• Resources Recycling
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• v.28 no.4
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• pp.15-22
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• 2019

Coal combustion products are generated during coal combustion and can be grouped into fly ash and bottom ash depending on collection methods. Fly ash and bottom ash can be recycled for various purposes based on their characteristics. Australia is the fourth largest coal production country in the world and reuses coal ash as cement, concrete, mine filler, and agricultural soil amendment. When fly ash is used as a supplement for cement and concrete, strength of the cement and the durability of the concrete can be improved. Use of coal combustion product for mine backfill stabilizes underground mine voids and stores a large amount of coal ash in the voids. Because of alkalinity of coal combustion products, it can neutralize acid mine drainage when used for mine backfill. In addition, it can be used as an agricultural soil amendment to improve acidity and physical properties of the soil and to supply plant nutrients. Recycling of fly ash in Australia will be further expanded because of its low trace element contents that can be toxic to plants and low radioactive element contents existing within soil background concentrations. The characteristics of coal combustion products are related to the characteristics of the coal used for combustion, and since Korea imports coal from Australia, Korean coal combustion products also can be recycled for various purposes.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.425-432
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• 2023

In this study, we aim to develop a carbon-reducing concrete technology by incorporating biochar. Performance evaluation experiments were conducted on concrete mixtures containing biochar with insulating and carbon-capturing properties, which are essential for key infrastructure sectors such as construction and tunnels. Concrete mixtures were designed with different biochar incorporation rates of 0 %, 5 %, 10 %, 15 %, and 20 %, as w ell as w ater-to-binder ratios of 0.25, 0.30, 0.35, and 0.40. To assess the physical properties of each mixture, unit weight, total porosity, and permeability were measured, while mechanical properties were determined through the measurement of concrete compressive and flexural strengths. Key factors for enhancing the insulating effect of carbon-reducing concrete containing biochar were identified through regression analysis, indicating a close correlation among biochar incorporation rate, unit weight, concrete strength, and thermal conductivity. It is anticipated that it can be utilized as an insulating material to enhance thermal performance in northern regions with severe winter climates.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.531-537
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• 2009

Climate changes including environmental disasters after reckless industrialization have been globally witnessed. Considerable attention on the imminent need for developing CCS(Carbon dioxide Capture and Storage) methodologies to minimize the emission thus has been given. Chemical absorption is particularly regarded important because of its commercial availability and applicability to large scale plants. This paper addresses recent trends of chemical absorption technologies and the need for the further research on the topic from the perspective of process systems engineering(PSE).

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.2
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• pp.32-37
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• 2001

This article is to provide reasonably accurate vehicle emission estimates for the four sampled fuels which are commercially available across the nation. Emission quantities are obtained by testing a vehicle on a chassis dynamometer and capturing a sample of the emissions from the tailpipe in vehicle. The vehicle is driven following a particular pattern of idle, acceleration, cruise, and deceleration. Shown here is the trace of the test cycle known as the CVS-75 Mode which is used to certify the emission performance standards. The mode of CVS-75 consists of a cold start cycle, a hot stabilized cycle, and a hot start cycle. Emissions for the pollutants are measured in vehicle testing. These are carbon monoxide (CO), oxides of nitrogen (NOx), and total hydrocarbon (THC). The test results summarized in this report indicate that the differences for the amount of emission are quantitatively minimal.

• Resources Recycling
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• v.9 no.1
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• pp.21-26
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• 2000

Extraction of manganese was investigated with nitric acid from the dust which was generated in the AOD process producing a medium-low carbon ferromanganese from a high carbon ferromanganese. Content of manganese oxide in the dust was about 90%, and phase of it was confirmed as $Mn_3O_4$, The $Mn_3O_4$ particles was agglomerated as spherical shape, and had a lot of pore and crack inside. Maximum recovery of Mn from the sample in the leaching step was about 67% and residue was the amorphous $MnO_2$. The extraction of Mn increased with increasing temperature, but decreased in proportion to concentration of nitric acid. The extraction rate was in good agreement with the pore diffusion model.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.538-547
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• 2015

Test activated carbon fiber (ACF) was prepared from Polyacrylonirile (PAN) through oxidation and chemical activation. Immersion of ACF precursors in the aqueous KOH solution enhanced the surface structure, as examined by BET pore analysis. Specific surface area increased greatly from less than $70m^2/g$ to $1226m^2/g$ with 4 M KOH, and total pore volume also rose up to $0.483cm^3/g$. In particular, it was found that micropores favorable for $CO_2$ molecule capture occupied more than 95%. Maximum $CO_2$ adsorption capacity was 3.59 mmol/g at 298 K. Low depth of pores in the present ACF may facilitate the molecules' desorption for its regeneration.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.243-251
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• 2010

Nitrogen oxides (NOx) in combustion flue gas are currently mitigated by chemical processes such as catalytic reduction, absorption and adsorption. However, development of environmentally sustainable biological processes is necessary in the near future. In this paper, the up-to-dated R&D trend of biological methodologies regarding NOx removal was reviewed, and their advantages and disadvantages were discussed. The principles and applications of bacterial system including nitrification and denitrification and photosynthetic microalgae system were compared. In order to enhance biological treatment rate and performance, the insoluble nitric oxide (NO) should be first absorbed using a proper solubilization agent, and then microbial degradation or fixation is to be followed. The use of microalgal system has a good prospect because it can fix $CO_2$ and NOx simultaneously and requires no additional carbon for energy source.

• International Journal of Highway Engineering
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• v.15 no.6
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• pp.69-78
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• 2013

PURPOSES : In this study blast furnace slag, an industrial byproduct, was used with an activating chemicals, $Ca(OH)_2$ and $Na_2SiO_3$ for carbon capture and sequestration as well as strength development. METHODS : This paper presents the optimized mixing design of Carbon-Capturing and Sequestering Activated Blast-Furnace Slag Mortar. Design of experiments in order to the optimized mixing design was applied and commercial program (MINITAB) was used. Statistical analysis was used to Box-Behnken (B-B) method in response surface analysis. RESULTS : The influencing factors of experimental are water ratio, Chemical admixture ratio and Curing temperature. In the results of response surface analysis, to obtain goal performance, the optimized mixing design for Carbon-Capturing and Sequestering Activated Blast-Furnace Slag Mortar were water ratio 40%, Chemical admixture ratio 58.78% and Curing temperature of $60^{\circ}C$. CONCLUSIONS : Compared with previous studies of this experiment is to some extent the optimal combination is expected to be reliable.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.16-23
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• 2019

Cooking oil in kitchen-fog is the most harmful factor to the health of a cook. The proposed filter is a tool that protects the cooked state, to prevent users from inhaling oil mist in the kitchen. Due to efficiency issues, existing filters are of the mesh type or baffle type. In this paper, CFD analysis is carried out to select a filter with low pressure loss and low efficiency, and to attach the sub-filter to improve efficiency. The results of the analysis on the collection efficiency and pressure loss of three sub-filters, i.e., circle type, droplet type, and cone type, showed that the collection efficiency was 64.09% and the pressure loss was 1.26 mmAq when the circle type sub-filter was applied. The position of the sub-filter showed the best efficiency and pressure loss when it was located at the bottom of the center of the gap of the main filter.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.3
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• pp.179-188
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• 2007

In this work $^{14}C\;and\;^3H$ distribution characteristics of spent resins from nuclear power plants(NPPs), pressurized water reactors(PWRs), was investigated. It was found that the recovery percent of $^{14}C$ by the wet oxidation-acid stripping was $81%{\sim}100%$ for the added activity range of $^{14}C,\;0.72\;Bq{\sim}460\;Bq$, and it was not affected by the kinds of stripping acids, 3N-HCl, $3\;N-HNO_3\;and\;3\;N-H_2SO_4$. And the recovery percent of $^3H$ by distillation using the same apparatus was $81%{\sim}101%$ for the added activity range of $^3H,\;0.60\;Bq{\sim}435\;Bq$. Among the tested stripping acids, 3\;N-HCl, $3\;N-HNO_3\;and\;3\;N-H_2SO_4$, only the trapped $^3H$ solution by distillation in $3\;N-H_2SO_4$ was compatible with the 3H scintillator, Ultimagold XR. Neither of the $^{14}C\;and\;^3H$ trapping solutions from the spent ion exchange resin samples by the wet oxidation-3 $N-H_2SO_4$ stripping contained gamma nuclides. However, some gamma nuclides, $^{60}Co,\;^{134}Cs,\;^{137}Cs\;and\;^{54}Mn$, were found in the trapped $^3H$ solutions of the spent resins by the wet oxidation-3 N-HCl stripping. It was the same for the $^3H$ trapping solutions of the spent resins by Sample Oxidizer(PACKARD MODEL 307). Meanwhile only two nuclides, $^{134}Cs,\;and\;^{134}Cs$, were found in the $^{14}C$ trapping solutions of the spent resins by Sample Oxidizer(PACKARD MODEL 307). It was found that most of the $^{14}C$ in the spent resins existed as inorganic carbon form, more than about 70% of the total $^{14}C$ content. Among the analyzed 30 spent ion exchange resin samples, the average concentration of $^{14}C$ and $^3C$ for the high radioactive samples, 8 samples, was $19000\;Bq/g{\pm}41000\;Bq/g,\;670\;Bq/g{\pm}460\;Bq/g$ and that for the low radioactive samples, 22 samples, was $4.2\;Bq/g{\pm}4.3\;Bq/g,\;6.0\;Bq/g{\pm}5.3\;Bq/g$, respectively. And the average $^{14}C/^3H$ ratio for the high radioactive samples, was higher, 28, than that of low radioactive samples, 0.70. Some linear relationship trend was found between the activity concentrations of $^{14}C\;and\;^3H$.