• Transactions of the Korean Society of Automotive Engineers
• /
• v.8 no.4
• /
• pp.59-67
• /
• 2000

Recently the world is faced with the very serious problems related to the increasing use of the conventional petroleum fuels. THe air pollutions in big cities were also occurred by the exhaust emissions from automobiles. many researchers have been attracted various oxygenated fuels as an alternative fuel and a renewable fuel for the measure of these problems. In this study the effect of oxygen in fuel on the exhaust gas emissions has been investigated with oxygenated fuels as an alternative fuel for diesel engine. The exhaust gas emission were investigated by comparing with that of the diesel fuel. The vegetable fuel oil such as soybean oil gives lower smoke level than that with diesel fuel. Furthermore the smoke emission is more affected by the oxygen content in fuel than by the fuel viscosity. This study concluded that the fuels including oxygen might be a good measure to reduce smoke in diesel engine because the oxygen strongly influenced the combustion process.

• 한국연소학회:학술대회논문집
• /
• 2013.06a
• /
• pp.9-10
• /
• 2013

This study reports the results of an experimental investigation of emission and temperatures from the syngas-air premixed flame with a various mixture composition in the region of large equivalence ratios. The effects of hydrogen contents and equivalence ratios on the flame velocity, which reported before, and emission of syngas fuel are examined. In this study, representative syngas mixture compositions ($H_2:CO$) such as $H_2:CO=10:90$, 25:75, 50:50 and 75:25 and equivalence ratios from 0.5 to 5.0 have been conducted. The emissions of syngas fuel were measured by the high precision analyzer with enclosure configuration and the adiabatic temperatures are calculated by used Chemkin basis. The NOx emission level is coincided relatively well with the adiabatic temperature distributions in lean mixture conditions, but for rich mixture conditions NOx level was also increased again even though the adiabatic temperature decreases. Such an increasing characteristics in rich mixture conditions is coincided well with the tendency that rather the flue gas temperature increases.

• International Journal of Automotive Technology
• /
• v.2 no.4
• /
• pp.123-133
• /
• 2001

An important goal in diesel engine research is the development of a means to reduce the emission of oxides of nitrogen ($NO_x$) and soot particulate. A phenomenological model based on the multizone concept is used in the current paper to analyze and compare the effects of exhaust gas recirculation (EGR) and split fuel injection on emission from a compression-ignited, direct-injection engine. The present results show that $NO_x$ can be reduced with a minimum penalty of soot particle emission with cooled EGR. Compared with EGR, split fuel injection has a higher soot penalty at a given level of $NO_x$ reduction.

• Advances in environmental research
• /
• v.9 no.2
• /
• pp.123-133
• /
• 2020

A time series dataset was conducted to ascertain the effect of water table on the variability in and emission of CH₄ and CO₂ concentrations at a closed landfill site. An in-situ data of methane/carbon dioxide concentrations and environmental parameters were collected by means of an in-borehole gas monitor, the Gasclam (Ion Science, UK). Linear regression analysis was used to determine the strength of the correlation between ground-gas concentration and water table. The result shows CH₄ and CO₂ concentrations to be variable with strong negative correlations of approximately 0.5 each with water table over the entire monitoring period. The R² was slightly improved by considering their concentration over single periods of increasing and decreasing water table, single periods of increasing water table, and single periods of decreasing water table; their correlations increased significantly at 95% confidence level. The result revealed that fluctuations in groundwater level is the key driving force on the emission of and variability in groundgas concentration and neither barometric pressure nor temperature. This finding further validates the earlier finding that atmospheric pressure - the acclaimed major control on the variability/migration of CH₄ and CO₂ concentrations on contaminated sites, is not always so.

• Korean Journal of Agricultural Science
• /
• v.47 no.3
• /
• pp.437-443
• /
• 2020

The aim of this study was to evaluate the effect of Lactobacillus acidophilus probiotic (LAP) product supplementation on the blood profile, fecal noxious gas emission, and fecal shedding of lactic acid bacteria and coliform bacteria in healthy adult Beagle dogs. In total, 14 Beagle dogs with an average initial body weight of 10.19 ± 0.61 kg were randomly assigned into two dietary treatments,with and without LAP supplementation, for a 28-day feeding trial. At the end of the experiment, there was no significant (p > 0.05) difference in the concentration of serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), white blood cell (WBC), red blood cell (RBC), blood lymphocyte percentage, fecal hydrogen sulfide (H₂S) and total mercaptans (R.SH) emission, and fecal coliforms counts. However, the serum concentrations of the triglyceride and fecal ammonia (NH₃) emission of the LAP treatment were significantly (p < 0.05) decreased in the group compared with the CON dogs. Fecal total lactic acid bacteria counts were significantly (p < 0.05) increased in the LAP treatment. In conclusion, the supplementation of LAP in Beagle dog diets could decrease the blood triglyceride level and enhance the gut Lactobacillus count which may have positive effects on dogs.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.1
• /
• pp.73-78
• /
• 2004

A highly sensitive detecting method has been developed for determining part per billion of sulfur in $H_2S$/Ar plasma. The method is based on the excitation of Ar/$H_2S\;or\;Ar/H_2S/O_2$ mixture in hollow cathode glow discharge sustained by radiofrequency (RF) or 60 Hz AC power and the spectroscopic measurement of the intensity of emission lines from electronically excited $S_2^*\;or\;SO_2^*$ species, respectively. The RF or AC power needed for the excitation did not exceed 30 W at a gas pressure maintained at several mbar. The emission intensity from the $SO_2^*$ species showed excellent linear response to the sulfur concentration ranging from 5 ppbv, which correspond to S/N = 5, to 500 ppbv. But the intensity from the $S_2^*$ species showed a linear response to the $H_2S$ only at low flow rate under 20 sccm (mL/min) of the sample gas. Separate experiments using $SO_2$ gas as the source of sulfur demonstrated that the presence of $O_2$ in the argon plasma is essential for obtaining prominent $SO_2^*$ emission lines.

• Journal of Climate Change Research
• /
• v.4 no.3
• /
• pp.291-303
• /
• 2013

After establishing national greenhouse gas emission reduction goals, the South Korean government has been pursuing sector- and industry-specific greenhouse gas emission reduction measures; in support of which, metropolitan city / state governing entities, such as Gyeonggi Province, etc., have been in lock steps by establishing and executing climate change measures that are appropriate for the regional characteristics. However, in the case of local governments, difficulties abound due to the fact that the per-unit greenhouse gas emission amounts and the future emission estimates for establishing reduction targets are not clear. In order to establish correct climate change measure policies, the policy directions and the assessment of verified greenhouse gas emission amounts would need to serve as the basis, and along with the national level climate change effect and vulnerability assessment, there's a need to develop methodologies that take into consideration the local characteristics and conditions. To this end, this study calculated the greenhouse gas emission amounts of the City of Siheung, a basic local government in Gyeonggi Province, by using the GEBT (Greenhouse gas Emission Business-as-usual Tool) developed by the National Institute of Environmental Research to facilitate easy calculations of BAU (business-as-usual) emission quantities by local governing entities.

• New & Renewable Energy
• /
• v.7 no.3
• /
• pp.67-73
• /
• 2011

MGT fuelled by landfill gas was tested to asses feasibility of its exhaust gas application for $CO_2$ enrichment. The exhaust gas was analyzed during start-up and normal operation with different MGT load conditions. Due to the changes of air/fuel ratio and combustion mode, $O_2$, $CO_2$, CO and NOx concentration were varied within wide ranges during the MGT start-up. Especially, NOx emissioin level was increased up to 20.01 ppmv. Different tendencies of $O_2$, $CO_2$, CO and NOx concentrations were observed with MGT output changes. $O_2$ and CO concentrations were shown to be decreased and NOx and $CO_2$ concentrations were shown to have opposite trends. NOx emission level (0.8~1.88 ppmv) was very low compared to other types of combustion based power generation equipment. Unburned hydrocarbon emission level was substantially decreased with MGT load increase. Especially, $C_2H_4$ concentration was below the detection limit(0.2 ppmv) around the nominal load condition. The exhaust gas from landfill gas fuelled MGT system was shown to be feasible for $CO_2$ fertilization. Concentrations of major components were within or below the maximum allowable ranges.

• International Journal of Advanced Culture Technology
• /
• v.4 no.1
• /
• pp.10-18
• /
• 2016

In the present study, a single cylinder four stroke dual fuel diesel engine was tested to investigate the performance and emission characteristics of various test fuels. The engine was tested in dual fuel mode using diesel and Karanja biodiesel blends as pilot fuel along with Natural gas as primary fuel with a constant gas flow rate under different loading conditions. From the experimentation it was found that smoke opacity and oxides of nitrogen (NOx) are at low level for all the prepared test fuels in dual fuel mode but the emissions of carbon monoxide (CO), carbon dioxide ($CO_2$) and hydrocarbon (HC) were found higher. In comparison to diesel fuel, by increasing the blend percentage different emission parameters are found to be reduced. At different loading conditions all the test fuels show poor performance in dual fuel mode of operation when compared with single mode of operation with diesel and biodiesel. With increase in gas flow rates, except (NOx) and smoke emissions, the other emission parameters like CO, HC and $CO_2$ values increased for all test fuels. Again, all blended fuels showed lower performance compared to diesel. The maximum pilot fuel savings for diesel was found decreasing with the increase in karanja biodiesel. From the present work it may be concluded that Karanja biodiesel with Natural gas in dual mode can be can used as promising alternative for diesel with some required engine modifications and further research must be carried out to minimize the emissions of CO, HC and $CO_2$.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.928-933
• /
• 2009

The purpose of this study is to examine the energy consumption, carbon dioxide emission & energy cost of district heating using sewage source. The annual TOE of heat pump using sewage source save 37.1 percent than city gas boiler. And annual carbon dioxide emission of heat pump cut down 41.3 percent than city gas boiler. If it charges the rate schedule for district heating to apartment resident, collected amount are 3,127,170 thousand won. As energy cost of heat pump & circulation pump are 1,378,072 thousand won. the profits are 1,749,098 thousand won. As payback period is 8.97years, applicability is low level. However, it has advantages in energy consumption, carbon dioxide emission & energy cost. Therefore, it needs to proceed through government assistance.