Sulfur Absorption Research Articles

Metal Oxide Nanoparticles Embedded in Porous Carbon: Material Evolution During Sulfur Absorption Under Hydrothermal Conditions

Metal Oxide Nanoparticles Embedded in Porous Carbon: Material Evolution During Sulfur Absorption Under Hydrothermal Conditions

Proposing a suitable slag composition by estimating the fusion behavior, viscosity and desulphurization ability for blast furnaces running with high alumina

The present work was focused on identifying a suitable quaternary CaO-MgO-SiO2-Al2O3 high alumina slag for blast furnaces running with high alumina ores as an input raw material. These high alumina slags have inferior properties like high liquidus temperature, high viscosity and poor sulphur absorption capacity. These properties will hamper the working condition of the blast furnace as well as quality of hot metal produced. To overcome these issues, it is necessary to focus on selecting an appropriate slag composition having superior properties like, minimum difference between softening and flow temperature (ST & FT) (<100 °C), low liquidus temperature, good fluidity (i.e. viscosity <0.6 pas. at 1773 K) & high sulphur absorption capacity at 1773 K. In the current work various slag compositions having Al2O3 25–30 %, CaO/SiO2 ratio (0.8–1.6), and MgO (8–16 %) has considered for determining fusion temperature, viscosity and desulphurization ability of slag using high temperature microscope, viscometer and slag-metal Desulphurization experiments. It was found that slag with Al2O3 (30 %) and C/S ratio (1.2) coupled with MgO (12 %) is showing superior properties like low FT-ST (i.e. short slag) having viscosity 0.35 pas and Desulphurization ability of approx. 80 % at 1773 K which fulfills the necessary conditions for better working condition of the blast furnace.

Regeneration and sulfur recovery of Lanxess Lewatit AF 5 catalyst from the acidic Albion leaching process using toluene and tetrachloroethylene as organic solvents

The removal of elemental sulfur from the final leach residue produced during the atmospheric oxidative leaching of chalcopyrite concentrates is both a technical and an economic challenge. Lanxess Lewatit® AF 5 catalyst is a promising candidate material that can collect this elemental sulfur during the leaching process. However, to be cost-effective it is necessary to develop methods to regenerate and recycle the AF 5. In the present research, toluene and tetrachloroethylene were studied as potential organic solvents for the removal of the sulfur from the sulfur loaded AF 5. Also, the recovery of elemental sulfur from the resulting liquor was investigated. The effects of temperature, time and AF 5 to solvent ratio on sulfur removal from the sulfur loaded AF 5 were examined. The optimum desulfurization conditions were 100 °C for toluene and 110 °C for tetrachloroethylene for an AF 5 to solvent ratio of 1:50 and a processing time of 120 min. For toluene and tetrachloroethylene, the sulfur removals were 89.8% and 88.1%, respectively. Toluene was considered to be the most promising solvent due to its higher sulfur removal efficiency and a reduced effect on the behavior of the recycled AF 5 in the leaching process. After three consecutive leaching and regeneration cycles the sulfur absorption capacity and the copper and iron leaching recoveries were essentially unchanged. Copper and iron recoveries of greater than 95% and greater than 80%, respectively, were achieved with the recycled AF 5.

Poly (4,4'-methylenedianiline)-graphene oxide nanocomposite: synthesize and application in removal of benzothiophene from model liquid fuel.

The adsorption of sulfur-containing compounds from fuels on polymer nanocomposite adsorbents modified with carbon-based materials was investigated. This work reports the removal of benzothiophene from the model liquid fuel using a novel adsorbent prepared by nanopoly (4,4'-methylenedianiline)-graphene oxide (NPMDA/GO) composite. The adsorbent was successfully synthesized with the in situ electrochemical method and characterized using thermal gravimetric analysis (TGA), field-scattering scanning electron microscopy (FE-SEM), transient electron microscopy (TEM), X-ray diffraction analysis (XRD), and Fourier transform infrared (FTIR). The results showed that the presence of graphene oxide (GO) nanosheets in NPMDA/GO composite adsorbent due to its high tendency to sulfur would increase the adsorption of benzothiophene compared to unmodified nanopoly (4,4'-methylenedianiline) (NPMDA). The π_complexation, oxygenated organic functional groups, and layered sheets of graphene oxide improve adsorption capacity for desulfurization. The NPMDA/GO composite presented maximum efficiency (63.33%) at 30mg/L initial concentration, 120mg adsorbent dose, and 120min contact time at 25°C. Furthermore, the adsorbent shows an almost good reusability after four cycles (67.12mg/g sulfur absorption capacity). Pseudo-second-order model (R2 = 0.9975) and the Freundlich isotherm (R2 = 0.8813) were used to describe the adsorption process. Findings confirm that NPMDA/GO composite can be applicable for removal of benzothiophene from liquid fuels.

Modeling of the Resonant X-ray Response of a Chiral Cubic Phase

The structure of a continuous-grid chiral cubic phase made of achiral constituent molecules is a hot topic in the field of thermotropic liquid crystals. Several structural models have been proposed so far. Resonant X-ray scattering (RXS), which gives information on the molecular orientation in the unit cell, could be applied to select the most appropriate model. We modeled the RXS response for the recently proposed chiral cubic phase structure with an all-hexagon chiral continuous grid. A tensor form factor of a unit cell is constructed, which enables calculation of intensities of peaks for all Miller indices. We find that all the symmetry allowed peaks are resonantly enhanced, and their intensity is much stronger than the intensity of the symmetry forbidden (resonant) peaks. In particular, we predict that a strong resonant enhancement of the symmetry allowed peaks (011) and (002), not observed in a nonresonant scattering, could be observed by RXS at the carbon absorption edge. By RXS at the sulfur absorption edge, one might observe a resonant peak (113) and resonantly enhanced peak (233), and resonant enhancement of all the peaks that are observed in a nonresonant scattering, which probably hide the rest of the predicted resonant peaks.

Role of sulphur in pulse crops: A review

Sulphur is essential nutrient for every living cell; it is component of 21 amino acids which form protein. It is fourth key plant nutrient after nitrogen, phosphorus and potassium. Pulses are particularly sensitive to sulphur deficiency which gives low quality and less yields. sulphur plays a key role In chlorophyll and oil synthesis. Plants uptake sulphur only in sulphate form (so42-) and it reduces to form sulphur containing amino acids and other compounds. Application of sulphur increases the nitrogen use. Efficiency of N, P, K is seriously affected under sulphur deficiency. Field experiments in many agro climatic conditions shown that application of 30 and 40 kg S/ha-1 along with recommended dose given the highest yields and protein content in pulses. Moreover, this review highlights the availability of sulphur for profitable crop production, effects of different sources and levels of sulphur in pulse crops, effect of sulphur on various parameters and it also includes the sulphur absorption and translocation in plants. Moreover this review provides new sights to revisit the sulphur significance in pulse crops.

Artificial intelligence applied to model the sulphur absorption process - a possible application in cure with sulphurous mineral water

The presence of Sulphur in human body is estimated to be around .25 percent from total body weight. The modern therapy includes among others the usage of Sulphur us spring waters as crenotherapy or external use like - therapeutic and preventive treatment for a large category of diseases. High levels of hydrogen sulphide are extremely toxic and as result the model of absorption of Sulphur could be useful as predictor in a daily treatment during a cure with sulphurous mineral water. This quantity of chemical elements from a specific diet rich in these elements absorbed in human organism is one of the most important characteristics of a benefic cure in medical diseases. The most studied mechanisms of absorption were studied for Zinc, Magnesium, Iron and Calcium. The most common way to develop a mathematical model is to use the pharmacokinetic equations based on Michaelis-Menten approach (first order model) and to develop it thereafter for quantitative relations. In some cases, only experimental data can exists and the pharmacokinetic model is not completely elucidated or a simplified model doesn’t exist yet. A model based on genetic programming is proposed in order to discover a mathematical relationship between dietary sulphate (mmol/day) and total sulphate in ileostomy fluid (mmol/day) using experimental data published in literature. The set of terminals that are used in genetic programing – GP (using Polish notation) is reduced to basic operation (sum, difference, multiplication and division) along with the most plausible operations that could have physical meaning: rooted square, exponential and power. The formulas discovered by GP using experimental proved a good fit of data with discovered mathematical formula, e.g. the rooted mean square error below 1.5% and R2  94.36%. Mathematical formulas discovered by genetic programming can be used as an alternative to pharmacokinetic model in order to predict sulphate and sulphite absorption and excretion. The usage of this method is especially efficient when the mechanism of absorption in not elucidated enough to provide a compartmental model given by a set of equations. A correlation with pharmacokinetic equations in the case that these exist will help the improvement of terminals and alphabet used by genetic programming in order to have a model closer to one that have a physical meaning

Regeneration Mechanism of Sulfur Absorption Via Samarium-doped Cerium Adsorbents in the Gas Atmosphere of O2/N2.

Sulfides existing in many high-temperature gas mixtures have a negative effect on various industrial applications. Ce-based adsorbents are becoming a hotspot in the high-temperature desulfurization process owing to their excellent thermal stability at high temperatures and regeneration capacity. In this study, we investigate the regeneration path of samarium-doped cerium (SDC) sorbent at high temperature. The SDC adsorbent showed a good sulfur removal ability and excellent regeneration capacity. Ce2O2S and Ce(SO4)2 are observed in the used adsorbent, and Ce2O2S is the main sulfur-containing species. The regeneration path of the Ce2O2S is the key to the regeneration mechanism of the adsorbent. There are two regeneration paths for the Ce2O2S at high temperature in O2/N2 gas mixture. In air stream, the Ce2O2S is oxidized to Ce2O2SO4 and then decomposes into CeO2 and SO2. In a 2% O2/N2 gas condition, the Ce2O2S directly generates CeO2 and elemental sulfur with O2 assistance.

Improvement on Sulfur Capacity of Cu-Al-Based Desulfurization Sorbents with Various Transition Metal Additives for Coal Derived Synthetic Gas Cleaning.

This study examined the effects of additives to improve the COS absorption capacity of Cu-Al-based sorbents for the integrated gasification fuel cell (IGFC) process. To absorb a small amount of COS, an Al-based precursor was added to the precursor solution for Cu-Al-based sorbents because a high surface area absorber was required. Various transition metals (Zn, Fe, Mn) were used as additives to improve the stability of the Cu-Al-based absorbent. The changes in surface properties and sulfur absorption capacity of the Cu-Al-based absorbent were investigated according to the composition of transition metals. As a result of the sulfur absorption test, the difference in the sulfur absorption capacity of the Cu-based sorbents was confirmed depending on the type of additive, and changes in their surface area. Moreover, the pore characteristics were observed by the nitrogen adsorption method. Sorbents with high surface areas generally have high sulfur capacity, but the additive component has a strong effect. These results can be explained by the transition metal additive binding to Cu to form a composite metal oxide. Furthermore, manganese was found to be suitable for improving the stability and surface area of the copper-based absorbent.

Sulfur-linked cyanobiphenyl-based liquid crystal dimers and the twist-bend nematic phase

ABSTRACTThe synthesis and characterisation of two series of cyanobiphenyl-based liquid crystal dimers containing sulfur links between the spacer and mesogenic units, the 4ʹ-[1,ω-alkanediylbis(thio)]bis-[1,1ʹ-biphenyl]-4-carbonitriles (CBSnSCB), and 4ʹ-({ω-[(4ʹ-cyano[1,1ʹ-biphenyl]-4-yl)oxy]alkyl}thio)[1,1ʹ-biphenyl]-4-carbonitriles (CBSnOCB) are described. The odd members of both series show twist-bend nematic and nematic phases, whereas the even members exhibit only the nematic phase. An analogous cyanoterphenyl-based dimer, 34-{6-[(4ʹ-cyano[1,1ʹ-biphenyl]-4-yl)thio]-hexyl}[11,21:24,31-terphenyl]-14-carbonitrile (CT6SCB), is also reported and shows enantiotropic NTB and N phases. The transitional properties of these dimers are discussed in terms of molecular curvature, flexibility and biaxiality. The same molecular factors also influence the birefringence of nematic phases. Resonant X-ray scattering studies of the twist-bend nematic phase at both the carbon and sulfur absorption edges were performed, which allowed for the determination of critical behaviour of the helical pitch at the transition to the nematic phase, the behaviour was found to be independent of molecular structure. It was also observed that despite the different molecular bending angle and flexibility, in all compounds the helical pitch length far from the N-NTB transition corresponds to 4 longitudinal molecular distances.

ChandraX-ray spectroscopy of the focused wind in the Cygnus X-1 system

We present an analysis of threeChandraHigh Energy Transmission Gratings observations of the black hole binary Cyg X-1/HDE 226868 at different orbital phases. The stellar wind that is powering the accretion in this system is characterized by temperature and density inhomogeneities including structures, or “clumps”, of colder, more dense material embedded in the photoionized gas. As these clumps pass our line of sight, absorption dips appear in the light curve. We characterize the properties of the clumps through spectral changes during various dip stages. Comparing the silicon and sulfur absorption line regions (1.6–2.7 keV ≡ 7.7–4.6 Å) in four levels of varying column depth reveals the presence of lower ionization stages, i.e., colder or denser material, in the deeper dip phases. The Doppler velocities of the lines are roughly consistent within each observation, varying with the respective orbital phase. This is consistent with the picture of a structure that consists of differently ionized material, in which shells of material facing the black hole shield the inner and back shells from the ionizing radiation. The variation of the Doppler velocities compared to a toy model of the stellar wind, however, does not allow us to pin down an exact location of the clump region in the system. This result, as well as the asymmetric shape of the observed lines, point at a picture of a complex wind structure.

Investigation of sour gas desulfurization process by nano absorber and under magnetic field in a packed tower; experimentally and theoretically

ABSTRACTHydrogen sulfide is a major contaminant that is expelled into the atmosphere by chemical industry. So, the mechanism for absorption of sulfur from sour gas by carbon nano-tubes in a packed bed under a magnetic field is considered, in this paper. Therefore, empirical and theoretical studies have been done to obtain the sulfur content in the outlet gas stream. The independent variables studied in this paper include: the magnetic field (1.5 amperes), initial sulfur content (0, 0.003, 0.008, 0.013, 0.05 and 0.1 mole/m3) and gas temperature (33°C, 37°C and 40°C). The gas flow rate is (0.18, 0.2 and 0.22 m3/min). The minimum amount of hydrogen sulfide in the output stream is selected as the aim of the experiments and related conditions as optimal operating conditions. Results indicate that the sulfur oxidation curves contains an approximately linearly increasing segment when the applied field intensity increases from 90 to 160 Oe, and that the sulfur oxidation percentage is improved by nearly 5.8% when the magnetic field is increased from 90 to 400 Oe. Obtained results state the optimum flow rate and temperature for maximum desulfurization is 0.22 m3/min and 40°C, respectively. Results show, the increase in the initial concentration under the operating temperature and magnetic field increases the effective mass transfer coefficient from 2.2–8.3. In addition the effective mass flux of hydrogen sulfide removal can be extended to 5.9, in this state. Finally, the experimental results have a fairly good fit with theoretical results.

Calculation of a packed column for absorption of hydrogen sulfur from gases formed by separation of crude oil

According to the well-known calculating algorithm for the packed absorption column, the main technological parameters and geometric dimensions of the apparatus for hydrogen sulfide containing gases, formed during the separation of crude oil, are determined. A 2,5-n solution of monoethanolamine is selected as the absorbent. Comparative results of the calculations are showing, that the working pressure in the column should be 4 atm, since with their lower values, the flow rate of the absorbent and the size of the column are increasing. The increase in working pressure is impractical, since it will require a transition from centrifugal and compresses pumps to piston pumps. ∏ The obtained parameters were compared for an absorption column in which the flow structure of the gas and liquid phases corresponds to ideal displacement, with the calculation results when the flow structure in the gas phase corresponds to the ideal displacement mode (as in the standard calculation algorithm) and in the liquid phase to ideal mixing. It is shown that, with the Peclet number of longitudinal diffusion pe&lt;40 the height and volume of the column increases by 10 and more percent and should be taken into account when packed columns, intended for absorption processes, are designed. At pe=30 the height and volume of the nozzle in the column increases by 27%. Another feature of the modelling and calculation of devices is a spike in concentration, meaning, that the lower part of the working line will cross the equilibrium. Calculations in thisparticular case show that at ≈ 11 the working line crosses the equilibrium and theoretically column height and volume →∞.

Sunflower Seedlings Hyperaccumulate Selenium

Selenium (Se) is an essential element for animals and humans, but not plants. However, the capacity of some plants to accumulate and transform Se into bioactive compounds has important implications for human nutrition and health. In this study, sunflower (Helianthus annuus) and maize (Zea mays) seedlings were cultivated in soil to investigate the effect of different rates of sodium selenite (1–90 mg kg−1 soil) and sodium selenate (1–30 mg kg−1 soil) on absorption and translocation of Se and sulphur (S). Sodium selenate decreased growth of sunflower roots at all applied rates and of maize roots at the highest rate applied. In contrast, sodium selenite up to 30 mg kg−1 for sunfower and 3 mg kg−1 for maize resulted in increased shoot and root growth. An increase in Se concentration in soil resulted in an increase in Se and a decrease in S accumulation in roots and shoots of both maize and sunflower. Selenium translocation from roots to shoot was higher in sunflower than maize. Root-to-shoot translocation of Se was 5 to 30 times greater in sunflower and 0.4 to 3 times greater in maize in the sodium selenate than sodium selenite treatments. Sunflower, as a Se-hyperaccumulator with up to 1.8 g kg−1 in shoots (with no significant decrease in shoot biomass) can be a valuable plant in biofortification to improve animal/human nutrition, as well as in phytoremediation of contaminated sites to restore ecosystem services.

Variation in the Determination of Macronutrient Absorption by Micronutrients in Certain Stionic Combinations of Grape

Investigations were carried out through a survey of vineyards of Thompson Seedless and 2A clone on their own root and Dog Ridge rootstock to identify those micronutrients which have positive relationship with major nutrient absorption and the stionic combinations in which such relationship exists. Relationship of major nutrient absorption with micronutrient status was highly complex, which could be attributed to variation in their absorption due to their relative abundance, variety and rootstock, and interactions among them. Results of the investigations indicated that none of the micronutrients could influence the absorption of N in any stionic combination. Fe, Mn, Zn and Cu together determined the absorption of Na highest in 2A clone on Dog Ridge rootstock, followed by the determination of P and S in Thompson Seedless on Dog Ridge. Mn contributed most towards the determination of P, K, Ca, Mg, S and Na across the stionic combinations. P absorption increased with higher levels of Mn and Cu respectively above 66.0 and 111.9 ppm, but decreased above 121.1 ppm of Zn in TS/DR. It increased with increasing levels of Mn above 129.8 ppm in 2A/OR and Zn levels above 121.2 ppm in 2A/DR. Higher levels of petiole Cu above 105.4 ppm and of Mn below 435.9 ppm increased K absorption in TS/DR. Levels of Mn above 210.2 ppm in 2A/OR, of Cu above 155.6 ppm and Mn at any level in 2A/DR were also associated with higher absorption of K. Calcium absorption increased with Fe levels above 116.7 ppm and Mn levels above 106.3 ppm in TS/OR. The increase in Ca absorption was limited to 466.7 and 500 ppm respectively of Fe and Mn in 2A/DR. Fe levels above 100 ppm resulted in increased Ca absorption in 2A/OR. Increased Mg absorption was associated with petiole Zn levels above 65.2 ppm in TS/OR, with any level of Mn and Zn levels up to 96.7 ppm in 2A/OR. It also increased with Zn levels above 112.9 ppm, but Mn levels up to 650 ppm in 2A/DR. Sulphur absorption increased with increasing contents of petiole Mn to any level and Cu levels above 149.3 ppm, but its increase was limited to 118.8 ppm of Zn in 2A/OR. Reduced absorption of Na was associated with increasing levels of Mn above 209.6 ppm in TS/OR, and with increasing levels of Fe, Mn and Zn respectively above 63.6, 257.1 and 117.1 ppm in 2A/OR. Increasing levels of Fe an Mn respectively above 516.6 and 380.8 ppm, but Zn levels below 66.7 ppm also reduced Na absorption in 2A/DR. Management of micronutrient levels above their threshold levels and below optimum levels corresponding to major nutrient absorption could help in increased absorption of P, K, Ca, Mg and S but reduced absorption of Na in different stionic combinations.

Examination of Correlation between Histidine, Sulfur, Cadmium, and Cobalt Absorption by Morus L., Robinia pseudoacacia L., and Populus nigra L.

ABSTRACTWe investigated the relationship between histidine, sulfur (S), cadmium (Cd), and cobalt (Co) in three hyperaccumulating plants, namely Morus L., Robinia pseudoacacia L., and Populus nigra L. The samples were collected around Gaziantep and Bursa cities because these two cities have more than 1,500,000 populations, in Turkey, as well as they are highly industrialized. Analyses for Cd, Co, and S were done by inductively coupled plasma mass spectrometer (ICP-MS) and for histidine by high-performance liquid chromatography-mass spectrometer (HPLC-MS). Related with role of histidine in detoxification, it was considered that histidine did not bind nickel (Ni) directly in the cytoplasm, but in transport vesicles because metal-rich vesicles had been observed in the cytoplasm of cells of hyperaccumulator plants. The linear correlations were rhis-Cd = 0.70 and rhis-Co = 0.74 for P. nigra L., rhis-Co = 0.52 and rCo-S = 0.76 for R. pseudoacacia L. It was concluded that P. nigra L. leaves can be considered as hyperaccumulators.

Sulfur poisoning and attempt of oxidative regeneration of La0.75Sr0.25Cr0.5Mn0.5O3−δ anode for solid oxide fuel cell

Sulfur poisoning and subsequent oxidative regeneration of La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCrM) anode by pure O2 were studied using a model solid oxide fuel cell with yttria-stabilized zirconia (YSZ) electrolyte. Utilization of H2 fuel containing 50 ppm (v) of H2S was found to result in increasing polarization resistance of LSCrM anode and degradation of overall cell performance, mainly due to absorption of sulfur and formation of metal sulfides. The electrochemical performance of the cell can be recovered after first two poisoning-oxidative regeneration cycles. Oxidative treatment made it possible to remove the absorbed sulfur and to oxidize metal sulfide. Progressing microstructure changes in LSCrM anode with increasing number of alternative poisoning-regeneration cycles lead however to irreversible degradation.

Metal particulate-containing conformal coatings for improved IT hardware reliability in harsh environments

A method to overcome IT hardware corrosion-related failures in geographies with highly concentrated atmospheric pollution is presented. Metal particulate was incorporated into a standard silicone conformal coating to form composite materials in which the metal particulate acts as a sacrificial material to react with elemental sulfur. Metal particulates (copper and silver) were chosen based on their strong propensity to corrode in sulfur-rich environments. Through absorption of sulfur into silicone composites, the metal particulate is able to react to form either copper sulfide or silver sulfide before reaching the underlying metallic architectures, thus preventing failures. This approach resulted in up to a ~123% life improvement of the coated component over that of a standard silicone conformal coating. In addition, this approach has shown that the sacrificial material can slow the rate of metal sulfide formation at the metallic interface of thick-film surface mount resistors. The metal particulate-containing conformal coatings developed here overcome many limitations brought about by the use of non-silicone conformal coatings, potentially leading to its incorporation into IT hardware to prevent metallic corrosion of components in harsh environments.

Desulfurization Behavior and Mechanism of CaO-saturated Slag

To develop a high-efficiency desulfurizer for the production of pipeline steel with the LD-RH-CC process, the desulfurization efficiency and mechanism of CaO-saturated slag were studied using a vacuum-induction furnace and Si-Mo electric resistance furnace. The results show that the desulfurization ability for slag with a small amount of solid CaO was highly enhanced under conditions of satisfied kinetics. The desulfurization reaction of CaO-saturated slag depended on the liquid slag rather than the solid CaO, as sulfur was not detected inside the solid CaO. The desulfurization efficiency of CaO-saturated slag was also influenced by the amount of residual liquid slag and its sulfur absorption ability. The sulfur absorption ability of CaO-CaF2 slag was analyzed to be much higher than that of CaO-Al2O3-CaF2-(SiCO2) slag. Moreover, the effect of solid CaO on the desulfurization kinetics was evaluated and the application conditions of CaO-saturated slag were discussed.

High Capacity Li-S Secondary Battery Using Vertically-Aligned CNT Electrode

In recent years, the lithium-sulfur (Li-S) secondary battery has been energetically researched worldwide as a good candidate for next-generation secondary batteries. The sulfur active material has a theoretical capacity of 1675 mAh g-1and is abundant and highly inexpensive. However, several issues are associated with the use of Li-S secondary batteries, such as low utilization due to the insulating property of sulfur and the redox shuttle phenomenon caused by the dissolution of polysulfides generated during the discharge process. In the present work, we have developed a Li-S secondary battery using the carbon nanotube (CNT) technoloy. Multiwalled-CNTs were directly grown on a nickel current collector by using the thermal chemical vapor deposition (CVD) method. The CNT films were used as the electrode for the Li-S battery. The S-CNT cathode was fabricated by impregnating it with molten sulfur. Then, sulfur powder was uniformly placed on the CNT film and heated at more than the melting point of 113°C. Our CNT has a diameter of 10-15 nm and a length of 200-600 µm. Therefore, the CNT electrode has a wide reaction area owing to its large specific surface area. In addition, the active materials can react rapidly because the electrons quickly access through the CNTs that connect directly with the current collector. At IMLB 2014, we reported that coin-cell-type Li-S batteries with a sulfur loading of up to 10 mg cm-2 operate at a current density of 0.5 mA cm-2 [1]. However, more sulfur loading is required, in order to achieve the electrode capacity of 300 Wh kg-1 for practical usage. As sulfur loading increased to more than 10 mg cm-2, the discharge capacity decreased dramatically, probably owing to be attributed to inhomogeneous sulfur distribution in the CNT film. Moreover, the CNT films fell off the nickel current collector because of the shrinkage of the CNT bundles owing to the absorption of sulfur. Therefore, we attempted to synthesize harder CNT films with homogeneously impregnated sulfur. A thick amorphous carbon layer was coated on the CNTs by optimizing the thermal CVD process, thus making the CNT films harder. Moreover, the adhesiveness between the CNTs and the nickel current collector was enhanced, which improved CNT exfoliation. For homogeneous distribution, sulfur impregnation was performed in vacuum. The sulfur was considered to spread over the CNT films more uniformly. We could obtain the stable coin-cell-battery performance with sulfur loading of up to 20 mg cm-2, and the capacity was estimated to be more than 300 Wh kg-1 [2]. We manufactured 1 Ah-class pouch cell, with electrode surface area of 50 cm2. Reference [1] N.Tsukahara, presented at The 17thInternational Meeting on Lithium Batteries, Como, 2014 (unpublished) [2] T. Yamada, presented at The 56th Battery Symposium, Nagoya, 2015 (unpublished) Figure 1