CaO-SiO2-CaF2 슬래그에서 Sulfide capacity에 미치는 MgO와 Na2O의 영향 (초)

조문경,( Jin Cheng ),민동준 대한금속ㆍ재료학회 2009 대한금속재료학회 학술대회 개요집 Vol.2009 No.1

Desulfurization of coke oven gas using char-supported Fe-Zn-Mo catalysts: Mechanisms and thermodynamics

Jinxiao Dou,Xianchun Li,Arash Tahmasebi,Jing Xu,Jianglong Yu 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.11

Sulfidation properties of char-supported Fe-Zn-Mo sorbents prepared by ultrasonic impregnation method were investigated during simultaneous removal of H2S and COS from coke oven gas (COG) using a fixed-bed quartz reactor. Sorbent samples before and after sulfidation were analyzed using X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The experimental results showed that the addition of Mo significantly improved the desulfurization properties (i.e., breakthrough time, sulfur capacity and desulfurization efficiency) of Fe-Zn sorbents. Desulfurization reactions were exothermic and thermodynamically favorable in the temperature range of 200- 400 oC. Thermodynamic analysis of the sorbents indicated that higher concentration of H2S and lower concentration of H2 favors the reaction of metal oxides with H2S to form metal sulfides.

Thermodynamics of Copper Dissolution into MnO–SiO₂–MnS Inclusion System

Park, Jin Gyun,Park, Joo Hyun,Lee, Young Seok,Jung, Sung Mo,Min, Dong Joon The Iron and Steel Institute of Japan 2009 ISIJ international Vol.49 No.2

<P>Recently, a new process has been introduced to control α–γ transformation of steels using cuprous sulfide precipitates on the MnO bearing oxide inclusion as well as MnS. In order to optimize the composition of inclusions, the solubility of copper into MnO–SiO<SUB>2</SUB>–MnS system were measured at 1523 K and a dissolution mechanism of copper into an oxy-sulfide melts and cuprous sulfide capacity has been proposed. The solubility of copper increased with an increase in MnO/(MnO+SiO<SUB>2</SUB>) ratio and showed a maximum solubility at MnO and MnS doubly saturated composition, which was consistent with the maximum precipitation ratio of CuS. Deliberating an oxy-sulfide melts saturated with MnS, MnO, and SiO<SUB>2</SUB> at 1523 K, the phase diagram for the MnO–SiO<SUB>2</SUB>–MnS system indicated that the activity coefficient of cuprous sulfide in an oxy-sulfide melts was dependent on the activity of MnO and the activity coefficient of MnS. The dissolution mechanism of copper into a MnO–MnS inclusion system was confirmed and cuprous sulfide capacity was also defined from the reaction mechanism. Cuprous sulfide capacity for the MnO–MnS bearing inclusion strongly depends on stability of sulfide and basicity. The experimental results revealed that the optimized composition for inclusion to dissolve copper was (mass%MnO)=43.6, (mass%SiO<SUB>2</SUB>)=1.8 and (mass%MnS)=54.6. Consequently, it could be proposed that the harmlessness of copper in scrap and dispersion strengthening could be possible by using the non-metallic inclusion technique.</P>

Synthesis of Sb2S3 via Mechanochemical Milling and Its Application to Anode Material for Li-ion Battery

박창용,이혁재 사단법인 미래융합기술연구학회 2018 아시아태평양융합연구교류논문지 Vol.4 No.3

Antimony sulfide has a significantly higher theoretical capacity (946 mAh/g) as an anode material for Li-ion batteries than that of the widely used graphite (372 mAh/g), because antimony sulfide goes through a two-step electrochemical reaction with Li ions to complete a charge. In this study, the material and electrochemical properties of bulk antimony sulfide synthesized via dry vibration milling are investigated and compared with those of other commercially available antimony sulfide powders. We found that the synthesized antimony sulfide shows a finer and more spherical morphology than commercial antimony sulfide powders, which gives it higher charge-discharge capacities than the commercial antimony sulfide powders have. In particular, the cyclability of the synthesized antimony sulfide is much better than that of the commercial antimony sulfide when FEC additive is added to the electrolyte. The lithiation capacity at 50th cycle is ~450 mAh/g,

Hot Metal Desulfurization by CaO–SiO₂–CaF₂–Na₂O Slag Saturated with MgO

Cho, Moon Kyung,Cheng, Jin,Park, Joo Hyun,Min, Dong Joon The Iron and Steel Institute of Japan 2010 ISIJ international Vol.50 No.2

<P>The effect of CaF<SUB>2</SUB> and Na<SUB>2</SUB>O on the sulfide capacity of the CaO–SiO<SUB>2</SUB>–CaF<SUB>2</SUB>–MgO<SUB>satd.</SUB>(–Na<SUB>2</SUB>O) slags for hot metal desulfurization was investigated at 1623 and 1723 K by taking the role of MgO as an important refractory component into account. The liquidus line of the MgO-saturated system was similar to the CaO–SiO<SUB>2</SUB>–CaF<SUB>2</SUB> ternary slag system. The silica content for the 2CaO·SiO<SUB>2</SUB>-saturation was slightly decreased with MgO saturation. Although the sulfide capacity at MgO-saturation is lower than that of the CaO<SUB>satd.</SUB>–SiO<SUB>2</SUB>–CaF<SUB>2</SUB> slag system, it is greater than the ternary slag system saturated with 2CaO·SiO<SUB>2</SUB> phase. This suggests that MgO can increase the activity of free O<SUP>2−</SUP> ions under conditions of relatively low CaO activity. Near the composition of 3CaO·SiO<SUB>2</SUB>-saturation, MgO decreased the sulfide capacity of the slag because MgO is less basic than CaO in highly basic compositions. In addition, the addition of 5 mass% Na<SUB>2</SUB>O significantly increases the sulfide capacity of the MgO-saturated slag especially in the composition of low ‘CaO+CaF<SUB>2</SUB>’. This suggests that the input amounts of ‘CaO+CaF<SUB>2</SUB>’ can be reduced from 95 to 75 mass% for maintaining the sulfide capacity of 0.01 at 1623 K, which is important considering the reduction of CaO and CaF<SUB>2</SUB> consumption in hot metal desulfurization process with MgO saturation.</P>

Na2CO3 및 KIO3 첨착 왕겨활성탄의 H2S 흡착특성

김준석(Kim JunSuk),김명수(Kim MyungSoo) 한국유화학회 2002 한국응용과학기술학회지 Vol.19 No.3

Activated carbons with high surface area of 2,600 m2/g and high pore volume of 1.2 cc/g could be prepared by KOH activation of rice hulls at a KOH:char ratio of 4:1 and 850oC . In order to increase the adsorption capacity of hydrogen sulfide, which is one of the major malodorous component in the waste water treatment process, various contents of Na2CO3 and KIO3 were impregnated to the rice-hull activated carbon. The impregnated activated carbon with 5 wt.% of Na2CO3 showed improved H2S adsorption capacity of 75 mg/g which is twice of that for the activated carbon without impregnation and the impregnated activated carbon with 2.4 wt.% of KIO3 showed even higher H2S adsorption capacity of 97 mg/g. The improvement of H2S adsorption capacity by the introduction of those chemicals could be due to the H2S oxidation and chemical reaction with impregnated materials in addition to the physical adsorption of activated carbon.

KIO3 첨착활성탄의 황화수소 흡착 성능평가

김준석 ( Jun Suk Kim ),김명찬 ( Myung Chan Kim ),강은진 ( Eun Jin Kang ),김명수 ( Myung Soo Kim ) 한국유화학회 2003 한국응용과학기술학회지 Vol.20 No.1

N/A The impregnated activated carbons were prepared by the incipient wetness method with the contents of KIO_3 varied from 1.0∼10 wt% as the impregnation material. The specific surface area and micropore volume of the rice hulls activated carbon were 2,600∼2,800 m^3/g and 1.1∼1.4 cc/g, respectively. With increasing the contents of impregnation materials, the surface area and micropore volume decreased by 3∼21%. However, the amounts of hydrogen sulfide adsorbed increased by 2.1∼2.8 times depending on the impregnation content. The optimum contents of KIO_3 were2.4 wt%. although the breakthrough time and adsorption capacity of hydrogen sulfide decreased with increasing temperature in the case of the unimpregnated activated carbons, they increased by 1.2∼3.2 times for the case of the impregnated activated carbons. The optimum aspect ratio(L/D) was 1.0 and the adsorption amount of hydrogen sulfide enhanced with increasing the gas flow rate. The regeneration temperature was determined as 400℃ from the TGA experiment. The adsorption capacity of hydrogen sulfide with the impregnated activated carbon decreased gradually as the regeneration continued. The hydrogen sulfide adsorption amount of the regenerated activated carbon up to 4 times was still higher then that of the unimpregnated activated carbon.

생물탈취용 담체별 흡착 제거능 비교 연구

박상진 우송대학교 2000 우송대학교 논문집 Vol.5 No.-

Hydrogen sulfide(H₂S) and ammonia(NH₃) are the main malodorous gases emitted from various industrial areas and wastewater, night soil, and animal waste treatment plants. To remove these gases, physico-chemical methods like adsorption, chemical scrubbing have generally been used. However, a biological method, which uses microbial activities for the degradation of malodorous gases, has drawn attention as more economical alternatives. To develop the effective technology of biological deodorization, it needs that the efficient microbial carriers should be selected and that design parameter including operation parameter should be studied. In this study, odor removal test by adsorption and biological degradation were carried out for 6 filter material which are activated carbon, ceramic, wood-charcoal, earthworm cast, slag, saran net. At first, 6 material's removal capacity by adsorption for single and binary gases mixed with H₂S and NH₃were studied. The experimental result is as follows. Although it has some difference among each materials, treat ability of binary gases mixed with H₂S and NH₃were lower than that of single gas in two experiments which are odor removal test by adsorption and biodegradation. Earthworm cast and wood-charcoal were very effective material to remove NH₃and H₂S respectively as a single odor. Adsorption capacity of earthworm cast for NH₃single odor is 2.35 g- NH₃·㎏ dry wt-¹·d-¹and the one of wood-charcoal for single gas of H₂S is 3.29 g- H₂S·㎏ dry wt-¹·d-¹. But ceramic has shown the best removability to treat odor of H₂S and NH₃as a single odor and binary mixed odor. Adsorption capacity of ceramic for NH₃single odor is 3.26 g-NH₃·㎏ dry wt-¹·d-¹and the one of wood-charcoal for single gas of H₂S is 2.3 g- H₂S·㎏ dry wt-¹·d-¹. Although H₂S and NH₃are typical odorants at industrials fields and it occurs simultaneously in general, most of research have accomplished for the study on odor removal of single gas focused on academic aspect not practical use. The results obtained from this study are valuable to develop the facility of biological deodorization because this research were carried out for mixed odor including single odor together and for the practical design parameter.

Soft‑template‑assisted synthesis of N‑doping layered CoS2 nanoparticles as an advanced anode for sodium‑ion batteries

Danyang Han,Guo Yu,An Liu,Gangyong Li,Wei Wang,Binhong He,Zhaohui Hou,Hong Yin 한국탄소학회 2023 Carbon Letters Vol.33 No.6

As a promising anode for sodium-ion batteries (SIBs), cobalt sulfide ( CoS2) has attracted extensive attention due to its high theoretical capacity, easy preparation, and superior electrochemical activity. However, its intrinsic low conductivity and large volume expansion result in poor cycling ability. Herein, nitrogen-doped carbon-coated CoS2 nanoparticles (N–C@ CoS2) were prepared by a C3N4 soft-template-assisted method. Carbon coating improves the conductivity and prevents the aggregation of CoS2 nanoparticles. In addition, the C3N4 template provides a porous graphene-like structure as a conductive framework, affording a fast and constant transport path for electrons and void space for buffering the volume change of CoS2 nanoparticles. Benefitting from the superiorities, the Na-storage properties of the N–C@CoS2 electrode are remarkably boosted. The advanced anode delivers a long-term capacity of 376.27 mAh g? 1 at 0.1 A g? 1 after 500 cycles. This method can also apply to preparing other metal sulfide materials for SIBs and provides the relevant experimental basis for the further development of energy storage materials.

Spectrophotometric Determination of Maximum Loading Capacity of a Dendrimer

전영진 대한화학회 2023 대한화학회지 Vol.67 No.4

A series of hydrophobic dodecyl-terminated 6th-generation poly(amidoamine) dendrimer (H)-encapsulated cadmium sulfide ((CdS)n@H) nanoparticles in a co-solvent (toluene: methanol = 6.8: 3.2 v/v) are synthesized. The diameters of CdS nanoparticles within the dendrimer were estimated by analyzing the positions of the first excitonic absorption peaks of CdS in UV-vis spectra. The size of the CdS nanoparticle within the dendrimer shows a saturation value as the CdS/H ratio (n) increases, which is believed to be due to the limited physical size of the void cavity within the dendrimer. This simple and convenient method of estimating the saturation of the size of CdS in dendrimers may be useful in determining the maximum void space within other dendrimers under various solvent conditions.