 혼합용매내에서의 NaCl , CaCl2 및 LaCl3 의 분몰랄부피 및 Debye - Huckel 이론의 적용성에 관한 연구

이문득,임성섭 한국화학공학회 1985 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.23 No.4

물-메탄올 혼합용매내에서 NaCl, CaCl₂ 및 LaCl₃의 밀도를 25℃에서 측정하여 전해질과 이온의 분몰랄부피(V￣₂^o & ￣V_(ion)^o)를 구한 결과, Debye-Hu¨ckel 이론의 적용성은 Nacl>CaCl₂>LaCl₃의 순서로 감소하며 혼합용매중의 메탄올 함량이 증가함에 따라 감소하였다. 또한 이온의 electrostriction 분몰랄부피 (V￣^o_(elect))는 물보다 메탄올에서 훨씬 큰 값을 가지며 양이온의 원자가가 증가함에 따라 증가하였다. 양이온의 원자가가 증가함에 따른 V￣^o_(elect) in water, V￣^o_(elect) in methanol 및 (V￣^o_(elect) in methanol-V￣^o_(elect) in water) 값의 증가분은 각각 25, 55 및 30㎖/mole정도였다. 0.5∼0.7몰분율의 메탄올까지는 (즉, 혼합용매중의 비교적 물이 많은 영역에서는) 이온주위에서 선택적수화가 존재하며, 이 혼합용매중의 물의 문턱함량을 넘어서면 용매화층이 바뀌면서 용매의 전기적 억압이 급격히 증가함을 알았다. Densities of solutions of NaCl, CaCl₂ and LaCl₃ in a series of water-methanol mixtures have been measured at 25℃. The partial molal volumes of salts V￣₂^o and the ionic partial molal volumes V￣_(ion)^o in water-methanol mixtures have been determined. It was found that the applicability of the Debye-Hu¨ckel theory decreases in the order Nacl>CaCl₂>LaCl₃ and decreases with increasing methanol content in water-methanol mixtures, and that the electrostriction partial molal volumes of ions V￣^o_(elect) are greater in methanol than in water and increase with the valency of the cation. The increments of V￣^o_(elect) in water, V￣^o_(elect) in methanol, and ( V￣^o_(elect) in methanol V￣^o_(elect) in water) with the valency of the cation are approximately 25, 55 and 30 ㎖/mole, respectively. The results also indicate that up to 0.5∼0.7 mole fraction of methanol (i.e., in water-rich regions of water-methanol mixtures) the preferential hydration around ion occurs, while above this threshold content of water in these mixtures the change of the solvation layer results in the strong electrostriction of the solvent.

수산화마그네슘의 침강속도에 미치는 반응조건의 영향

이문득,한승기 한국화학공학회 1988 NICE Vol.6 No.1

가스법에 의한 염기성 탄산마그네슘 제조에 관한 연구 : 2. 수산화마그네슘 제조에 관하여 2. Preparation of Magnesium Hydroxide

이문득 한국화학공학회 1969 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.7 No.3

Experimental works on the production of magnesium hydroxide with fast sedimentation velocity and low calcium content have been conducted using saline water and dolomite. Best result was shown to be obtained by using 3% dolime water and 1.2 times of theoretical amount for saline water. The coagulation constant of 0.42% magnesium hydroxide in 2.27% NaCl solution was found to be -1.1∼1.5 × 10². The calcium content of Mg(OH)₂ and its sedimentation velocity was found to be inversely related, and addition of chlorides to Mg(OH)₂ solution increased flocculation in the order, CaCl₂>NaCl>MgCl₂ while addition of hydroxides had deflocculation effect in the order Ca(OH)₂>NaOH>Mg(OH)₂>NH₄OH This shows that chlorides and hydroxides have opposite effect on the sedimentation velocity of Mg(OH)₂, and thus Mg(OH)₂ in basic solution may be concluded to be in an unstable colloidal state of Mg(OH)₂/OH Coagulation rate of magnesium hydroxide in 2.27% NaCl solution was found to increase with the period of agitation, and increase in calcium content was observed with the sedimentation velocity, while in the solution which do not contain NaCl the converse was true.

까스법에 의한 염기성탄산마그네슘 제조에 관한 연구 : 1 . 염기성탄산마그네슘의 건조에 관하여 1 . Drying of Basic Magnesium Carbonate

이문득 한국화학공학회 1968 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.6 No.4

The critical moisture content of basic magnesium carbonate has been determined to be about 150%(D. B) based on the characteristic curve for drying, obtained by both larboratory and pilot plant Tunnel Dryer methods. Temperature, humidity, flow rate, size and thickness of the feed material, and direction of air flow had large effect on drying in the constant rate period, but had little effect in the falling rate period. The optimum operation condition for drying with tunnel dryer had also been investigated. The tunnel dryer designed in this work had the following characteristics : critical moisture content Wc=1.47, eguilibrium moisture content, We=0.0l ; initial moistur content, W₁=4.00 ; moisture content at time, W₂=0.16 (t=9 hrs) : inlet air humidity=50% at 20℃ ; out let air humidity=60% at 70℃ ; preheated air temp=120℃, overall heat efficiency, over 60%.

수산화탄산마그네슘의 생성기구에 관한 연구

이문득,한승기 한국화학공학회 1985 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.23 No.2

수산화탄산마그네슘의 생성기구를 X-선회절분석, 열시차분석 및 화학분석을 행함으로써 고찰하였다. 시료들은 반응온도, 반응시간, 건조온도등의 제조조건을 변화시켜 가면서 제조하였다. 반응온도가 증가함에 따라 Nesquihonite는 Hydromagnesite로 분해되며, 이 과정의 중간물질로서 Dypingite가 존재한다는 사실을 알았으며, 반응시간이 길어지면 초기의 Nesquihonite와 유사한 결정은 붕괴되어 미지의 물질로 된 후 재차 Nesquihonite로 재결정됨을 확인하였다. Nesquihonite에 대한 건조온도의 영향과, 이것의 Hydrothermal반응을 고찰한 결과, Nesquihonite가 수산화탄산마그네슘으로 변환되기 위해서는 수분의 존재가 필요함을 알았다. The formation mechanism of basic magnesium carbonate has been investigated using X-ray diffractometry, Differential thermal analysis and chemical analysis. Samples were prepared by varying the conditions of preparation, such as reaction temperature, reaction time and drying temperature. As reaction temperature increased, Nesquihonite decomposed into Hydromagnesite, which had Dypingite as an intermediate. As reaction proceeded, Nesquihonite-like crystal was formed initially, which transformed to unknown compound and then recrystallized to Nesquihonite. The effect of drying temperature on Nesquihonite, and hydrothermal decomposition of it were investigated also. With these results, it could be concluded that moisture was necessary for Nesquihonite to decompose into basic magnesium carbonate.

전해질 수용액의 구조와 성질 Ethanol - 물 혼합용매에서의 Tetraalkylammonium Halides 의 점도에 관한 연구

이문득 한국화학공학회 1972 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.10 No.6

Tetraalkylammonium halide의 ethanol-물 혼합용매에서의 상대점도를 30, 35 및 40℃에서 측정하여 Jones-Dole식으로 점도계수 B값을 구하고, 또 B값의 가성성으로부터 ionic B값을 계산하여 tetraalkylammonium 및 halide 이온의 점성흐름에 대한 효과를 검토하여 점성흐름에 대한 활성화에너지 및 엔트로피의 입장에서 전해질의 전하효과와 알코올 혼합으로 인한 물 구조의 변화를 해석해 보았다. Halide 이온은 모두 negative B값을 가지며 0.1∼0.2 몰분율 ethanol에서 물 구조 파괴효과가 최고이고, 그 효과는 I^->Br^->Cl^- 순서로 감소하는데 비해 tetraalkylammonium 이온의 B값은 Me₄N^+<Et₄N^+<n-PrN^+<n-Bu₄N^+ 순서로 증가하며 모두 positive 값을 갖는다. Me₄NX는 온도가 상승함에 따라 B값이 증가하고, Pr₄NX는 이와 반대이다. 점성흐름 입장에서 고찰하면 Me₄NX는 활성화 엔트로피 효과가 지배적이고, Pr₄NX는 활성화 에너지가 지배적이다. The relative viscosities of a series of homologous tetraalkylammonium halides Me₄NBr, Me₄NCl, Me₄NI, n-Pr₄NCl, n-Pr₄NBr, n-Pr₄NI, Et₄NI and n-Bu₄NI in a series of ethanol-water mixtures have been determined at 30, 35 and 40℃. The viscosity data have been enterpreted in terms of viscoity A- and B-coefficients calculated from the Jones-Dele equation, η_r=1+A√C+B·C. The energies and entropies of activation for viscous flow have also been calculated for a number of ionic species. The results indicate that the structure breaking effect of halide ions are maximum at 0.1-0.2 mole fraction ethanol. Structure breaking effects decrease in the order I^->Br^->CI^-. The viscosity B-coefficients of these salts are all positive and increase in the order Me₄N^+<Et₄N^+<n-Pr₄N^+<n-Bu₄N^+ and decrease in the order for the halide Cl^->Br^->l^-. The B-coefficient of Me₄NX increases and that of Pr₄NX decreases with increase in temperature. The energy and entropy of activation of these salts are calculated and the influence of such ions upon the binary solvent structure is discussed.

이온교환수지에 의한 방사성 폐액의 처리

이문득 한국화학공학회 1963 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.1 No.2

This paper describes a preliminary study of the absorption and desorption of ion exchange processes involving radioactive isotopes. Cation exchange DOXEX 50-x8 (H) removes the bulk of radioactivity of alkali and alkali earth metal, Co, Mn in pH 10, Fe, Cu in pH 7, and Fe, Cr in pH2 solutions. But anion exchange Amberlite IRA-400 (OH) usually absorb it in neutral were best. Regenerant of 5.6N nitric acid for cation and 1 N sodium hydroxide for anion were required 3 to 5 times of resin bed. Treatment of fission product of 10^(-4) c/ml (267.9 p.p.m. as NaCl)with mixed bed(8.3Ø×100cm) flowing at a rate 40 1/hr provides complete removal of various impurities and give an effluent having an activity level below 10^(-7) c/ml (0.0 p.p.m. as NaCl)

연구발표논문초록 : 가스법에 의한 염기성탄산마그네슘 제조에 관한 연구 - 3 . 수산화마그네슘 현탁액에 의한 탄산가스의 흡수 -

이문득,이정자 한국화학공학회 1971 정기총회초록집 Vol.- No.-