• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.158.2-158.2
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• 2011

DME is acronym of dimethyl ether, which is spotlighted as an ideal fuel to produce hydrogen due to its high hydrogen/carbon ratio, high energy density and easiness to carry. In this research, we calculated thermodynamic hydrogen (or syngas) yield from DME autothermal reforming and compared to other fuels. The reforming efficiency was about 80% above $700^{\circ}C$. Lower OCR has higher reforming efficiency but, it requires additional heat supply since the reactions are endothermic. SCR has no significant effect on the reforming efficiency. The optimized condition is $700^{\circ}C$, SCR 1.5, OCR 0.45 without additional heat supply. Comparing to other commercial gaseous fuels (methane and propane), DME has higher selectivity of $H_2O$ and $CO_2$ than the others due to the oxygen atom in the molecule. To apply DME autothermal reforming to real system, a proper catalyst is required. Therefore, it is performed the experiment comparing various novel metal catalysts based on CGO. Experiments were performed at calculated condition. The composition of product was measured and reforming efficiency was calculated. The catalysts have similar efficiency at high temperature(${\sim}800^{\circ}C$) but, CGO-Ru has the highest efficiency at low temperature ($600^{\circ}C$).

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.4
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• pp.474-480
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• 2011

Hydrocarbon is required to be converted to pure hydrogen without carbon monooxide (CO) for polymer exchange membran fuel cell (PEMFC) applications. In this paper, CO cleaning processes as the downstream of Dimethyl ehter (DME) autothermal reforming process were performed in micro-reactors. Our study suggested two kinds of water gas shift (WGS) reaction process: High Temperature shift (HTS) - Low Temperature shift (LTS), Middle temperature shift (MTS). Firstly, using perovskite catalyst for MTS was decreased effieiciency since methanation. Using HTS-LTS the CO concentration was decreased about 2% ($N_2$ & $H_2O$ free) with the reaction temperature of $420^{\circ}C$ and $235^{\circ}C$ for HTS and LTS, respectively. As the final stage of CO cleaning process, preferential oxidation (PROX) was applied. The amount of additional oxygen need 2 times of stoichiometric at $65^{\circ}C$. The total conversion reforming efficiency of 75% was gained.

• YAKHAK HOEJI
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• v.11 no.1_2
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• pp.7-16
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• 1967

A yellowish microneedles, $C_{28}$ H$_{32}$ $O_{14}$ ${\cdot}$ I$_{1}$/$_2$, H$_{2}$O, m.p.262-$4^{\circ}$ , [${\alpha}$$_{D}^{20}$= -71,$43^{\circ}$(C = 0.42, pyridine), its acetate m.p.123-5.deg., were obtained in 0.3% yield from the leaves of Chrysanthemum sibiricum F$_{ISCHER}$. This substance is insoluble in water and the usual organic solvents except pyridine and ethylene glycol and, is not decomposed by dilute mineral acids but undergoes decomposition on being boiled in 60% H$_{2}$SO$_{4}$ or 35% HCl, giving one moel each of acacetin, glucose and rhamnose. It was not hydrolysed with a rhamnodiastase preparation obtained from the seeds of Rhamnus koraiensis. After permethylation of it, the uncrystallized product was hydrolysed and apigenin-5,4'-dimethyl ehter, m.p.$262^{\circ}$ was obtained, indicating that the disaccharide residue is at the 7 position of acacetin. Partial hydrolysis of this acacetin-7-rhamnoglucoside in cyclohexanol with formic acid gave acacetin-7-glucoside, m.p.246.deg. and rutinose, identifying them with authentic specimen on a paper chromatography. It was thus identified as linarin(acacetin-7-rutinoside) by means of mixed fusion, of paper partition chromatography and of its derivatives. Zemplen and Bognar suggested that the glucosidic linkage of linarin is .betha. by means of synthesis of this substance. But there is no evidence whether it is hydrolysed by emulsin or maltase or not. Linarin itself was not hydrolysed by an emulsin existing in the seed of Apricot or a maltase, but acacetin-7-glucoside(tilianin) which obtained from linarin gave acacetin and glucose on hydrolysis with the same emulsin and accordingly the glucosidic linkages of linarin and tilianin are thus regarded as ${\beta}$.