• New & Renewable Energy
• /
• v.20 no.1
• /
• pp.126-134
• /
• 2024

Biogas, composed mainly of methane (CH₄) and carbon dioxide (CO₂), is a renewable gas that can serve as an alternative energy source. In this study, we developed a new microwave reformer and analyzed its reforming characteristics. We observed that higher temperatures of the microwave receptor led to increased reforming efficiency. By supplying appropriate amounts of methane and steam, we could prevent carbon generated from the thermal decomposition reaction of carbon dioxide from depositing on the catalytic active layer, thus avoiding the inhibition of catalytic activity. Hydrogen generation was enhanced when maintaining the biogas ratio and steam supply at adequate levels. Increasing the SiC ratio in the receptor improved the uniformity of temperature distribution and growth rate, resulting in higher conversion rates of the reforming process.

• Korean Chemical Engineering Research
• /
• v.47 no.6
• /
• pp.700-704
• /
• 2009

A simulation study on SCR(steam carbon dioxide reforming) in gas-to-liquid(natural gas to Fischer-Tropsch synthetic fuel) process was carried out in order to find optimum reaction conditions for SCR experiment. Optimum operating conditions for SCR process were determined by changing reaction variables such as temperature and $CH_4/steam/CO_2$ feed ratio. Simulation was carried out by Aspen Plus. During the simulation, overall process was assumed to proceed under steady-state conditions. It was also assumed that physical properties of reaction medium were governed by RKS(Redlich-Kwong-Soave) equation. Optimum simulation variables such as temperature and feed ratio were determined by considering $H_2/CO$ ratio for FTS(Fischer-Tropsch synthesis), $CH_4$ conversion, and $CO_2$ conversion. Simulation results showed that optimum reaction temperature and $CH_4/steam/CO_2$ feed ratio in SCR process were $850^{\circ}C$ and 1.0/1.6/0.7, respectively. Under optimum temperature of $850^{\circ}C$, $CH_4$ conversion and $CO_2$ conversion were found to be 99% and 49%, respectively.

• Transactions of the Korean hydrogen and new energy society
• /
• v.15 no.4
• /
• pp.301-308
• /
• 2004

The methane reforming with $CO_2$ and steam for manufacture of synthesis gas over $Ni/ZrO_2$ catalyst was investigated. Mixed reforming carried out $CO_2$ dry reforming with $O_2$ and steam for development of DME process in pilot plant. To improve a catalyst deactivation by coke formation, the mixed reforming added carbon dioxide and steam as a oxidizer of the methane reforming was suggested. The result of experiments over commercial catalyst in $CO_2$ dry reforming has shown that the catalyst activity decrease rapidly after 20 hours. In case of $NiO-MgO/Al_2O_3$ catalyst, the deactivation of 20 percent after 30 hours was occurred. The activity of Ni/C catalyst still was not decreased dramatically after 100 hours. The effect of $H_2$ reforming with steam over $Ni/CO_2$ catalyst obtained the optimal conversion of methane and carbon dioxide, and could be produced synthesis gas at ratio of $H_2/CO$ under 1.5.

• Journal of the Korean Chemical Society
• /
• v.15 no.2
• /
• pp.55-63
• /
• 1971

In this study, several nickel catalysts for the steam-hydrocarbon reforming process were prepared from various nickel salt, magnesium oxide, alumina and kaolinite. The activity and strength of the catalysts were investigated. 1. The proper composition of the calcined catalysts are: NiO (5-15%)-MgO(10-20%)-$Al_2O_3$(10-40%)-Kaolinite(50-80%). 2. The admixed or cosedimented ingredients of the catalysts was pelletized and calcinated at 1000 or $1150^{\circ}C$. Calcination at $1150^{\circ}C$ for an hour was optimum. 3. The water to oil ratio (W/O) for reforming of hexane should be above 7 mole/mole. As the W/O increases, more carbon dioxide and hydrogen, but less carbon monoxide was produced. Also carbon deposition become lessen at higher W/O. 4. Maximum conversion had attained at about $850^{\circ}C$. As the reaction temperature increases, more carbon monoxide and hydrogen, but less carbon dioxide and lower hydrocarbon was produced. 5. The percent conversion at $850^{\circ}C$ was about 80%, using a catalyst which the nickel oxide content are 5%.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.247-250
• /
• 2008

Biomass gasification is a promising technology for producing a fuel gas which is useful for power generation systems. In biomass gasification processes, tar formation often causes some problems such as pipeline plugging. Thus, proper tar treatment is necessary. So far, nickel (Ni)-based catalysts have been intensively studied for the catalytic tar removal. However, the deactivation of Ni-based catalysts takes place because of coke deposition and sintering of Ni metal particles. To overcome these problems, we have been using ruthenium (Ru)-based catalyst for tar removal. It is reported by Okada et al., that a Ru/$Al_2O_3$ catalyst is very effective for preventing the carbon deposition during the steam reforming of hydrocarbons. Also, this catalyst is more active than the Ni-based catalyst at a low steam to carbon ratio (S/C). Benzene was used for the tar model compound because it is the main constituent of biomass tar and also because it represents a stable aromatic structure apparent in tar formed in biomass gasification processes. The steam reforming process transforms hydrocarbons into gaseous mixtures constituted of carbon dioxide ($CO_2$), carbon monoxide (CO), methane ($CH_4$) and hydrogen ($H_2$).

• Korean Chemical Engineering Research
• /
• v.52 no.6
• /
• pp.727-735
• /
• 2014

For improved sustainability of the biorefinery industry, biorefinery-byproduct glycerol is being investigated as an alternate source for hydrogen production. This research designs and optimizes a hydrogen-production process for small hydrogen stations using steam reforming of purified glycerol as the main reaction, replacing existing processes relying on steam methane reforming. Modeling, simulation and optimization using a commercial process simulator are performed for the proposed hydrogen production process from glycerol. The mixture of glycerol and steam are used for making syngas in the reforming process. Then hydrogen are produced from carbon monoxide and steam through the water-gas shift reaction. Finally, hydrogen is separated from carbon dioxide using PSA. This study shows higher yield than former U.S. DOE and Linde studies. Economic evaluations are performed for optimal planning of constructing domestic hydrogen energy infrastructure based on the proposed glycerol-based hydrogen station.

• Transactions of the Korean hydrogen and new energy society
• /
• v.30 no.2
• /
• pp.111-118
• /
• 2019

Greenhouse gas emissions have a profound effect on global warming. Various environmental regulations have been introduced to reduce the emissions. The largest amount of greenhouse gases, including carbon dioxide, is produced in the steel industry. To decrease carbon dioxide emission, hydrogen-based iron oxide reduction, which can replace carbon-based reduction has received a great attention. Iron production generates various by-product gases, such as cokes oven gas (COG), blast furnace gas (BFG), and Linz-Donawitz gas (LDG). In particular, COG, due to its high concentrations of hydrogen and methane, can be reformed to become a major source of hydrogen for reducing iron oxide. Nevertheless, continuous COG cannot be supplied under actual operation condition of steel industry. To solve this problem, this study proposed to use two alternative COG-based fuel mixtures; one with natural gas and the other with biogas. Reforming study on two types of mixed gas were carried out to evaluate catalyst performance under a variety of operating conditions. In addition, methane conversion and product composition were investigated both theoretically and experimentally.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.731-734
• /
• 2009

KIER has been developed a compact and highly efficient fuel processor which is one of the key component of the residential PEM fuel cells system. The fuel processor uses methane steam reforming to convert natural gas to a mixture of water, hydrogen, carbon dioxide, carbon monoxide and unreacted methane. Then carbon monoxide is converted to carbon dioxide in water-gas-shift reactor and preferential oxidation reactor. A start-up time of the fuel processor is about 1h and CO concentration among the final product is maintained less than 5 vol. ppm. To achieve high thermal efficiency of 80% on a LHV basis, an optimal thermal network was designed. Internal heat exchange of the fuel processor is so efficient that the temperature of the reformed gas and the flue gas at the exit of the fuel processor remains less than $100^{\circ}C$. A compact design considering a mixing and distribution of the feed was applied to reduce the reactor volume. The current volume of the fuel processor is 17L with insulation.

• Applied Chemistry for Engineering
• /
• v.31 no.1
• /
• pp.1-6
• /
• 2020

Hydrogen production from biogas has received consistent attention due to the great potential to solve simultaneously the issues of energy demands and environmental problems. Practically, biomethane produced by purification/upgrading of biogas can be a good alternative to the natural gas which is a main reactant for a steam methane reforming process. Judging from the economic and environmental impacts, however, the steam biogas and dry reforming are considered to be more effective routes for hydrogen production because both processes do not require the carbon dioxide elimination step. Herein, we highlight recent studies of hydrogen production via reforming processes using biogas and effective applications for earlier commercialization.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.10a
• /
• pp.615-616
• /
• 2006

A micro-fuel processor system integrating steam reformer and partial oxidation reactor was manufactured using low temperature cofired ceramic (LTCC). A CuO/ZnO/$Al_2O_3$ catalyst and Pt-based catalyst prepared by wet impregnation were used for steam reforming and partial oxidation, respectively. The performance of the LTCC micro-fuel processor was measured at various operating conditions such as the effect of the feed flow rate, the ratio of $H_2O/CH_3OH$, and the operating temperature on the LTCC reformer and CO clean-up system. The catalyst layer was loaded with "Fill and Dry" coating for small volume. The product gas was composed of $70\sim75%$ hydrogen, $20\sim25%$ carbon dioxide, and $1\sim2%$ carbon monoxide at $250\sim300^{\circ}C$, respectively.