• Journal of Energy Engineering
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• v.11 no.3
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• pp.247-253
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• 2002

Natural manganese ore was selected as main active component for a non-zinc desulfurization sorbent used in the gas clean-up process of the integrated gasification combined cycle (IGCC) because of excellent H$_2$S removal efficiency and economical aspect . In this study, the regeneration characteristics of sorbent after desulfurization reaction were determined in a thermobalance reactor and a fixed bed reactor in the temperature range of 350~55$0^{\circ}C$. The mixed gases of oxygen and nitrogen are used as the regeneration reaction gases for manganese sorbent. According to Mn-S-O phase diagram, the manganese sorbent has a low regeneration efficiency in medium temperature due to formation of MnSO$_4$ and the regeneration temperature must be over 85$0^{\circ}C$. To improve that problem, ammonia and steam was added in regeneration mixed gases. Effect of new regeneration method was determined by XRD and difference of desulfurization through multicycle tests.

• Clean Technology
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• v.2 no.1
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• pp.69-79
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• 1996

Sulfur emission control in coal gasification plants implies the removal of $H_2S$ from the fuel gas in the gas clean-up system. In this study, the effects of particle size of sorbents, temperature of sulfidation and sorbent characteristics on the $H_2S$ removal efficiency of manganese ore were investigated. Experimental results showed that the removal efficiency of $H_2S$ was optimum when the temperature was about $700^{\circ}C$. And that the smaller particle size, the higher the $H_2S$ removal efficiency, but that was not effective very much. As the temperature increases, the reactivity of sorbents has lowered because agglomeration of sorbents increased the intraparticle transport resistance. This phenomenon was confirmed by SEM photographs. The equilibrium ratio ($P_{H_2O}/P_{H_2S}$) obtained by experiments is represented as a ${\log}(P_{H_2O}/P_{H_2S})=5653/T-3.7909$. It was showed that the natural manganese ore could be used as a sorbent because its capacity for $H_2S$ removal is equivalent to the eariler developed sorbents.

• Clean Technology
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• v.23 no.2
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• pp.140-147
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• 2017

In this study, we performed numerical simulation for the catalyst regeneration process of diesel desulfurization reactor. We analyzed the changes in regeneration process according to purge gas flow rate, catalyst permeability, reactor size, and heat loss of reactor. We have found that the regeneration process is very much affected by temperature changes whereas it is hardly affected by catalyst permeability and porosity. We also estimated the regeneration time according to purge gas flow rate and initial temperatures and have found that increasing purge gas temperature is more effect for fast regeneration. The present results can be utilized to design a regeneration process of diesel desulfurization reactor for a fuel cell used in ships. Furthermore, the present work also can be used to design low sulfur diesel supply in oil refineries and therefore contribute to the development of clean petrochemical technology.

• 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.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.190-196
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• 2021

Desulfurization reaction in a bubble type reactor was carried out by adding three organic acids such as acetic acid, lactic acid, and antic acid to investigate the enhancement of the desulfurization performance of low-grade limestone. Desulfurization of limestone slurry without organic acids initiated to degrade at pH 5.2 or less, whereas organic acid-added limestone slurry exhibited a stable efficiency in the initial desulfurization with slurry pH ranging 4.2~4.5. At slurry pH below 4, the desulfurization performance of limestone slurry with addition of organic acids may be related to the amount of anions produced by dissociation of the organic acids. When limestone slurry had a large amount of anions, a rapid decrease in buffer capacity of slurry pH did not occur. These results were due to the acidity and dissociation of organic acids. The desulfurization performance of low-grade limestone slurry increased in the order of acetic acid (2.6%) < lactic acid (6.4%) < formic acid (16.7%).

• 한국생태학회:학술대회논문집
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• 1998.05a
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• pp.123.1-123.1
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• 1998

• 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$1.4{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$.

• Resources Recycling
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• v.14 no.2
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• pp.10-18
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• 2005

The manufacture property of anhydrous calcium sulfate (anhydrite Ⅱ) from flue gas desulfurization (FGD) gypsum discharged from domestic thermoelectric power plants to apply as an auxiliary material of cement and concrete by high temperature treatment were investigated. The FGD gypsum was completely converted to anhydrite Ⅱ at the temperature of 700$^{\circ}C$ and the retention time of 1 hr. In the phase transformation process, particle size was also changed. The chemical composition, particle size and heat property of anhydrite Ⅱ made from the FGD gypsum were similar to them of natural gypsum. In the leaching test of sulfate ion (SO$_4^{2-}$) at the temperature of 90$^{\circ}C$ and the retention time of 1 hr, the amount of leached SO$_4^{2-}$ for the anhydrite Ⅱ that was sintered at 700$^{\circ}C$ for 1 hr was about 50 wt.% based on that of natural gypsum. In addition, the amount of leached SO$_4^{2-}$ for the anhydrite Ⅱ by adding the slaked lime of 3 wt.% decreased about 70 wt.% comparing with that of natural gypsum. In the application test, the compressive strength of cement and concrete manufactured by using the anhydrite Ⅱ as an auxiliary material were similar or superior compared with them of cement and concrete done by natural gypsum as an auxiliary material.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.246-248
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• 2001

본 연구에서는 섬유상담체가 설치된 고정화 생촉매 air-lift bioreactor를 개발하여 HDS(hydrodesulfuriza tion)를 거친 디젤유를 대상으로 고심도 탈황을 시도하였다. 생촉매의 활성유지와 세포성장에 필요한 탄소원으로는 glucose보다 sucrose가 더 유리한 것으로 나타났다. 반복회분탈황반응을 통하여 약 60 시간 만에 디젤 중 황함량이 550ppm 에서 50ppm 이하로 감소되었다.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.549-552
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• 2000

A microorganism which can desulfurize dibenzothiophene (DBT) to 2-hydroxybiphenyl (2-HBP) was isolated from coal samples. The rate of DBT desulfurization was enhanced by the presence of yeast extract. In the case of DBT desulfurization by resting cells the rate and extent of 2-HBP production was enhanced with the addition of Tween 80.