• Proceedings of the Materials Research Society of Korea Conference
• /
• 2012.05a
• /
• pp.58.2-58.2
• /
• 2012

Heavy hydrocarbon reforming is a core technology for "Dirty energy smart". Heavy hydrocarbons are components of fossil fuels, biomass, coke oven gas and etc. Heavy hydrocarbon reforming converts the fuels into $H_2$-rich syngas. And then $H_2$-rich syngas is used for the production of electricity, synthetic fuels and petrochemicals. Energy can be used efficiently and obtained from various sources by using $H_2$-rich syngas from heavy hydrocarbon reforming. Especially, the key point of "Dirty energy smart" is using "dirty fuel" which is wasted in an inefficient way. New energy conversion laboratory of KAIST has been researched diesel reforming for solid oxide fuel cell (SOFC) as a part of "Dirty energy smart". Diesel is heavy hydrocarbon fuels which has higher carbon number than natural gas, kerosene and gasoline. Diesel reforming has difficulties due to the evaporation of fuels and coke formation. Nevertheless, diesel reforming technology is directly applied to "Dirty fuel" because diesel has the similar chemical properties with "Dirty fuel". On the other hand, SOFC has advantages on high efficiency and wasted heat recovery. Nippon oil Co. of Japan recently commercializes 700We class SOFC system using city gas. Considering the market situation, the development of diesel reformer has a great ripple effect. SOFC system can be applied to auxiliary power unit and distributed power generation. In addition, "Dirty energy smart" can be realized by applying diesel reforming technology to "Dirty fuel". As well as material developments, multidirectional approaches are required to reform heavy hydrocarbon fuels and use $H_2$-rich gas in SOFC. Gd doped ceria (CGO, $Ce_{1-x}Gd_xO_{2-y}$) has been researched for not only electrolyte materials but also catalysts supports. In addition, catalysts infiltrated electrode over porous $La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.2}O_3-{\delta}$ and catalyst deposition at three phase boundary are being investigated to improve the performance of SOFC. On the other hand, nozzle for diesel atomization and post-reforming for light-hydrocarbons removal are examples of solving material problems in multidirectional approaches. Likewise, multidirectional approaches are necessary to realize "Dirty energy smart" like reforming "Dirty fuel" for SOFC.

• Journal of the Korean Institute of Gas
• /
• v.12 no.3
• /
• pp.13-19
• /
• 2008

Among the various prime movers for combined heat and power (CHP) system, the CNG engine is the most commonly used power generation equipment of which power is less than 1MW. The 300 kW class CNG engine for CHP can meet stringent emission regulations with the adoption of stoichiometric air-fuel ratio control and three way catalyst. As the thermal efficiency of the stoichiometric ratio engine is lower than that of lean burn engine, it is necessary to operate the stoichiometric engine at its minimum spark advance for the best torque (MBT). However, knock control should be introduced for the engine under high intake air temperature conditions because MBT operating conditions are generally very close to those of knock occurrence. In this study, engine performances and knocking characteristics were experimentally investigated for the CNG engine that needs to be operated at higher intake air temperature conditions than normal conditions.

• Applied Chemistry for Engineering
• /
• v.7 no.5
• /
• pp.888-901
• /
• 1996

Oxidations of cyclopentene and of 1-pentene with air have been studied on a V/Mo/P/Al/Ti-mixed oxide catalyst in a fixed bed integral reactor. At high levels of conversion maleic anhydride was in each case produced as the major organic product, along with minor amounts of phthalic anhydride and, only starting from 1-pentene, also of citraconic anhydride. At lower levels of conversion a total of 30 organic products have been identified, some of which may be intermediates on the way from the substrates to the three anhydrides mentioned above. Based on the dependence of selectivities of the organic products on conversion, reaction schemes for the formation of maleic anhydride, phthalic anhydride and citraconic anhydride have been proposed. Oxidation at $310^{\circ}C$ led to increasing conversions and selectivities for maleic anhydride with decreasing space velocities. The highest selectivities for maleic anhydride were obtained at conversion of ca. 100%. Oxidation at a constant space velocity of $2{\cdot}10^4h^{-1}$ led to increasing conversions with increasing temperatures in the range of $300^{\circ}C{\sim}420^{\circ}C$, while the selectivity for maleic anhydride passed through a maximum value of ca. 39% at $370^{\circ}C$ in the oxidation of cyclopentene and a maximum value of ca. 30% at $400^{\circ}C$ in the oxidation of 1-pentene.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.6
• /
• pp.309-312
• /
• 2017

The ceria powder is excellent in oxygen storage capacity (OSC) through the oxidation and reduction reaction of Ce ions and is used as a typical material for a three-way catalyst of an automobile which purifies the exhaust gas. However, since ceria generally has poor thermal stability at high temperatures, it is doped with metal ions to improve thermal stability. Therefore, in this study, Zr ions were doped into ceria powder, and their characteristics were further improved due to the increase of specific surface area with decreasing particle size due to doping. In this study, the synthesis of zirconium doped ceria nanopowder was synthesized by hydrothermal process. In order to synthesis Zr ion doped ceria nanopowder, the precursor reaction at was $200^{\circ}C$ for 6 hours. The average particle size of synthesized Zr doped $CeO_2$ nanopowder was below 20 nm. The specific surface area of synthesized Zr ion doped ceria nanopowder increased from $52.03m^2/g$ to $132.27m^2/g$ with Zr increased 30 %.

• Quality Improvement in Health Care
• /
• v.28 no.1
• /
• pp.14-33
• /
• 2022

Purpose: To examine whether the Patient Experience Assessment (PEA) has led to perceptible changes at the ground level of health care, as a way of evaluating PEA as a policy intervention for quality improvement. Methods: Four focus group discussions (FGDs) were conducted, each comprising six to eight participants who were employees responsible for patient experience at their respective hospitals. The primary focus of the FGDs was on questions such as: 1) How do hospitals respond to PEA? 2) What significant changes were observed after the implementation of PEA? 3) What were the unintended consequences of implementing PEA, if any? 4) What areas of improvement have been identified for maximizing the potential of PEA? Results: Two broad themes emerged out of the FGDs: changes observed post implementation of PEA, and areas for improvement of PEA. Four significant changes were reported by participants: changes in perception and attitude regarding patient experience in hospital employees, increased active involvement by the hospital leadership, enhanced efforts to improve patient experience, and increased cooperation between such activities. Furthermore, eight areas of improvement were identified, which have been grouped in three categories: improving the process of data collection for PEA, introducing additional catalysts to facilitate further changes, and paying attention to structure- and patient-level constraints that must be addressed in parallel. Conclusion: The implementation of PEA led to perceptible changes within hospitals, which implies that it can serve as an effective catalyst for improving patient experience. A number of areas of improvement that would aid in maximizing the potential of PEA were also identified.

• Korean Chemical Engineering Research
• /
• v.49 no.4
• /
• pp.491-497
• /
• 2011

In this work, we proposed the three different reactor systems for evaluating of synthetic natural gas(SNG) processes using the synthesis gas consisting of CO and $H_2$ and reactor systems to be considered are series adiabatic reaction system, series adiabatic reaction system with the recirculation and cooling wall type reaction system. The maximum temperature of the first adiabatic reactor in series adiabatic reaction system raised to 800. From the these results, carbon dioxide in product gas as compared to other systems was increased more than that expected due to water gas shift reaction(WGSR) and the maximum $CH_4$ concentration in SNG was 90.1%. In series adiabatic reaction system with the recirculation as a way to decrease the temperature in catalyst bed, the maximum $CH_4$ concentration in SNG was 96.3%. In cooling wall type reaction system, the reaction heat is absorbed by boiling water in the shell and the reaction temperature is controlled by controlling the amount of flow rate and pressure of feed water. The maximum $CH_4$ concentration in SNG for cooling wall type reaction system was 97.9%. The main advantage of the cooling wall type reaction system over adiabatic systems is that potentially it can be achieve almost complete methanation in one reactor.