• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2753-2760
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• 2021

This paper proposes using sodium-cooled fast reactor technologies for use in hydrogen vapor methane (SMR) modification. Using three independent energy rings in the Russian BN-600 fast reactor, steam is generated in one of the steam-generating cycles with a pressure of 13.1 MPa and a temperature of 505 ℃. The reactor's second energy cycles can increase the gas-steam mixture's temperature to the required amount for efficient correction. The 620 ton/hr 540 ℃ steam generated in this cycle is sufficient to supply a high-temperature synthesis current source (700 ℃), which raises the steam-gas mixture's temperature in the reactor. The proposed technology provides a high rate of hydrogen production (approximately 144.5 ton/hr of standard H₂), also up to 25% of the original natural gas, in line with existing SMR technology for preparing and heating steam and gas mixtures will be saved. Also, exergy analysis results show that the plant's efficiency reaches 78.5% using HTR heat for combined hydrogen and power generation.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.6
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• pp.519-525
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• 2009

The catalytic steam reforming of woody biomass tar and soot to convert a synthetic gas containing hydrogen was investigated by using a bench-scale biomass gasification system. One commercial nickel-based catalyst, Katalco 46-6Q, and two different kinds of natural minerals, dolomite and olivine, were tested as a reforming catalyst at various reforming temperatures. The reaction characteristics of woody biomass tar were also investigated by TGA at a variety of heating rates. With all three catalysts conversion efficiency of tar and soot increased at increasing temperature. The reforming of tar and soot in the synthetic gas induce the increase of combustible gases such as $H_2$, CO and $CH_4$ in the product gas. The nickel-based catalyst showed a higher tar and soot conversion efficiency than mineral catalysts under the same temperature conditions.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.601-607
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• 2019

Ammonia would be formed in natural gas containing small amount of nitrogen reforming process in the process natural gas, which might damage the Pt catalyst and Prox catalyst. In the article, the effect of nitrogen contents on the formation of ammonia in the reforming process has been studied. In the experiments, Ru based and Ni based catalysts were used and the concentration of ammonia in the reformate gas at various gas hourly space velocity was measured. Experimental result shows that relatively higher ammonia concentration was measured with Ru based catalyst than with Ni based catalyst. It also shows that the concentration of ammonia increased rapidly after most of the methane converted into hydrogen. Based on the experimental results to reduce ammonia concentration it might be better to finish methane conversion at the exit position of the reforming reactor to minimize the contact time of catalyst and nitrogen with high concentration of hydrogen.

• Journal of the Korean Ceramic Society
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• v.53 no.5
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• pp.483-488
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• 2016

Anode supported solid oxide fuel cells (SOFCs), consisting of Ni+YSZ anode, YSZ electrolyte, and LSM+YSZ cathode, were fabricated and constant current tested with direct internal reforming of methane (steam to carbon ratio ~ 2) as well as hydrogen fuel at $800^{\circ}C$. The cell, operated under direct internal reforming conditions, showed relatively rapid degradation (~ 1.6 % voltage drop) for 95 h; the cells with hydrogen fuel operated stably for 170 h. Power density and impedance spectra were also measured before and after the tests, and post-test analyses were conducted on the anode parts using SEM / EDS. The results indicate that the performance degradation of the cell operated with internal reforming can be attributed to carbon depositions on the anode, which increase the resistance against anode gas transport and deactivate the Ni catalyst. Thus, the present study shows that direct internal reforming SOFCs cannot be stably operated even under the condition of S/C ratio of ~ 2, probably due to non-uniform mixture (methane and steam) gas flow.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.3
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• pp.149-155
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• 2021

Most of the reformer experiments have been conducted only in high-temperature operation conditions above 700℃. However, to design high efficiency solid oxide fuel cell, it is necessary to test actual reaction performance in mid-temperature (550℃) operation areas. In order to study the operation characteristics and performance of commercial reforming catalysts, a reforming performance experiment was conducted on mid-temperature. The catalysts used in this study are Ni-based FCR-4 and Ru-based RuA, RuAL. Experiments were conducted with a Steam-to-carbon ratio of 2.0 to 3.0 under gas hourly space velocity (GHSV) 2,000 to 5,000 hr-1. As a result, RuA and RuAL catalysts showed similar gas composition to the equilibrium regardless of the reforming temperature. However, the FCR-4 catalyst showed a lower hydrogen yield compared to the equilibrium under high GHSV conditions.

• Clean Technology
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• v.29 no.3
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• pp.163-171
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• 2023

Hydrogen has been gaining a lot of attention as a possible clean energy source that can aid in reaching carbon neutrality. Currently, hydrogen production has relied on the steam reforming of fossil fuels. However, due to the carbon dioxide emissions caused by this process, hydrogen production based on the steam reforming of bio-oil derived from biomass has been proposed as an alternative approach. In order to use this alternative approach efficiently, one of the key issues that must be overcome is that the complexity of bio-oil, which has a large molecular weight and diverse functional groups of hydrocarbons, promotes the catalytic deactivation of nickel-based catalysts. In this review, research efforts to improve nickel-based catalysts for the steam reforming of bio-oil have been discussed in terms of the active phase, support, and promoters. The active phases are involved in activating C-C and C-H bonds of high-molecular-weight hydrocarbons, and noble and transition metals can be utilized. In terms of the support and promoters, the catalytic deactivation of Ni-based catalysts can be inhibited by utilizing reactive lattice oxygen for support or by suppressing the acidity. The development of active and stable Ni-based reforming catalysts plays a critical role in clean hydrogen production based on bio-oils.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.1
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• pp.81-93
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• 2015

Steam Reforming H2 Generation (SRH2G) System is a chemical process to produce hydrogen through steam reforming of hydrocarbon. Largely speaking, there are two types of materials for the SRH2G: 1) Oil and coal, and 2)Natural Gas such as shale gas. From the perspective of cost, quality (purity), and environmental burden (pollution), the latter is much more desirable than the former. For this reason, research on SRH2G using natural gas is actively carried out, and implemented and operated in the various industry. In this paper, we develop a natural gas based SRH2G system via systems engineering approach. Specifically, we first derived stakeholder requirements, followed by systems requirements and finally system architecture via a tailored SE process for plant (called Plant Systems Engineering (PSE) process) based on ISO/IEC 15288. The developed method was applied to iron and steel plant as a case study. Through the case study, by the SE approach, we were convinced that a successful system satisfying stakeholders' requirements within the given constraints can be developed, verified and validated.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.95-101
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• 2016

For a natural gas steam reforming, comparative studies of the performance in a conventional packed-bed reactor and a membrane reactor, a new conceptual reactor consisting of a reactor with series of hydrogen separation membranes, have been performed. Based on experimental kinetics reported by Xu and Froment, a process simulation model was developed with Aspen $HYSYS^{(R)}$, a commercial process simulator, and effects of various operating conditions like temperature, $H_2$ permeance, and Ar sweep gas flow rate on the performance in a membrane reactor were investigated in terms of reactant conversion and $H_2$ yield enhancement showing improved $H_2$ yield and methane conversion in a membrane reactor. In addition, a preliminary cost estimation focusing on natural gas consumption to supply heat required for the system was carried out and feasibility of possible cost savings in a membrane reactor was assessed with a cost saving of 10.94% in a membrane reactor.

• Clean Technology
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• v.15 no.2
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• pp.130-136
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• 2009

Commercial catalyst (Cu-Zn/$Al_2O_3$, Johnson Matthey Co., 83-3 Catalyst) was applied to the hydrogen production by steam reforming of methanol in the micro-channel reactor (MCR). The steam reforming of methanol was tested over Cu-Zn catalyst at temperatures in the range of 200 and 300$^{\circ}C$, the catalyst size of 0.05${\sim}$2.2 mm, the space velocity of 3,000${\sim}$10,000 $hr^{-1}$ in a fixed bed continuous flow reactor. The conversion of methanol and the yield $H_2$ preferred high temperatures and low space velocities, and had optimal results with the particle size of 0.35 mm. Based on the results from experiments with fixed bed reactor, two types of MCR, boat bed and stacked bed MCRs, were studied. The stacked bed type MCR showed better methanol conversion compared with the boat type one.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.581-586
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• 2023

As the development of alternative energy is required due to the depletion of fossil fuels, interest in the use of hydrogen energy is increasing. Hydrogen is a promising clean energy source with high energy density and can lead to the application of environmentally friendly technologies. However, due to difficulties in production, storage, and transportation that prevent the application of hydrogen-based eco-friendly technology, research on reforming reactions using dimethyl ether (DME) is being conducted. Unlike other hydrocarbons, DME is attracting attention as a hydrogen carrier because it has excellent storage stability and transportability, and there is no C-C bond in the molecule. The reaction between DME and steam is one of the reforming processes with the highest hydrogen yield in theory at a temperature lower than that of other hydrocarbons. In this study, a hydrogen reforming device using DME was developed and a catalyst prepared by supporting Cu in alumina was put into a reactor to find optimal hydrogen production conditions for supplying hydrogen to fuel cells while changing reaction temperature (300-500℃), pressure (5-10 bar), and steam/carbon ratio (3:1 to 5:1).