• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.497-503
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• 2016

Flue gas desulfurization gypsum is produced from emission process of fossil fuel power plant to remove sulfur dioxide ($SO_2$) from exhaust gas. Production of flue gas desulfurization gypsum in Republic of Korea has been increasing due to the enforced regulations by government agency. Since flue gas desulfurization gypsum has characteristic that is similar to that of natural gypsum, there is a strong possibility for flue gas desulfurization gypsum to replace the role of natural gypsum. However, consumption of such material is still limited, only used for agricultural purposes or to make gypsum boards, it is necessary to expand the use of this material more aggressively. In this research, the chemical and mineralogical properties of flue gas desulfurization gypsum were investigated, and flue gas desulfurization gypsum with heat treatment was used to make cement paste. According to the results, it was found that flue gas desulfurization gypsum used in this experiment was a very high purity gypsum, and shown to have similar property to that of natural gypsum. Heat treating flue gas desulfurization gypsum above $100^{\circ}C$ was shown to bring beneficial effect on both compressive strength and drying shrinkage

• Clean Technology
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• v.20 no.1
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• pp.88-94
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• 2014

During the past decades much attention has been paid to the desulfurization of diesel oil which is important as a source for the fuel cells to prevent the sulfur poisoning of both diesel steam reforming catalyst and electrode of fuel cell. Although alternative desulfurization techniques have been investigated, desulfurization for ultra-low sulfur diesel (ULSD) is still challenged. Therefore, this research focuses on the desulfurization of commercial ULSD for the application to molten carbonate fuel cell (MCFC). Herein, the performances of several kinds of commercial adsorbents based on activated carbons, zeolites, and metal oxides for desulfurization of ULSD were screened. The results showed that metal oxides based materials can feasibly reduce sulfur concentration in ULSD to a level of 0.1 ppmw while activated carbons and zeolites did not reach this level at current conditions.

• Resources Recycling
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• v.25 no.5
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• pp.14-27
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• 2016

Theoretical reviews of integrated gasification combined cycle one of the clean coal technologies and trends in the study and technology development for high temperature desulfurization sorbents were investigated. Reactivity, durability and abrasion resistance is an important key for development of high temperature desulfurization sorbents, the kind of things include calcium, zinc, manganese, iron and copper-based sorbents. Current status of high temperature desulfurization sorbents, manufacturing techniques of zinc-based sorbent in advanced countries has commercialized. In case of Korea, various research studies are underway to commercialize the Zn and non Zn-based high temperature desulfurization sorbents to cheaper and superior capability using various supports.

• Clean Technology
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• v.5 no.2
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• pp.79-86
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• 1999

Mutant strain EID was developed by treating Gordona sp. CYKS1 with ethylmethanesulfone, and the desulfurization characteristics of dibenzothiophene(DBT) by mutant EID was investigated. Strain EID desulfurized DBT to 2-hydroxybiphenyl (2-HBP) by 4S pathway. Desulfurization rate of the strain EID was $4.0{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$, while that of the wild type CYKS1 was $2.6{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$. The effect of glucose concentration supplied as the carbon source on the DBT desulfurization showed that DBT desulfurization rate was enhanced as the glucose concentration increased. Maximum DBT desulfurization rate was $11.1{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$ at 2.0 mM DBT concentration. As end-products such as 2-HBP and sulfate concentrations increase, DBT desulfurization activity of the strain EID decreased. When 0.2 mM of 2-HBP was added in the medium, no growth and desulfurization activity was observed. When 0.5 g/L $Na_2SO_4$ was simultaneously supplied with DBT, DBT desulfurization rate was$1.4{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.9-14
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• 2001

This study was performed to develop the modified FGD(Flue Gas Desulfurization) process which can eliminate the possibility of generating secondary pollutants. Limestone was regenerated by adding ammonium hydroxide and carbon dioxide, and reusing it as a absorbent in FGD gypsum Process. A series of the new or modified FGD process which include desulfurization and regeneration limestone from CaSO$_3$. 1/2H20 and CaSO4 . 2H2O, were carried out under various experimental conditions. The results showed that the optimum injection ratio for regeneration of limestone was 0.3 ml/min of CO2 flow rate, 2 ml of NH4OH per 0.01 M of regent grade CaSO4 . 2H20O and the optimum regeneration temperature was 50. The increaser was the number of times of limestone regeneration, the faster was the breakthrough point of desulfurization at the desulfurination process which the regenerated limestone was used. Then the efficiency of desulrurization was decreased. This study can be confirmed the possibility for reuse of regenerated limestone due to the similarity of desulfurization characteries both reagent grade calcium carbonate and regenerated calcium carbonate. Finally, it appeared that the new technology using regenerated 1imestone can be applied to the FGD process.

• Particle and aerosol research
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• v.14 no.3
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• pp.73-80
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• 2018

Recently, there has been much research on the effect of ultrafine dust on human body with increasing interest in the ultrafine dust. In the Republic of Korea, there are many old thermal power plants, and the amount of ultrafine dust emitted from the thermal power plants is reported to be about 14% of the total amount of domestic fine dust. Therefore, the amount of fine dust from the flue gas desulfurization facility in the thermal power plant needs be reduced. In this study, we made an experimental setup to simulate a flue gas desulfurization facility and analyzed the physical characteristics of the particles passing through a mist eliminator. Experiments were carried out to investigate the collection efficiency of the mist eliminator by using the Arizona Test Dust in a dry environment, and then spraying limestone slurry into the flue gas desulfurization system equipped with the mist eliminator to examine the size and morphology of limestone particles upstream and downstream of the mist eliminator. Cut-off size of the mist eliminator was formed at about $6{\mu}m$. The result of this study is expected to be helpful for designing an electrostatic precipitator for removing particles passing through the mist eliminator.

• Journal of the Korean Ceramic Society
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• v.53 no.6
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• pp.676-681
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• 2016

For the purpose of reducing the amount of limestone, which is used as a desulfurization agent to absorbing $SO_X$ gas in thermal power plants, and to recycle limestone sludge generated from a steel mill, limestone sludge was utilized as a desulfurization agent. In this study, cement, made of flue gas desulfurization (FGD) gypsum obtained in a desulfurization process using limestone sludge, was manufactured then, experiments were conducted to identify the physical properties of the paste and mortar using the cement. The results of the crystal phase and microstructure analyses showed that the hydration product of the manufactured cement was similar to that of ordinary Portland cement. No significant decline of workability or compressive strength was observed for any of the specimens. From the results of the experiment, it was determined that FGD gypsum manufactured from limestone sludge did not influence the physical properties of the cement also, quality change did not occur with the use of limestone sludge in the flue gas desulfurization process.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.578-583
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• 2003

The desulfurization genes (dszABC) were cloned from Gordonia nitida. Nucleotide sequences similarity between the dszABC genes of G. nitida and those of Rhodococcus rhodochrous IGTS8 was 89%. The similarities of deduced amino acids between the two were 86% for DszA, 86% for DszB, and 90% for DszC. The G. nitida dszABC genes were expressed in several different Escherichia coli strains under an inducible trc promoter. Cultivation of these metabolically engineered E. coli strains in the presence of 0.2 mM dibenzothiophene (DBT) allowed the conversion of DBT to 2-hydroxybiphenyl (2-HBP), which is the final metabolite of the sulfur-specific desulfurization pathway. The maximum conversion of DBT to 2-HBP was 16% in 60 h. Recombinant E. coli was applied for the deep desulfurization of diesel oil supplemented into the medium at 5% (v/v). Sulfur content in diesel oil was decreased from 250 mg sulfur/1 to 212.5 mg sulfur/1, resulting in the removal of 15% of sulfur in diesel oil in 60 h.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.11a
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• pp.73-77
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• 2000

A great deal of research has been carried out in the last twenty some years to develop high temperature desulfurization. For example, the efficiency of advanced power generation processes based on the integrated gasification combined cycle (IGCC) can be increased significantly with high temperature desulfurization. Much of the recent high temperature desulfurization research has concentrated on zinc-based sorbents such as zinc ferrite(ZnFe$_2$O$_4$) and zinc titanate(ZnO.xTiO$_2$) due to its thermodynamic advantage in capturing H$_2$S molecules.(omitted)

• Journal of Environmental Science International
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• v.7 no.5
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• pp.693-696
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• 1998

We tried to develope a desulfurization sorbent using eggshell for recycling, practicability, and economic development. The calcination character of the eggshell was examined by thermal gravimetric analysis and qualitative-quantitative character by X-ray diffractometer(XRD) and scanning electron microscope(SEM). The calcination was occurred easily in the case of eggshell and its form was changed from calcite($CaCO_3$) to lime(CaO). The grain and pore sizes of the calcined sample after base-treatment were larger and more crystallic. The adsorption ability of the eggshell was two- to six-times in the calcination temperature more than in the grain size. Therefore, the eggshell was thought to be usable as the desulfurization sorbent.