High Pressure H2S Research Articles

Tertiary-Amine-Functional Poly(arylene ether)s for Acid-Gas Separations.

Competitive sorption enables the emergent phenomenon of enhanced CO2-based selectivities for gas separation membranes when using microporous polymers with primary amines. However, strong secondary forces in these polymers through hydrogen bonding results in low solvent solubility, precluding standard solution processing approaches to form these polymers into membrane films. Herein, we circumvent these manufacturing constraints while maintaining competitive-sorption enhancements by synthesizing eight representative microporous poly(arylene ether)s (PAEs) with tertiary amines. High-pressure H2S, CO2, and CH4 sorption isotherms were collected for these samples to demonstrate enhanced affinity for acid gases relative to the unfunctional control polymer. Although competitive sorption was observed for all samples, improvements were less pronounced than for primary-amine-functional analogs. For H2S-based separations, the benefits of competitive sorption offset decreases in selectivity due to plasticization. This detailed study helps to elucidate the role of tertiary amines for acid gas separations in solution-processable microporous PAEs.

H2S adsorption on NaY zeolite

Abstract In this work, high-pressure H2S adsorption data in equilibrium and fixed bed conditions using NaY zeolite as adsorbent were determined. Adsorption and desorption isotherms for different temperatures and H2S partial pressures up to 1.2 bar were obtained experimentally and modelled with Toth and Dubinin-Astakhov equations in order to give information about adsorbate/adsorbent and adsorbate/adsorbate interactions. H2S adsorption in a fixed bed column was achieved for different inlet volumetric flow rates and breakthrough curve data were evaluated considering adsorbed amount, length of mass transfer zone, contributions of internal and external mass transfer resistances and were modelled with Linear Driving Force (LDF) model to estimate adsorbent particle's effective mass transfer coefficient. Equilibrium results indicate maximum uptake capacities are above 6.0 mol kg−1 for highest partial pressures. Isotherms' modeling suggests the predominance of physisorption of H2S in NaY zeolite. However, a hysteresis effect was observed for desorption curves and attributed to H2S chemisorption on zeolite surface, as pointed out by strongly favorable isotherms obtained. Fixed bed adsorption data showed breakthrough curves were nonsymmetrical, which indicated the presence of internal resistance mainly, probably due to the microporosity of adsorbent particle. In accordance, mass transfer zones did not vary significantly with inlet flow rate. Effective intraparticle mass transfer coefficients obtained with LDF model increases as flow rate increases, due to a higher availability of H2S molecules at adsorbent surface, which increases the driven force necessary for mass transfer in the intraparticle region.

Corrosion Resistance of Cu-Ni-Si Alloy Under High-Temperature, High-Pressure H2S and Cl− Environments

In this study, Cu-Ni-Si alloy was subjected to corrosion resistance tests under simulated high-temperature, high-pressure H2S and Cl− environments. The corrosion rates, electrochemical performance, surface morphologies, and chemical compositions of the Cu-Ni-Si alloy after corrosion were analyzed by the mass loss method, electrochemical impedance spectroscopy, scanning electron microscopy, energy-dispersive x-ray spectrometry, and x-ray diffraction. The results showed that, at the initial stage of corrosion, because of the loose corrosion product layer initially formed on the surface, a high corrosion rate was observed for the Cu-Ni-Si alloy under high-temperature, high-pressure environments. With the progress of corrosion, the corrosion rate gradually decreased and reached a steady state. Because at the later stage, a passive film was formed on the alloy surface, further inhibiting the corrosion of the alloy and improved its corrosion resistance. The Cu-Ni-Si alloy exhibited good corrosion resistance under high-temperature, high-pressure H2S and Cl− environments.

Influence of hydrogen sulfide annealing on copper–zinc–tin–sulfide solar cells sputtered from a quaternary compound target

With a theoretical efficiency around 30% and an optimized band gap for sunlight absorption, Cu2ZnSnS4 (CZTS) is a promising, earth-abundant, material for thin film solar cells. Sputtering CZTS from a quaternary compound target is a quick and potentially industrial-scaled process that has not been investigated deeply yet. Our approach is based on an in-line vacuum system for the complete device. CZTS is sputtered from a compound target on a sodium molybdate (MoNa) pre-sputtered stainless steel substrate, and then annealed in high-pressure H2S atmosphere. A 1 μm thick absorber is obtained within 7 minute sputtering. Top layers are then deposited, without vacuum breaking. The effects of different annealing temperatures on the absorber morphology and composition are investigated. It is observed that recrystallization already occurs at 420 °C and that crystallinity improves with increasing temperature up to 550 °C. However, micro-sphere formation underneath the film degrades the corresponding solar cell performance dramatically above 510 °C. It is shown that sodium is needed in order to enhance recrystallization of CZTS but the MoNa layer thickness seems not to be a critical parameter. Scanning electron microscopy, X-ray diffraction, X-ray fluorescence and current–voltage measurement were used to characterize the samples.

Investigation on the Property Degradation of Nickel-Base Alloy 825 in High Pressure H2S Environments

Investigation on the Property Degradation of Nickel-Base Alloy 825 in High Pressure H2S Environments

Estimation and measurements of pH in high temperature and high pressure sour environments.

A new technique for estimating the pH of concentrated aqueous solutions in equilibrium with high pressure H2S and CO2 at elevated temperature was proposed. Based on the thermodynamic investigation for solution properties, the following equation was obtained.pH=-logγH+{(K1, H, KH, H, PH2S/γ2±H2S)1/2+(K1, C, KH, C, PCO2/γ2±CO2)1/2}The physico-chemical parameters in the equation were calculated by PBILC (Principle of Balance of Identical-Like Charges) proposed by Cobble et al. or assumed to be identical with those for HCl+NaCl aqueous solutions. The calculation of the pH of high temperature and high pressure sour environments was facilitated by the of this equation.A Nb-doped TiO2 semiconductor electrode of n-type was found to be suitable for the measurement of the pH of the environments; no interference from NaCl, H2S and CO2 occurred. The measured pH values agreed well with those estimated by the newly proposed technique at the temperatures up to 473 K and at partial pressures of H2S and CO2 up to 4 MPa. It was ascertained by pH measurements for HCl+NaCl aqueous solutions at elevated temperatures that the assumption made for physico-chemical parameters in the pH estimation was valid.