• 한국연소학회:학술대회논문집
• /
• 2013.06a
• /
• pp.55-58
• /
• 2013

A new soot particle generation system has been developed and tested. The soot generation system consists of two sections, a fuel supply and a soot production. In the fuel supply module, either liquid fuel precisely controlled by a syringe pump is mixed with preheated carrier gas and rapidly evaporated or gaseous fuel controlled by a MFC is diluted with dilution gas. The soot production module contains a heater that can raise the gas/fuel temperature up to $1400^{\circ}C$. The physical and chemical properties of produced soot particles depend on the type and concentration of fuel, the residence time, and temperature in the soot production section. The soot generation system will be utilized to produce well-defined soot particles for soot studies such as the evaluation of experimental sampling and analysis processes for the quantitative assessment of PM and BC from ships and the adverse health effects on pulmonary and cardiovascular systems of human body.

• Journal of Electrochemical Science and Technology
• /
• v.13 no.1
• /
• pp.63-70
• /
• 2022

Compared with hydrogen, ammonia has the advantages of high gravimetric hydrogen densities (17.8 wt.%), ease of storage and transportation as a chemical hydrogen storage medium, while its application in small-scale on-site hydrogen production scenarios is limited by the need for complex separation equipment during high purity hydrogen production. Therefore, the study of PEMFC, which can directly utilize ammonia decomposition gas, can greatly expand the application of fuel cells. In this paper, the output characteristics, fuel efficiency and the variation trend of hydrogen concentration and local current density in the anode channel of fuel cell with the output voltage of PEMFC fueled by ammonia decomposition gas were studied by experiment and simulation. The results indicate that the maximum output power of the hybrid fuel decreases by 9.6% compared with that of the pure hydrogen fuel at the same inlet hydrogen equivalent. When the molar concentration of hydrogen in the anode channel is less than 0.12, the output characteristics of PEMFC will be seriously affected. Employing ammonia decomposition gas as fuel, the efficiency corresponding to the maximum output power of PEMFC is approximately 47%, which is 10% lower than the maximum efficiency of pure hydrogen.

• Applied Chemistry for Engineering
• /
• v.34 no.3
• /
• pp.291-298
• /
• 2023

This research evaluates the sustainability of gasifying livestock manure to produce fuel gas from an economic and carbon emission perspective. The entire process, including gasification, fuel gas purification, and pipeline installation to transport the produced fuel gas to the demanding industrial complex, is analyzed for realistic feasibility. The study is conducted using an ASPEN PLUS simulation with experimental data. The results of the economic and CO₂ life cycle assessments confirm that the fuel gas produced from livestock manure is competitive with natural gas despite having a lower calorific value. When used as a fuel with a high hydrogen content, the fuel gas emits less CO₂ per calorific value, making it more environmentally friendly. A scenario analysis is also performed to determine the expected economics, with price competitiveness being influenced by several factors. Although a significant decrease in natural gas prices could reduce the price competitiveness of the proposed process, it can still be supported by government policies. The cash flow analysis also confirms the economic viability of the process.

• Korean Chemical Engineering Research
• /
• v.43 no.3
• /
• pp.344-351
• /
• 2005

Hydrogen energy will be considered one of the most important energy carries for the future not only as raw material of petroleum chemical industry but also as the fuel of the fuel cell. The hydrogen production based upon the water electrolysis system combined renewable energy or atomic power energy is being watched as long-term hydrogen sources. Hydrogen from fossil fuel, especially natural gas steam reforming, is the economical mass production method at this time. But the cost of $CO_2$ reduction is added in the economic analysis of hydrogen production processes. Therefore many different results are suggested from these analyses about old processes, and modified schemes are studying for the efficient development. In this review, status for the technology of hydrogen production from natural gas are summarized.

• Journal of Hydrogen and New Energy
• /
• v.15 no.2
• /
• pp.119-128
• /
• 2004

DME(Dimethyl Ether) was directly produced from the synthesis gas using the slurry phase reactor. The catalyst for DME production prepared two types (A type; Cu:Zn:Al=57:33:10, B type; Cu:Zn:Al=40:45:15, molar ratio). It was evaluated for the effect of the reaction medium oil using the small size slurry phase reactor. DME production yield and the methanol selectivity decreased in the order: n-hexadecane oil> mineral oil> therminol oil. The long-term test of DME production was carried out using A and B type catalyst, and n-hexadecane oil and mineral oil, respectively. It was confirmed that the use of A type for the catalyst and n-hexadecane for the reaction medium oil was very useful for the viewpoint of the DME production form the synthesis gas.

• Advances in Energy Research
• /
• v.1 no.1
• /
• pp.53-78
• /
• 2013

Methane carbon dioxide reforming (MCDR) is a promising way of utilizing greenhouse gas for hydrogen-rich fuel production. Compared with other types of reactors, Compact Reformers (CRs) are efficient for fuel processing. In a CR, a thin solid plate is placed between two porous catalyst layers to enable efficient heat transfer between the two catalyst layers. In this study, the physical and chemical processes of MCDR in a CR are studied numerically with a 2D numerical model. The model considers the multi-component gas transport and heat transfer in the fuel channel and the porous catalyst layer, and the MCDR reaction kinetics in the catalyst layer. The finite volume method (FVM) is used for discretizing the governing equations. The SIMPLEC algorithm is used to couple the pressure and the velocity. Parametrical simulations are conducted to analyze in detail the effects of various operating/structural parameters on the fuel processing behavior.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.11a
• /
• pp.184-187
• /
• 2007

Hydrogen could be produced from any substance containing hydrogen atoms, such as water, hydrocarbon (HC) fuels, acids or bases. Hydrocarbon fuels couold be converted to hydrogen-rich gas through reforming process for hydrogen production. Even though fuel cell have high efficiency with pure hydrogen from gas tank, it is more beneficial to generate hydrogen from city gas (mainly methane) in residential application such as domestic or office environments. Thus hydrogen is generated by reforming process using hydrocarbon. Unfortunately, the reforming process for hydrogen production is accompanied with unavoidable impurities. Impurities such as CO, $CO_2$, $H_2S$, $NH_3$, and $CH_4$ in hydrogen could cause negative effects on fuel cell performance. Those effects are kinetic losses due to poisoning of electrode catalysts, ohmic losses due to proton conductivity reduction including membrane and catalyst ionomer layers, and mass transport losses due to degrading catalyst layer structure and hydrophobic property. Hydrogen produced from reformer eventually contains around 73% of $H_2$, 20% or less of $CO_2$, 5.8% of less of $N_2$, or 2% less of $CH_4$, and 10ppm or less of CO. Most impurities are removed using pressure swing adsorption (PSA) process to get high purity hydrogen. However, high purity hydrogen production requires high operation cost of reforming process. The effect of carbon dioxide on fuel cell performance was investigated in this experiment. The performance of PEM fuel cell was investigated using current vs. potential experiment, long run (10 hr) test, and electrochemical impedance measurement when the concentrations of carbon dioxide were 10%, 20% and 30%. Also, the concentration of impurity supplied to the fuel cell was verified by gas chromatography (GC).

• Journal of Mechanical Science and Technology
• /
• v.19 no.6
• /
• pp.1358-1365
• /
• 2005

Flue gas recirculation (FGR) is widely adopted to control NO emission in combustion systems. Recirculated flue gas decreases flame temperature and reaction rate, resulting in the decrease in thermal NO production. Recently, it has been demonstrated that the recirculated flue gas in fuel stream, that is, the fuel induced recirculation (FIR), could enhance much improved reduction in NO per unit mass of recirculated gas, as compared to conventional FGR in air. In the present study, the effect of dilution methods in air and fuel sides on NO reduction has been investigated numerically by using $N_2$ and $CO_2$ as diluent gases to simulate flue gases. Counterflow diffusion flames were studied in conjunction with the laminar flamelet model of turbulent flames. Results showed that $CO_2$ dilution was more effective in NO reduction because of large temperature drop due to the larger specific heat of $CO_2$ compared to $N_2$. Fuel dilution was more effective in reducing NO emission than air dilution when the same recirculation ratio of dilution gas was used by the increase in the nozzle exit velocity, thereby the stretch rate, with dilution gas added to fuel side.

• 한국가스학회:학술대회논문집
• /
• 2005.10a
• /
• pp.141-145
• /
• 2005

DME (Di-Methyl Ether) is a new clean fuel and an environmental-friendly energy resource, also is recently increasing with an alternative interest because of the industrial use. DME has been shown to have excellent properties as a diesel fuel giving emission level better than ULEV standard. So it has been attracting considerable as an alternative diesel fuel. In this study, we carried out simulation of separation and purification process of demo plant for 101on per day DME production, which cause the effect that is important in productivity, from operation results of pilot plant for 50kg per day DME production. The liquefied stream, which was separated by gas-liquid separator after DME reactor, includes $CO_2$, DME, Methanol and $H_2O$. We established three distillation columns for separation and purification of the stream. $CO_2$ was extracted from the stream by first distillation column, DME was extracted by second column and Methanol was extracted by third column. We investigated and analyzed the effect which the actual operation variables cause in efficiency of process and optimized process, finally we got the DME of purity $100\%$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.717-720
• /
• 2011

Due to the depletion of fossil fuel, high oil price and global warming issue by green house gas such as CO2, clean synthetic fuel technologies using biomass, especially GTL(Gas To Liquid) technology, have been greatly attracted. This paper has examined and compared the worldwide technologies trend of natural gas reforming reaction, F-T(Fisher-Tropsch) synthesis and upgrading process which are three backbones of GTL technology.