• KSBB Journal
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• v.14 no.1
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• pp.45-50
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• 1999

This study was focused on investigating the growth properties of a sulfate reducing bacterium Deslfovibrio sp. B5 which has metabolic ability for desulfurization of petroleum. The optimal temperature and pH for growth of Desulfovibiro sp. B5 were $38^{\circ}C$ and 6.6-7.0, respectively. Addition of 10% corn steep liquor to the Postgate medium C resulted in 0.79 g/L cell concentration, corresponding to a 1.8-fold increase in dry cell mass. Acetate concentrations above 10g/$\ell$ inhibited cell growth significantly. $H_2S$ generated from the sulfate reduction also inhibited the growth of Desulfovibrio sp. B5 at a concentration of 10mM total sulfide. But $N_2$ gassing relieved the growth inhibition by $H_2$S and thereby resulted in a 1.75-fold enhancement in specific growth and lactate consumption pattern of Desulfovibrio sp. B5.

• Clean Technology
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• v.8 no.1
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• pp.11-17
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• 2002

Petcokes is the final product obtained from a refinery process. This petcokes includes high percentage of inorganic and sulfur compounds. Currently, the petcokes produced from domestic refinery plants include more than 6% of sulfur. To use petcokes as valuable raw materials, the weight percentage of sulfur must be lower than 2% of sulfur. Solvent extraction, thermal desulfurization, and hydro-desulfurization have been used to remove the sulfur. In this study, we attempted new approach to remove the sulfur introducing microwave energy. Microwave increase the reaction rates by providing the fast heating and disconnecting the bonding structure of the molecules. The experiments of microwave thermal desulfurization and microwave plus hydrogen gas were carried out to remove the sulfur. We obtained 68.3% of sulfur removal rate with the 2 hours of reaction time and 1835 W of microwave powder. In the experiment of microwave with hydrogen gas, we obtained 86.4% of sulfur removal rate with the 1.5 hours of reaction time and 1835 W of microwave power. If we increase reaction time or decrease the particle size of petcokes, we expect more than 90% of sulfur removal.

• Journal of Microbiology and Biotechnology
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• v.1 no.1
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• pp.1-5
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• 1991

Sulfate-reducing bacteria have been isolated from soil and their abilities to degrade dibenzothiophene (DBT) were compared with those of type cultures. Among the strains tested a soil isolate M6 showed the highest ability to degrade DBT. Isolate M6 was characterized as a mesophilic obligatory anaerobe. The morphology of the bacterium was vibrioid with the size of $0.4-0.7{\;}\mu\textrm{m}{\;}by{\;}1.0-1.5{\;}\mu\textrm{m}$. Gram reaction was negative and nonsporulating. Desulfoviridin is present. Lactate, pyruvate, ethanol and malate supported growth of the bacterium in the presence of sulfate. Sulfate, sulfite, thiosulfate and sulfur served as electron acceptors for growth. Hydrogenase was present. The mol% of guanine and cytosine of DNA was determined as 56%. The bacterium produced viscous material. From these results, the isolate M6 was identified as Desulfovibrio desulfuricans.

• Clean Technology
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• v.16 no.1
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• pp.1-11
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• 2010

As crude oil with heavier and/or highly oxidized components prevails, purification technologies such as desulfurization, denitrilization and demetalization have become important issues to control contents of sulfur and other impurities affecting the quality of petroleum. Also, the importance of catalyst technologies related with crude oil purification has been emphasized to control the production and yield of products. In this paper, technology trends of impurity removal such as sulfur, nitrogen and metal components from crude oil and catalysts related with purification of crude oil were studied through patent analysis. The patents published or registered in Korea, U. S. A., Japan, and Europe from mid 1970's to 2009 had been analyzed based on the application tendency, the distribution of major applicants, and their active indices, etc. The technology flow was figured out to see the technology trends.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.537-542
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• 1999

Removal of sulfur compounds in the petroleum products is essential for the prevention of sulfur oxides. However, conventional methods involving catalytic reactions are found to have some limitations in complete removal of harmful sulfur compounds and to require relatively high cost. Recently, desulfurization process using microorganisms is known to be promising in terms of excellent sulfur removal efficiency and reasonably low treatment cost. For the biodesulfurization process to be effective, the solubilization of sulfur compounds into aqueous solution is a prerequisite. In this study, polyoxyethylene nonionic surfactants were used in order to enhance the solubilization of sulfur spectrophotometer. The solubilization of sulfur compounds was found to increase with temperature and to bo abruptly increased at above 1 wt % surfactant solutions. It was also observed that the longer the hydrophobic chain of the surfactant molecule, the higher solubilizing power of a nonionic surfactant. It was found that the Tergitol series surfactants showed higher solubilizing capacity than Neodol series presumably due to the disruption of the regular packing in the hydrocarbon region of the surfactant aggregates.