• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.209-219
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• 2019

Methanol is a liquid fuel which could also be produced from renewable energy sources and has appreciably high energy density. In this work, we investigated the application of $Ce_{0.9}Gd_{0.1}O_{2-x}$ supported Cu and Ni catalysts for hydrogen production via methanol steam reforming. Catalysts were synthesized by solution combustion synthesis. The prepared catalysts with various active materials and Cu loading amounts were tested in a reactor at $200-300^{\circ}C$, 0-5 barg range and steam to methanol molar ratio was 1.5. The catalytic properties of Cu and Ni were compared, and the catalytic performance was shown to depend on the amounts of metal loading and operating conditions such as reaction temperature and pressure.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.328-339
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• 2023

Methanol steam reforming (MSR) is a promising method for hydrogen supplying as a critical step in hydrogen fuel cell commercialization in mobile applications. Modelling and understanding of the reactor behavior is an attractive research field to develop an efficient reformer. Three-layer feed-forward artificial neural network (ANN) and Box-Behnken design (BBD) were used to modelling of MSR process using the Cu-SiO₂ aerogel catalyst. Furthermore, impacts of the basic operational variables and their mutual interactions were studied. The results showed that the most affecting parameters were the reaction temperature (56%) and its quadratic term (20.5%). In addition, it was also found that the interaction between temperature and Steam/Methanol ratio is important on the MSR performance. These models precisely predict MSR performance and have great agreement with experimental results. However, on the basis of statistical criteria the ANN technique showed the greater modelling ability as compared with statistical BBD approach.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.589-593
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• 2018

In this paper, an economic evaluation with the uncertainty analysis using a Monte-Carlo simulation method was performed for the glycerol steam reforming to produce $H_2$ at a capacity of $300m^3h^{-1}$. Fluctuations in a unit $H_2$ production cost were identified based on the variation of key economic factors at ${\pm}10-{\pm}40%$ and the probability of 30.9% was obtained for a previously reported unit $H_2$ production cost of 5.10 $ $kgH{_2}^{-1}$. In addition, fluctuations in the B/C ratio were obtained by varying the fixed capital investment (${\pm}20%$), cost of manufacturing (${\pm}20%$), revenue (${\pm}20%$), and discount rate (2-10%) and the probability ranging from 17 to 55% was observed to meet a minimum B/C ratio of 1 for the economic feasibility of the glycerol steam reforming to produce $H_2$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.135-144
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• 2021

In this study, we investigated the characteristics of the process of hydrogen production using boil-of gas (BOG) generated from an LNG-fueled ship and the application of hydrogen fuel cell systems as auxiliary engines. In this study, the BOG steam reformer process was designed using the UniSim R410 program, and the reformer outlet temperature, pressure, and the fraction and consumption of the product according to the steam/carbon ratio (SCR) were calculated. According to the study, the conversion rate of methane was 100 % when the temperature of the reformer was 890 ℃, and maximum hydrogen production was observed. In addition, the lower the pressure, the higher is the reaction activity. However, higher temperatures have led to a decrease in hydrogen production owing to the preponderance of adverse reactions and increased amounts of water and carbon dioxide. As SCR increased, hydrogen production increased, but the required energy consumption also increased proportionally. Although the hydrogen fraction was the highest when the SCR was 1.8, it was confirmed that the optimal operation range was for SCR to operate at 3 to prevent cocking. In addition, the lower the pressure, the higher is the amount of carbon dioxide generated. Furthermore, 42.5 % of the LNG cold energy based on carbon dioxide generation was required for cooling and liquefaction.

• Journal of the Korean Institute of Gas
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• v.20 no.5
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• pp.27-33
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• 2016

The aim of numerical study is the investigation of the solid and fluid temperatures in a reformer tube and chemical reaction characteristics of different steam-carbon ratio. We considered conjugate heat transfer contain radiation, convection and conductive heat transfers. This is because steam reforming reaction of hydrocarbon occurred high temperature conditions up to 800 K- 1000 K by using commercial computational fluid dynamics (CFD) code (Fluent ver. 13.0). For numerical simulation, the Reynolds-Averaged Navier-Stokes, momentum and energy equation were employed. In addition, inside of reformer tube is assumed as the porous medium to consider the Nichrome-based catalyst. To analysis characteristics of tube temperature in chemical reaction, we changed steam-methane ratio(SCR) from 1 to 6. As increased SCR, the higher tube temperature and methane conversion were observed. It was obtained that the highest hydrogen production held in SCR of 5.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1186-1190
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• 2002

One hundred and twenty nine primiparous sows were used to determine the effects of alternative processing procedures and feeding systems on the nutritional value of sorghum grain-based diets for lactating sows. Treatments were a ground sorghum control, steam-flaked sorghum and extruded sorghum fed in meal form and the ground sorghum control given as pellets or gruel (1:1 ratio of water and feed on a volume:volume basis). Average daily feed intake was greater for sows fed pelleted and gruel diet forms than sow fed the diets with steam-flaked and extruded sorghum (p<0.04). However, no differences occurred in sow weight or backfat losses among the treatments (p>0.14). Number of pigs weaned and livability rates were similar among treatments except that steam-flaked sorghum supported greater litter weight gains than extruded sorghum (p<0.02). Apparent digestibilities of DM, N and GE in sows fed steam-flaked and extruded sorghum were greater (p<0.001) than in sows fed pelleted or gruel diets. Of the various treatments, sows fed extruded sorghum tended to have the highest digestibilities of DM, N and GE, and lowest excretions of DM and N in the faeces. Severity of ulceration was not significantly affected by treatments (p>0.35), but keratinization was greatest for sows fed extruded sorghum (p<0.01). In conclusion, the alternative processing methods (steam-flaking and extrusion) and feeding system (pellets and gruel) had little effect on sow and litter performance. However, nutrient digestibilities were improved for all treatments that involved heating (steam flaking, extrusion and pelleting) and, thus, these treatments resulted in less fecal excretion of DM and N.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.515-520
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• 2007

Recently, the treat of sludge is usually progressed by ocean disposal. But it will be totally banned by content of its heavy metal according to London Dumping Convention, gradually. The stable way of treat of sewage sludge should be examined urgently. To solve the problem, recently, there are efficient and environment-oriented method. One of them is to produce absorbent through the activation. This study produces absorbent through steam activation. As basic experiment, optimum activation condition for preparation of good absorbent is researched through study of the fellowing variables : steam flow rate, activated temperature, activation time. As the result of this with standard on iodine adsorptivity, it is chosen, that steam flow rate "30 mL/hr", activation temperature $"500^{\circ}C"$, activation time "60 minutes". At the time, iodine adsorptivity and yield shown that 228.4 mg/g, 77.23%. And also, by using nitrogen adsorption, SEM and EDS are confirmed that pore development, specific surface area, mean pore size, chemical component and content. Pore developed by steam activation is also confirmed that it is micropore.

• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.660-667
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• 2020

This study focused on the epoxy resin production process, which uses the steam of 155 ℃ or higher as a heat source, and discards all condensate generated. A part of the process is operated at low temperatures of 70 ℃ or below, thus there are opportunities to reduce the steam consumption by recycling wasted condensate as a heat source for the low temperature section of process. In this study, we developed process models that can reduce steam by recovering waste heat through recycling condensate and conducted a case study to find an optimal condensate recycling system. Three different process designs were proposed and economic evaluations were performed by comparing annual capital costs and steam savings in each case. Finally, an annual steam consumption of the low-temperature section could be reduced by up to 67.6%, which could also bring an additional economic benefit of 522.1 million won/yr.

• Journal of the Korean Society of Earth Science Education
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• v.16 no.2
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• pp.247-260
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• 2023

In this study, when applying the 'geological structure' content element of high school earth science I developed according to the 2015 curriculum to the STEAM program using a web-based expert system using 3D data of Google Earth and drones, the creative problem-solving ability of high school students, attitudes toward STEAM, and the results of this study are as follows. First, after applying the STEAM program, high school students' creative problem-solving ability showed meaningful results at the p<.001 level. Second, STEAM attitudes showed a significant value at the p<.001 level, confirming that they had a positive impact on high school students' attitudes towards STEAM. It was judged that web-based class activities using Google Earth and drones were useful for integrated thinking such as learners' sense of efficacy and value recognition for usefulness of knowledge. High school students' satisfaction with the STEAM program was 3.251, showing a slightly high average. It was confirmed that web-based class activities such as drones and Google Earth had a positive impact on learners' class satisfaction. However, it was interpreted that the lack of time for class activities limited the ability of the learners to increase their interest in class. The proposal of this research is as follows. First of all, in consideration of the production of presentation materials and practical training in the STEAM program, activities such as block time and advance instruction for class understanding before class are necessary. Secondly, in order to revitalize STEAM education in the high school curriculum, we judge that research on the development of various integrated education programs that can be applied to the high school grade system is necessary.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.1
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• pp.95-108
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• 2007

There are several methods for the hydrogen production such as steam reforming of natural gas, photocatalytic method, biological method, electrolysis and thermochemical method, etc. These days it has been widely studying for the hydrogen production method having low hydrogen production cost and high efficiency. In this paper, patents in the hydrogen production by water electrolysis were gathered and analyzed. The search range was limited in the open patents of USA(US), European Union(EP), Japan(JP), and Korea(KR) from 1996 to 2005. Patents were gathered by using key-words searching and filtered by filtering criteria. The trends of the patents was analyzed by the years, countries, companies, and technologies.