• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.7-12
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• 2015

Hydrogen is usually produced by using syngas generated by the fuel reforming for natural gas so far. The further process is needed for increasing the hydrogen yield of syngas. However, the process for upgrading the hydrogen yield is accompanied by additional energy sources and economic costs. Thus related studies on the method for using as a mixture in itself have been conducted in order to utilize more efficiently syngas. The effect on the engine performance for methane/syngas mixture of 30kW spark ignition gas engine for power generation has been investigated in this study. As a result, it was found that the combustion phenomena such as the maximum in-cylinder pressure and crank angle at that time have been improved by methane/syngas mixture. Through these, fuel conversion efficiency could be enhanced by about 98% of methane/hydrogen mixture and $NO_x$ emissions could be reduced by about 12% of methane-hydrogen mixture.

• Journal of ILASS-Korea
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• v.24 no.1
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• pp.35-42
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• 2019

Syngas is widely produced by incomplete combustion of coal, water vapor, and air (oxygen) in a high-temperature/high-pressure gasifier through a coal-gasification process for power generation. In this study, a simulation syngas which was mainly composed of $H_2$, CO, $CO_2$, and $N_2$ was fueled with diesel. A modified single cylinder compression ignition (CI) engine is equipped with intake port syngas supply system and mechanical diesel direct injection system for dual fuel combustion. Combustion and emission characteristics of the engine were investigated by applying various syngas composition ratios and compression ratios. Diesel fuel injection timing was optimized to increase indicated thermal efficiency (ITE) at the engine speed 1,800 rpm and part load net indicated mean effective pressure ($IMEP_{net}$) 2 to 5 bar. ITE of the engine increased with the $H_2$ concentration, compression ratio and engine load. With 45% of $H_2$ concentration, compression ratio 17.1 and $IMEP_{net}$ 5 bar, ITE of 41.5% was achieved, which is equivalent to that of only diesel fuel operation.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_1
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• pp.149-159
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• 2022

Biomass is material that is comprehensive of carbonaceous materials from plants, crops, animals, and algae. It has been used as one of heating fuel since the beginning the emergence of human beings. Since biomass is regarded as carbon-neutral energy source, it has recently been attracting attention as an energy source that can replace fossil fuels. The most widely applied field is distributed power generation, and a method of generating electric power by driving an internal combustion engine with syngas produced by gasifier is chosen. While the composition of the syngas produced in gasifiers changes depending on the air flowing into the reactor, commercialized gasifiers so far do not control the air flowing into the reactor. When the inner pressure in reactor increases, the air sucked into the reactor is reduced. That change of amount of air makes the composition of syngas varied. Those variations of composition of syngas cause the incomplete combustion hence the power output of engine drops, which is a critical weakness of the gasification technology. In this paper, to produce the uniformly composed syngas, PID control is applied. The result was shown when the amount of air into the reactor is supplied with the constant amount using PID control, the standard deviation of caloric values of syngas is around 2[%] of its average value. Meanwhile the gasifier without PID control has the standard deviation of caloric values is around 7[%]. Therefore, Adopting PID control to supply constant air to the gasifier is highly desirable.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.6
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• pp.159-164
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• 2007

The purpose of this study is to reduce harmful emission gases in the range of stable combustion without loss of a thermal efficiency. Therefore, effects of both exhaust gas recirculation(EGR) and synthetic gas addition on engine performance and emission were investigated in a gasoline engine. Synthetic gas(syngas), which is in general prepared from reforming gasoline, was utilized in order to promote stable combustion. The major components of syngas are H2, CO and $N_2$ gases. The percentage of syngas addition was changed from 0 to 30% in energy fraction and EGR rate was varied up to 30%. As a result, $COV_{IMEP}$ as a parameter of combustion stability was decreased and THC/$NO_X$ emissions were reduced with the increase of syngas addition. And $COV_{IMEP}$ was increased with the increase of EGR but $NO_X$ emission was greatly reduced. In addition, under the region where the EGR rate is around 20%, thermal efficiency was improved.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.349-352
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• 2008

This study has numerically modeled the combustion processes of the turbulent swirling premixed lifted syngas flames in the low-swirl burner (LSB). In these turbulent swirling premixed flames, the four tangentially-injected air jets induce the turbulent swirling flow which plays the crucial role of stabilizing the turbulent lifted flames. In the present approach, the turbulence-chemistry interaction is represented by the level-set based flamelet model. Numerical results indicate clearly that the present level-set based flamelet approach has realistically simulated the structure and stabilization mechanism of the turbulent swirling premixed lifted flames in the low-swirl burner. Computations are made for the wide range of the syngas chemical composition and the dilution level at two pressure conditions (1.0, 5.0 bar). Numerical results indicate that the lifted height in the LSB is increased by decreasing the H2 percentage and increasing the dilution level at the given equivalence ratio. It is also found that the flashback is occurred for the hydrogen composition higher than 80% at the equivalence ratio, 0.8. However, at the syngas composition range in the IGCC system, the stable lean-premixed lifted flames are formed at the low-swirl burner.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.463-469
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• 2012

Solar thermochemical syngas and hydrogen production process bv redox system of metal oxide was performed under direct irradiation of the metal oxide on the SiC ceramic foam device using solar simulator. $CeO_2/ZrO_2$ nanotube has been synthesized by anodic oxidation method. Syngas and hydrogen production process is one of the promising chemical pathway for storage and transportation of solar heat by converting solar energy to chemical energy. The produced syngas had the $H_2/CO$ ratio of 2, which was suitable for methanol synthesis or Fischer-Tropsch synthesis process. After ten cycles of redox reaction, $CeO_2$ was analyzed using XRD pattern and SEM image in order to characterize the physical and chemical change of metal oxide at the high temperature.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.493-502
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• 2012

Syngas laminar burning velocity measurements were carried out at atmospheric pressure and ambient temperature using the Bunsen flame configuration with nozzle burner as a fundamental study on flame stability of syngas fuel. Representative syngas mixture compositions ($H_2$:CO) such as 25:75%, 50:50% and 75:25% and equivalence ratios from 0.5 to 1.4 have been conducted. Average laminar burning velocities have been determined by the stabilized nozzle burner flames using the angle method, radical surface area method and compared with the data obtained from the other literatures. And the results of each experimental methodologies in the various composition ratios and equivalence ratios were coincided with the result of numerical simulation. Especially, it was confirmed that there was necessary to choice a more accurate measurement methodology even the same static flame method for the various composition ratios of syngas fuel including hydrogen. Also, it was reconfirmed that the laminar burning velocities gradually increased with the increasing of hydrogen content in a fuel mixture.

• Environmental Engineering Research
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• v.10 no.3
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• pp.131-137
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• 2005

The catalytic activity of precious metals(Rh, Pd, Pt) and nickel catalysts supported on ${\gamma}-Al_2O_3\;and\;CeO_2$ in the partial combustion of methane(PCM) to syngas was investigated based on the product distribution in a fixed bed now reactor under atmospheric condition and also on analysis results by SEM, XPS, TPD, BET, and XRD. The activity of the catalysts based on the syngas yield increased in the sequence $Rh(5)/CeO_2{\geq}Ni(5)/CeO_2>>Rh(5)/Al_2O_3>Pd(5)/Al_2O_3>Ni(5)/Al_2O_3$. Compared to the precious catalysts, the syngas yield and stability of the $Ni(5)/CeO_2$ catalyst were almost similar to $(5)/CeO_2$ catalyst, and superior to these of any other catalysts. The syngas yield of $Ni(5)/CeO_2$ catalyst was 90.66% at 1023 K. It could be suggested to be the redox cycle of the successive reaction and formation of active site, $Ni^{2-}$ and the lattice oxygen, $O^{2-}$ produced due to reduction of $Ce^{4-}$ to $Ce^{3-}$.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.23-29
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• 1999

Experimental studies are conducted to investigate the flame stability and the thermal/fuel NOx formation characteristics of the low calorific value (LCV) coal derived gas fuel. Synthetic LCV fuel gas is produced by mixing carbon monoxide, hydrogen, nitrogen and ammonia on the basis that the thermal input of the syngas fuel into a burner is identical to that of natural gas. The syngas mixture is fed to and burnt with air on flat flame burner. With the variation of the equivalence ratio for specific syngas fuel, flame behaviors are observed to identify the flame instability due to blow-off or flashback and to define stable combustion range. Measurements of NOx content in combustion gas are made for comparing thermal and fuel NOx from the LCV syngas combustion with those of the natural gas one. In addition, the nitrogen dilution of the LCV syngas is preliminarily attempted as a NOx reduction technique, and its effects on thermal and fuel NOx production are discussed.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.267-270
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• 2014

Since contaminants of syngas obtained from the biomass gasification are removed, the syngas is clean fuel. In this study a high-efficiency energy production system is developed. The system produces electricity using a waste pressure and feeds a low-pressure steam to Dyeing industrial complex. Also, iron oxide derived from dyeing sludge is utilized as a self-catalyst to reform a tar and reduce a tar emission from gasifier. This system increases the amount of syngas and finally achieves a highly efficient gasification.