Carbonyl Sulfide Gas Research Articles

Design and Performance Assessment of a Mid-Wave Infrared InAsSb-based AlSb/InAlSb Barrier Photodetector for Carbonyl Sulfide Gas Detection as an Ultra-High Sensitivity Device in Industrial Applications

Design and Performance Assessment of a Mid-Wave Infrared InAsSb-based AlSb/InAlSb Barrier Photodetector for Carbonyl Sulfide Gas Detection as an Ultra-High Sensitivity Device in Industrial Applications

Carbonyl sulfide gas detection by pure, Zn- and Cd-decorated AlP nano-sheet

Carbonyl sulfide gas detection by pure, Zn- and Cd-decorated AlP nano-sheet

Adsorption of carbonyl sulfide on Pt-doped vacancy-defected SWCNT: A DFT study

Carbonyl sulfide (COS) is a dangerous gas produced from fossil fuel combustion and petrochemical procedures, so proper adsorbent and sensors are required for removal and detection. In this work, we study by Density Functional Theory methods the COS adsorption on a Pt-decorated vacancy-defected carbon nanotube, in order to evaluate the potential of this nanostructure as gas adsorbent or sensing material. First, we analyze the most stable configuration for Pt adsorption on the defective nanotube, obtaining a more favorable binding energy for a symmetric structure with equivalent CPt bonds. Next, several configurations are studied for COS adsorption on the Pt-doped nanotube. In the most stable systems, the adsorbate interacts with the Pt decoration through its C and S atoms, with adsorption energy values of about −2.7 eV. Overlap population and bonding order studies are also performed, showing a strong affinity between COS and the Pt-doped surface. Furthermore, an important electronic transfer from nanotube to the gas molecule was detected, which would indicate chemical adsorption. Density of states analysis also show a considerable stabilization of COS molecule after adsorption. Our study suggests that a Pt-doped carbon surface could act as a promising adsorbent and chemical sensor for COS gas removal or detection purposes.

Capturing ability for COS gas by a strong bridge bonding of a pair of potassium anchored on carbonate of activated carbon at low temperatures

To maximize the adsorption of COS (carbonyl sulfide) gas, activated carbon (AC) with a large surface area was modified with K as a low-cost adsorbent capable of bonding at low temperatures with the S in COS. The contents of AC and K were fixed at 80% and 20%, respectively. The COS gas was dynamically adsorbed by AC-K at an optimum temperature of 210 °C with a sulfur-adsorption capacity of 56.1 mg/g. The structure of the K adsorbent was confirmed as K2CO3 via X-ray diffraction and the K components were highly dispersed on the surface of the AC, as indicated by SEM and EDAX analyses. Furthermore, the correlation between the specific surface area of AC-K and COS adsorption was examined using FT-IR, XPS, and MASS analyses. The mechanisms by which the COS adsorbed/desorbed from the adsorbent were determined and an overall mechanism describing COS adsorption behavior was proposed.

Adsorption/desorption behavior of carbonyl sulfide gas on Scheelite type MWO4 adsorbent

Abstract This study focused the metal oxide adsorbents to remove small amounts of carbonyl sulfide (OCS) during coal gasification, which was a preliminary step for Integrated Gasification Fuel Cell operation. This study attempted to improve the function of the adsorbent by introducing two kinds of metal species, alkaline earth metals (M=Ca, Mg, Sr, and Ba) and W, fabricated as a Scheelite-typed MWO4 crystal. COS gases were broken down into CO and S segments on the surface of the adsorbents, and were then adsorbed onto the alkaline and W sides. The COS removals decreased in the order of CaWO4 > SrWO4 > BaWO4 > MgWO4 > WO3. When the adsorbent had an ideal basicity, the CO and S adsorbed well on the surface of the adsorbent, resulting in easy breakage of the CO and S bonds. But, this study indicated that it was more influential to optimally align the adsorbate and adsorbent surface. For the Scheelite-type CaWO4 adsorbent, the distance of the adsorbing active site, Ca O W, was similar in size to the COS adsorbate molecule, suggested a good alignment approaching the C-axis of the adsorbent. Moreover, an important result in this study determined by mass spectroscopy was that when COS adsorption was saturated on the MWO4 surface, the adsorbed COS gases could desorb from the MWO4 surface with CO2, SO2, CS, and CS2 gases, which are more toxic than COS. This can be considered to other secondary environmental pollutants.

Versatile silicon-waveguide supercontinuum for coherent mid-infrared spectroscopy

Laser frequency combs, with their unique combination of precisely defined spectral lines and broad bandwidth, are a powerful tool for basic and applied spectroscopy. Here, we report offset-free, mid-infrared frequency combs and dual-comb spectroscopy through supercontinuum generation in silicon-on-sapphire waveguides. We leverage robust fabrication and geometrical dispersion engineering of nanophotonic waveguides for multi-band, coherent frequency combs spanning 70 THz in the mid-infrared (2.5 μm–6.2 μm). Precise waveguide fabrication provides significant spectral broadening with engineered spectra targeted at specific mid-infrared bands. We characterize the relative-intensity-noise of different bands and show that the measured levels do not pose any limitation for spectroscopy applications. Additionally, we use the fabricated photonic devices to demonstrate dual-comb spectroscopy of a carbonyl sulfide gas sample at 5 μm. This work forms the technological basis for applications such as point sensors for fundamental spectroscopy, atmospheric chemistry, trace and hazardous gas detection, and biological microscopy.

Role of carbonyl sulfide in acute lung injury following limb ischemia/reperfusion in rats

ObjectiveTo investigate the effect of carbonyl sulfide (COS) on limb ischemia/reperfusion (I/R)-induced acute lung injury (ALI) and the associated mechanism in rats.MethodsALI was induced by bilateral hind limb I/R in Sprague–Dawley (SD) rats. Sixty-four SD rats were randomly divided into the control group, I/R group, I/R + COS group, and I/R + AIR group. We observed the survival rate of the rats and the morphological changes of lung tissues, and we measured the change in the lung coefficient, the expression levels of the intercellular adhesion factor-1 (ICAM-1) protein in lung tissue, the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-lβ, and interleukin (IL)-6 in both lung tissue and serum, and cell apoptosis.ResultsLimb I/R caused significant lung tissue damage. The number of polymorphonuclear neutrophil in alveolar septa, the expression level of the ICAM-1 protein in lung tissue, the expression levels of TNF-α, IL-1, and IL-6 in lung tissue and serum, the lung coefficient, and cell apoptosis all increased. When a low dose of COS gas was administered prior to limb I/R, the variation of the above indicators was significantly reduced, while an increase in the dose of COS did not reduce the lung injury but rather increased the mortality rate.ConclusionCarbonyl sulfide is another new gaseous signaling molecule, and a low dose of exogenous COS may play a protective role in I/R-induced ALI by acting as an anti-inflammatory agent by promoting the production of antioxidants and by inhibiting the expression of adhesion molecule proteins.

In situ soil COS exchange of a temperate mountain grassland under simulated drought

During recent years, carbonyl sulfide (COS), a trace gas with a similar diffusion pathway into leaves as carbon dioxide (CO2), but with no known “respiration-like” leaf source, has been discussed as a promising new approach for partitioning net ecosystem-scale CO2 fluxes into photosynthesis and respiration. The utility of COS for flux partitioning at the ecosystem scale critically depends on the understanding of non-leaf sources and sinks of COS. This study assessed the contribution of the soil to ecosystem-scale COS fluxes under simulated drought conditions at temperate grassland in the Central Alps. We used transparent steady-state flow-through chambers connected to a quantum cascade laser spectrometer to measure the COS and CO2 gas exchange between the soil surface and the atmosphere. Soils were a source of COS during the day, emissions being mainly driven by incoming solar radiation and to a lesser degree soil temperature. Soil water content had a negligible influence on soil COS exchange and thus the drought and control treatment were statistically not significantly different. Overall, daytime fluxes were large (12.5 ± 13.8 pmol m−2 s−1) in their magnitude and consistently positive compared to the previous studies, which predominantly used dark chambers. Nighttime measurements revealed soil COS fluxes around zero, as did measurements with darkened soil chambers during daytime reinforcing the importance of incoming solar radiation. Our results suggest that abiotic drivers play a key role in controlling in situ soil COS fluxes of the investigated grassland.

Probing the electronic sensitivity of BN and carbon nanotubes to carbonyl sulfide: A theoretical study

Density functional theory calculations were employed to investigate the electronic and structural behavior of a pristine boron nitride nanotube (BNNT) and a single-walled carbon nanotube (CNT) toward carbonyl sulfide (COS) gas adsorption. It was found that when a COS molecule is adsorbed on the CNT, an energy of about 6.0kcal/mol is released and the HOMO-LUMO gap of CNT is decreased by about 38.7%. Thus, the electrical conductivity of the CNT is significantly increased, indicating that the CNT can produce an electronic noise at the presence of COS molecules. The recovery time for the COS desorption from the surface of CNT is calculated to be very short (~0.24μs). Also, our finding and the literature review indicated that the CNT can selectively detect the COS gas among different ones including H2, H2CO, H2S, O2, etc. Compared to the CNT, the BNNT shows a higher reactivity toward the COS, but its electronic properties are insensitive to this gas. The adsorption energy of COS on the BNNT was calculated to be about 11.3kcal/mol.

The role of prop-1-ene-1,3-sultone as an additive in lithium-ion cells

Density functional theory (DFT) is used in conjunction with experimental results to propose decomposition pathways that describe the role and ultimate fate of the PES additive in Li-ion batteries. Oxidation of PES produces carbonyl sulfide gas and ethene at the positive electrode, both experimentally observed byproducts. However, the calculated standard potential for simple PES oxidation, E0ox ∼ 6.7 V vs. Li/Li+, is quite high, suggesting this pathway is unlikely. A “reactive electrode model” is presented, in which the positive electrode material is a reagent in the pseudo-combustion of PES (and other solvents). This spontaneous process produces carbonyl sulfide, carbon dioxide, and a rock salt surface layer, all of which are experimentally observed. At the negative electrode, the reduction of PES occurs via two one-electron steps, where E0red,1 = 0.9 V and E0red,2 = 4.3 V. The reduced species, Li2PES, can react with hydrogen and methyl radicals to produce propene, methylpropene, propane and lithium sulfite. Nucleophilic Li2PES can also react with electrophilic PES, ethylene carbonate, or ethyl methyl carbonate. Eighteen possible organic sulphate ‘building blocks’ for the solid-electrolyte interphase (SEI) are presented. X-ray photoelectron spectroscopy (XPS) measurements demonstrate that PES reduction indeed results in both lithium sulfite and organic sulphate SEI components.

Carbonate melt regeneration for efficient capture of SO2 from coal combustion

Sulfur emission in the form of SO2 in flue gas is the most serious pollutant associated with coal combustion. Calcium carbonate sulfur scrubbing, the process most commonly in use today, is costly, produces a large amount of waste and leaves a considerable amount of SO2 in the gas. The carbonate eutectic method for removing SO2 from flue gas at 450–650 °C was initially proposed in the 1970's but despite its great efficiency could not be used due to the complexity of the carbonate melt regeneration stage. We propose a simple way to remove sulfur from the carbonate eutectic melt by purging it with CO. In contrast to expectation, this reaction leads to the reduction of sulfate to carbonyl sulfide gas that leaves the melt, rather than to sulfide ions that remain in the melt. The experiments conducted show that nearly complete sulfur removal from the melt is possible at 550 °C and that the reaction rate is sufficiently high for a large scale process. The proposed modifications provide solutions to two critical issues: (i) at 550 °C there is no problem of corrosion because a reaction cell of stainless steel with high chromium content is stable with respect to the carbonate eutectic melt at that temperature and (ii) removal of sulfur in the form of COS, rather than H2S, provides considerable freedom in choosing the final product: either sulfuric acid or elemental sulfur. In addition, we verified that fly ash does not dissolve in the carbonate eutectic melt and therefore will not interfere with SO2 removal. One can foresee that the carbonate melt-based SO2 removal technique may become a practical and viable method for limiting sulfur emission to the atmosphere.

High precision measurements of atmospheric concentrations and plant exchange rates of carbonyl sulfide using mid‐IR quantum cascade laser

AbstractLinking measurements of carbonyl sulfide (COS) with those of carbon dioxide (CO2) has a potential in providing a powerful tracer of gross CO2 fluxes between the atmosphere and land plants, a critical element in understanding the response of the land biosphere to global change. A new application of online COS, CO2 and water vapor measurements based on newly designed mid‐infrared (IR) dual quantum cascade laser (QCL) spectrometer measures COS and CO2 (at 2056 cm−1) and water vapor (at 2190 cm−1), with detectors cooled thermoelectrically (at −43 °C) or with liquid nitrogen (−197 °C) for improved precision. Using the cryogenic detectors with averaging time of 1 s, precision was 50 pmol mol−1, 0.4 μmol mol−1 and 0.01 mmol mol−1 for COS, CO2 and water vapor, respectively (14, 0.2 and 0.003, respectively, for 60 s averaging time). We measured COS concentrations in ambient air, and changes in the rates of COS, CO2 and water vapor exchange of attached leaves in response to changes in light intensity and ambient COS concentrations. The results were consistent with those of nononline gas chromatography–mass spectrometry for COS and IR gas analyzer for CO2 and water vapor, with a high linear correlation for a broad range of concentrations (R2= 0.85 for COS and R2= 1.00 for CO2 and water vapor). The new methodology opens the way for lab and field explorations of COS fluxes as a powerful new tracer for CO2 exchange in the land biosphere.

Diode Laser Spectroscopy of the ν1and ν3Bands of SD+3

The ν1and ν3bands of SD+3were observed at 5.45 μm with a diode laser spectrometer. The ions were generated in a concentration-modulated, low-temperature, hollow-cathode discharge of deuterium and carbonyl sulfide gases. One hundred and ninety-two lines were measured and assigned to SD+3. The majority of these lines were assigned to the ν3perpendicular band with 49 lines assigned to the ν1parallel band. A simultaneous fit of these bands provided the first experimental parameters for the SD+3ion.

Sensitivity of Microwave Double Impedance Bridge for Fluid Analysis and Monitoring*

ABSTRACTA high sensitivity microwave double impedance bridge suitable for continuous analysis or monitoring of low loss fluid quality has been developed. Air and carbonyl sulfide gas were utilized as samples. A new microwave circuit component, “the air phase shifter” was introduced.