• New & Renewable Energy
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• v.7 no.2
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• pp.10-17
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• 2011

Korea is the 11th largest energy consumption country and 96% of its total energy consumption depends on imports from overseas. Therefore it is a very important task to secure renewable energy sources which can reduce both the carbon-dioxide emission and dependency on overseas energy imports. Among the various renewable energy sources, organic wastes are important sources. In Korea, 113 million toe of methane is generated from organic wastes annually, but only 3.7% is effectively used for energy conversion. Thus, it is very important to make better use of organic wastes, especially for power generation. The goals of this project are to develope the fuel supplying system of Bio Gasturbine (GT) for 5MW-class co-generation system. The fuel supplying system mainly consists of $H_2S$ removal system, Bio Gas compression system, Siloxane removal system and moisture separating systems. The fuel requirement of 5MW-class GT is at around 60% of $CH_4$, $H_2S$ (<30 ppm), Siloxane(<10 mg/$nm^3$) and supply pressure (> 25 bar) from biogas compressor. Main mechnical charateristics of Bio Gasturbine system have the specific performance; 1) high speed turbine speed (12,840 rpm) 2) very clean emmission NOx (<50 ppm) 3) high efficiency of energy conversion rate. This paper focuses on the development of design technology for food waste biogas pretreatment system for 5MW-class biogas turbine. The study also has the plan to replace the fuel of gas turbine and other distributed power systems. As the increase of bioenergy, this system help to contribute to spread more New & Renewable Energy and the establishment of Renewable Portfolio Standards (RPS) for Korea.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.373-377
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• 2012

Among the fossil fuels, the brown coal is a great deal of resources. However, it is hardly used due to the high moisture content and low calorific value. It has both the week points such as spontaneous combustion and high volatile content and the strong points such as the low-sulfur and low ash content. If we overcome these week points, the using amount of brown coal would be increased. Also, it is well known that biomass is one of the important primary renewable energy sources because of carbon neutral energy. Furthermore, the utilization of biomass has been more and more concerned with the depletion of fossil fuel sources as well as the global warming issues. Combustion and thermal decomposition of biomass is one of the more promising techniques among all alternatives proposed for the production of energy from biomass. In this study, combustion of brown coals and mushroom waste was done. Mass change of samples and emission of hydrocarbon components were measured. As the results, we obtained combustion rate constant. Also activation energy was calculated in char combustion step. Hydrocarbon components were more generated in low oxygen concentration than high. Emission amount of hydrocarbon components in mushroom waste was significantly increased comparing to brown coal.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.49-57
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• 2016

In this study, a thermal hydrolysis technology was used to treat the poultry carcasses that were killed due to Avian Influenza (AI) occurrence, as well as to determine the possibility of fueling for the resultant products. Experimental results showed that the poultry carcasses were liquefied except for sand, and showed the optimum efficiency at $190^{\circ}C$ and operating time of 60 minutes. It has been shown that liquid products obtained after thermal hydrolysis has good conditions for fuel conversion since it had high carbon contents and calorific value, as well as low ash content. In addition, it was possible to operate the thermal hydrolysis facility by using only the waste heat generated in the combustion without injecting the auxiliary fuel, and the exhaust gas generated in the combustion has a small influence on the atmosphere.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.153-159
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• 2000

Large-scale simulated lysimeter experiments were conducted for 4 years as a fundamental study to develop enhanced landfill stabilization method, which accelerate stabilization time and make efficient practical use of self-purification capacity of pollutants in semi-aerobic solid waste landfill. The amount of TOC(total organic carbon) decomposition increased as the landfill depth increased. In case of T-N(total nitrogen), the self-purification capacity increased linearly with the landfill thickness until it reached a maximum level of 6 m. Beyond this level, the self-purification capacity was not increased. The results from lysimeter experiments indicate that 6m of landfill thickness is optimum for self-purification capacity of pollutants considering the mass balance of TOC and T-N.

• Journal of Biosystems Engineering
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• v.25 no.6
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• pp.481-488
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• 2000

This study was initiated in order to find alternative fuel substituting for light oil the most common fuel for heating greenhouse. The tire oil used in this research was produced by pyrolysis process, one of the final products besides steel string and carbon black in which waste tires as a form of chopped pieces broken by shredding machine are heated up to 200~30$0^{\circ}C$ with maximum restraining of oxygen supply. In order to justify light oil equivalent qualities in tire oil combustion characteristics were defined in the way of comparing kinetic viscosities in the wide range of temperature flame sizes and exhaust gas components in the various combustion conditions. We found that kinetic viscosity of tire oil was lower than light oil by 1 to 2 cSt in the temperature range showing better flowing mobility in the fuel line of the burner and no significant difference in flame size between the two oils in the all combustion treatments. However much more NO and SO$_2$ were detected from the exhaust gases of tire oil than light oil combustions. In fact tire oil contains more nitrogen and total sulfur, by 25 times and 40 times respectively than light oil according to the composition analysis. Tolerable limit for SO$_2$discharge amount defined by the national air pollution standards is under 540ppm so tire oil combustion satisfies the requirement though. It is desirable if sulfur and nitrogen filtering process shall be added in the tire oil production line. Except the exhaust gas components all greenhouse heating qualities of tire oil including hot air temperature are very identical to those of light oil.

• Environmental Analysis Health and Toxicology
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• v.11 no.1_2
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• pp.31-39
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• 1996

Leachate from municipal solid waste (MSW) landfill, effluent from leachate treatment plant, and ground water sample from a monitoring well near landfill site were tested for an acute toxicity. Microtox toxicity test was used for testing the acute toxicity of leachate and other samples. EC$_{50}$ values which a concentration of pollutant for reducing 50% light output from luminescent bacteria, Photobacterium phosphoreum were determined to assess the toxicity of pollutants as well as the relative toxicity. In addition, characteristics of leachate were studied and compared to those of phenol and pentachlorophenol (PCP) which are typical aquatic toxic pollutants. For leachate, EC$_{50}$ for 30 min incubation was 10.8%, while for phenol and PCP, 46 ppm and 1.2 ppm, respectively. the relative toxicity of treated leachate by in situ aeration with activated sludge was reduced to more than 75% of toxicity of the untreated leachate. Microtox toxicity test was failed to figure out EC$_{50}$ values for groundwater from a monitoring well since the relative toxicity of the unconcentrated sample was too low to estimate EC$_{50}$. Addition of activated carbon to leachate was reduced the relative toxicity. The reduction Pattern of the relative toxicity of leachate by mechanical aeration was similar to that of PCP, but different from that of phenol. These findings suggest that the toxicity of leachate may come from PCP-like toxic compounds rather than phenol-like one. In conclusion, the process of aeration with activated sludge might be very important to reduce the environmental toxicity of leachate. And Microtox test could be a reasonable bioassay for screening and monitoring the environmental toxicity of leachate from municipal solid waste landfill as well as for determining the reduction efficiency of the leachate toxicity by various treatment processes in leachate treatment plant.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.381-386
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• 2015

Environmental pollution and alternative energy has attracted increasing interest. The use of diesel engines is expected to increase in the world owing to their fuel economy. The problem of air pollution emissions from marine engines is causing a major concern in many areas. An alternative fuel was introduced as an environmentally friendly fuel to reduce the toxic emissions from conventional fossil fuels. Biodiesel fuel, which is a renewable energy is highlighted as environmentally friendly energy. This energy can be operated in regular diesel engines when it is blended with invariable ratios without making changes. In this study, a bio-diesel fuel was produced from waste cooking oil and applied to a marine diesel engine to examine the effects on the characteristics of combustion. Waste cooking oil contains a high cetane number and viscosity component, a low carbon and oxygen content. As a result, the brake specific fuel consumption was increased, and the cylinder pressure, rate pressure rise and rate of heat release were decreased.

• Clean Technology
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• v.18 no.4
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• pp.360-365
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• 2012

With rapid increase in municipal solid waste (MSW) due to the rising economy, solid waste gasification emerges as one of the promising technologies. Separation of the carbon monoxide (CO) and hydrogen ($H_2$) from syngas obtained by gasification of MSW was studied using the polyamide composite membrane. The separation characteristics of the CO and $H_2$ were studied at different gas flow rates and stage cuts. The permeability of CO and $H_2$ along with the selectivity of $H_2$ with respect to CO was obtained. Furthermore, the Arrhenius plots were obtained to estimate the activation energies of CO and $H_2$ permeabilites.

• Journal of the Korea Institute of Building Construction
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• v.13 no.4
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• pp.351-359
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• 2013

Blast furnace slag (BFS) have many advantages that are related to effective value improvement on applying to concrete while side effects of blast furnace slag also appear. Thus, research team conducted an experiment with high volume slag to see if the attribute of waste alkali accelerator for mixing rate, mixed use of NaOH and $Na_2SiO_3$, and early strength agent for mixing rate for replacement ratio and for the types of the stimulants in order to increase the use of blast furnace slag1s powder. As the result of the experiment, when it comes to compression strength, all of the alkali stimulants have been improved as the replacement rate increases except for sodium hydroxide. Among the alkali stimulants, sodium silicate was high on dynamic elastic modulus and absorption factor. In case of early strength agent, the mix of mixing 1.5% and blast furnace slag 75% have showed high strength enhancement. In event of Waste Alkali accelerator, it has showed different consequences for each experiment.

• Asian Journal of Atmospheric Environment
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• v.2 no.2
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• pp.102-108
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• 2008

In China, energy and environmental problems are becoming serious owing to rapid economic development. Coal is the most problematic energy source because it causes indoor and outdoor air pollution, acid rain, and global warming. One type of clean coal technology that has been developed is the coal-biomass briquette (or bio-briquette, BB) technique. BBs, which are produced from pulverized coal, biomass (typically, agricultural waste), and a sulfur fixation agent (slaked lime, $Ca(OH)_2$) under high pressure without any binder, have a high sulfur-fixation effect. In addition, BB combustion ash, that is, the waste material, can be used as a neutralization agent for acidic soil because of its high alkalinity, which originates from the added slaked lime. In this study, we evaluated the suitability of alternative biomass sources, namely, aquatic plants, as a BB constituent from the perspective of their use as a source of energy. We selected three types of aquatic plants for use in BB preparation and compared the fuel, handling, and environmental characteristics of the new BBs with those of conventional BBs. Our results showed that air-dried aquatic plants had a higher calorific value, which was in proportion to their carbon content, than agricultural waste biomass; the compressive strength of the new BBs, which depends on the lignin content of the biomass, was high enough to bear long-range intracontinental transport in China; and the new BBs had the same emission control capacity as the conventional BBs.