• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.519-530
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• 2009

Reducing the emission of carbon dioxide, which is the main contributor to the green house effect, is becoming a global hot issue. Great attention has been thus given to utilization of carbon dioxide rather than just capturing and isolating it because it could convert carbon dioxide to high-value chemicals. In this paper, recent research trends are investigated on the catalytic conversion of carbon dioxide to syngas in the context of $CH_4$, dry-reforming, trireforming, and the electro-catalytic conversion of carbon dioxide through SOFC(Solid Oxide Fuel Cell) system. Research trends for utilizing syngas to high-value-added useful products, mainly fuel such as DME(Dimethyl Ether) are also discussed.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.97.1-97.1
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• 2011

Dimethyl ether (DME) is an attractive fuel as a hydrogen carrier for mobile PEMFC applications. However, its reforming technologies are rarely studied especially by using autothermal reforming (ATR) method. This work explored the impact of operating conditions to the performance of DME ATR. Temperature, Steam to carbon ratio(SCR), Oxygen to carbon ratio(OCR) and Gas hourly space velocity(GHSV) were considered as the operating conditions. As results, conversion efficiency was increased as the temperature increased, but saturated around $700^{\circ}C$. There was no significant effect of SCR on conversion efficiency, but high SCR led reactions in endothermic manner. High OCR substantially suppressed conversion efficiency, but it helped to sustain the temperature by stimulating exothermic reactions. Conversion efficiency was decreased as GHSV increased. The optimized operating conditions was suggested: $700^{\circ}C$, SCR of 1.5, OCR of 0.45 and GHSV below 15000/h and conversion efficiency was ~85% at the conditions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.6 s.261
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• pp.514-521
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• 2007

This study focused on the effects of the $CO_2$ gas concentration in fresh charge and induction air temperature on the combustion characteristics of homogeneous charge compression ignition with dimethyl ether (DME) fuel, which was injected at the intake port. Because of adding $CO_2$ in fresh charge, start of auto-ignition was retarded and bum duration became longer. Indicated combustion efficiency and exhaust gas emission were found to be worse due to the incomplete combustion. Partial burn was observed at the high concentration of $CO_2$ in fresh charge with low temperature of induction air. However, indicated thermal efficiency was improved due to increased expansion work by late ignition and prolonged bum duration. Start of auto-ignition timing was advanced with negligible change of burn duration, as induction air temperature increased. Burn duration was mainly affected by oxygen mole concentration in induction mixture. Bum duration was increased, as oxygen mole concentration was decreased.

• Journal of Hydrogen and New Energy
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• v.15 no.4
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• pp.283-290
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• 2004

The single-step process for conversion of syngas to DME give higher conversion than the syngas-to-methanol process. This arises because of a synergy among the three simultaneous reaction, methanol synthesis, methanol dehydration and water gas shift reaction, in the process. we would find the optimal condition of the process which these advantages. The optimal condition of DME synthesis reaction over a commercial $Cu/Zn/Al_2O_3$ catalyst and Hybrid catalyst in a fixed bed reactor. The syngas-to-dimethyl ether conversion was examined on various reaction condition (Temperature 473~553K, $H_2/CO$ ratio 1~3, Pressure 30'50atm, GHSV 1000~4000).

• Journal of the Korean Institute of Gas
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• v.12 no.3
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• pp.81-84
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• 2008

In this paper, the research was applied the mixture gas of Propane-DME (dimethyl ether) for being commercialization to residential gas ranges. In order to examine a correspondence between Korean Standard and thermal efficiency characteristics at each burner, experiments were performed with 100% Propane and the mixture gas of 80% Propane-20% DME. The experimental results were shown that the higher a mixture ratio of DME was used, the lower a thermal efficiency was gained. Those were due to low caloric value of DME. With 80% Propane-20% DME mixture gas, one of residential gas ranges was not satisfied the condition for the thermal efficiency value, 40%, Korean Standard. Consequently, the research needs about the standard for being commercialization to the mixture gas of Propane-DME.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.69-75
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• 2004

The present study is numerically investigated for the high pressure effects on the vaporization process of the DME droplet. The evaporation rate of DME droplets is about twice that of dodecane droplets at the same chamber condition. The DM droplet vaporization characteristics is parametrically studied for the wide range of the operating conditions encountered with the high pressure combustion process.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.163-167
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• 2004

Dimethyl ether(DME)는 대기 오염 문제와 에너지 문제가 대두됨에 따라 저공해 경유 대체 연료로 각광받고 있는 물질이다. 최근 들어 메탄올로부터 고체산 촉매를 이용하여 DME를 합성하고자 하는 연구가 활발히 진행 중이다[1-4]. 메탄올로부터 DME의 합성시 촉매로는 제올라이트나 SiO$_2$/${\gamma}$-Al$_2$O$_3$를 사용하기도 하지만 ${\gamma}$-Al$_2$O$_3$나 변형된 ${\gamma}$-Al$_2$O$_3$가 일반적으로 사용된다.(중략)

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.185-189
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• 2004

Methanol dehydration to dimethyl ether (DME) has been investigated over ZSM-5 zeolites and compared with that of ${\gamma}-Al_2O_3$. Although the catalytic activity was decreased with an increase in silica/alumina ratio, the DME selectivity increased. H-ZSM-5 and NaH-ZSM-5 zeolites were more active for conversion of methanol to DME than ${\gamma}-Al_2O_3$. $Na^+$ ion-exchanged H-ZSM-5 (NaH-ZSM-5) shows higher DME selectivity than H-ZSM-5 due to the selective removal of strong acid sites.

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.246-251
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• 2020

Dimethyl Ether(DME) engine use a highly efficient alternative fuel having a great quantity of oxygen and has a advantage no polluting PM gas. The existing DME fuel cam material is a highly expensive carbide alloy, and it is difficult to take a price advantage. Therefore the study of replacing body area with inexpensive steel material excluding piston shoe and contact area which demands high characteristics is needed. The development of WC-Ni base carbide alloy optimal bonding composition technique was accomplished in this study. To check out the influence of bonding temperature and time, bonding characteristics of sintering temperature was experimented. The hardness of specimen and bonding rate were measured using ultrasound equipment. The bonding state of each condition was excellent, and the thickness of mid-layer, temperature and maintaining time were measured. The mid-layer thickness according to bonding temperature and maintaining time were observed with optical microscope. We analyzed the micro-structural analysis, formation of bonding specimen, wafer fabrication and fuel cam abrasion test. Throughout this study, we confirmed that the fuel cam for DME engine which demands high durability against velocity and pressure is excellent.

• Journal of Hydrogen and New Energy
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• v.32 no.6
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• pp.636-641
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• 2021

Using numerical analysis, various factors influencing the performance development of high-pressure pumps for Dimethyl Ether (DME) engines were identified and the impact of each factor was evaluated using Taguchi method. DME fuels are more compressive than diesel fuels and have the lower heat generation, so it is necessary to increase the size of the plunger and speed (RPM) of the pump as well. In addition, it is necessary to change the shape and design of control valve to control the discharge flow and pressure. In this study, various variables affecting the performance and flow rate increase of high-pressure pumps for DME engines are planned using Taguchi method, and the best design method is proposed using correlation of the most important variables. As a result, we were able to provide the design value needed for a six-liter engine and provide optimal conditions. The best combination factors to optimize the flow rate at RPM 2,000 and diameter plunger with 20 mm. The regression equation can also be used to optimize the flow rate; -8, 13+0, 2552 RPM +54, 17 diam. Plunger.