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Showing 1 to 20 of 40 for “"Strong acid"”.
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Zeolite deactivation during hydrocarbon reactions: characterisation of coke precursors and acidity, product distribution
… This deactivation is due to the poisoning of the acid sites and/or pore blockage. The formation of coke on hydrocarbon processing catalysts is of considerable technological and economic importance and a great deal of work has been carried out to this study. The main aim of this work is to …
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The equilibria and kinetics of certain ion exchange systems
… Ca⁺² equilibria and kinetics of both a gel type strong acid cation resin (Cation Fort) and a macroporous strong acid cation resin (Zerolit 625) were investigated and compared, as well as the Cl⁻, SO₄²⁻ and artificial COD kinetics of a macroporous normal density weak base, anion resin (Zerolit …
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Catalytic C-N and C-F bond formation by organometallic group 11 complexes
… Treatment of (fluorovinyl)gold(I) complexes with strong acid protonates the vinylic group with strong acid to afford trans-hydrofluorination. The same fluoroalkene product is obtained by treatment of an (1i2-alkyne)gold(I) complex with the mild HF source Et3N.3HF. Cationic (NHC)gold(I) complexes …
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Heats of Neutralization of Sodium and Potassium Hydroxides with Sulfuric and Hydrochloric Acids Measured in an Ice Calorimeter
The heat evolved when a strong acid and a strong base react together in dilute solution affords a test in favor of Hess’s theory of ionization. In the case of the interaction of HC1 with KOH, or NaOH, in solution there is a remarkably close agreement among the values of deltaH. The average value is …
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Treatment of plating plant wash waters by ion exchange
… investigated. The loading characteristics of a strong acid resin has been studied experimentally and by mathematical simulation. The ability to separate the loaded metals by complexation techniques during elution has been demonstrated. Good agreement between predicted and actual elution …
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The impact of plantations of Pinus spp. on the chemical properties of soils and stream waters in South African upland catchments
… constitute a significant component of the acid load to forest soils and can result in significant decreases in soil pH, acid neutralising capacity and base status. Despite this, the possibility that these processes can result in a significant transfer of acidity to drainage solutions and …
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The isolation and characterization of a growth factor in rumen fluid for a strain of Butyrivibrio
… resins. It can be eluted from the resins with strong acid. It is stable to enzymatic hydrolysis by trypsin. Granular mucin or bovine saliva will partially replace the stimulatory activity. The part of the material which was not replaced by mucin did not appear to be any compound that is …
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Polymer-supported reagents for disinfection of water
… via sulfonyl chloride by modification of the strong acid cation exchange resin, Amberlyst-15. The products obtained after treatment contained -SO2NH2 and -SO 3H groups. The sulfonic acid groups were determined by a total ion exchange capacity measurement. The sulfonamide groups were …
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Synthesis and Characterization of Anhydrous Proton Conducting Polymer Electrolytes for Fuel Cell Applications
… for better performance of the fuel cell. Acid dissociation constant studies of MePEGnSO3H acids observed strong acid behavior of acids in the aqueous medium and they incompletely dissociate in the MePEGn polymers.
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Characterization of acidic and basic properties of heterogeneous catalysts by test reactions
… done by catalytic test reactions. In contrast to acid catalysed test reactions which are actually well understood there is a need to study base catalysed reactions in detail. Therefore reactions in gas phase like conversion of methyl butynol (MBOH) and isopropanol and in liquid phase like …
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Development of nitroguanidine wastewater treatment technologies
… capacity was found to be 0.045 g NQ/g carbon. Strong acid resin was found to reduce guanidinium ion Gu⁺ concentration from 14.5 mg/L to 1 mg/L with a resin capacity of 0.13 eq Gu⁺ /L resin. No significant reduction in resin capacity for Gu⁺ was experienced after five regenerant cycles. A unique …
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Evaluating the Leachability of Elements from Residuals Generated by Hydraulic Fracturing in Marcellus Shale
… for the elements to leach from the landfill. Strong acid digestion using a 3:1 combination of nitric acid to hydrochloric acid in a microwave with closed vessels was used to determine overall elemental composition. Leaching experiments were performed with de-ionized water and acetic acid …
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The deactivation of Zeolite-Y and mordenite during hexane cracking and propene oligomerisation
… because of their different pore structures and acid site distributions. Hexane cracking at 1 atmosphere and high pressure propene oligomerisation provided two different reaction types. The transport properties of the catalysts were compared by measuring adsorption and diffusion using the GC …
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Estudo do mecanismo de corrosão pelo CO2 em aço carbono via técnicas eletroquímicas em condições que incluem alta pressão e temperatura
… steel if compared to the medium containing strong acid with the same pH and this scenario makes even more relevant the development and improvement of corrosion models used to predict corrosion rate of steels. In this context, the role of CO2 in the anodic dissolution mechanism of carbon …
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Alkylation of phenol with methanol over H-ZSM-5, H-Beta, H-Mordenite, H-USY and H-MCM-22
… can be obtained over aluminium oxides with strong acid sites, silica alumina, zeolites, aluminium phosphates and phosphoric acid-Kieselguhr catalysts. However, direct synthesis of high purity m-cresol and p-cresol is desirable due to the high costs of separating these two isomers. Thus to …
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Evaluating Leachability of Residual Solids from Hydraulic Fracturing in the Marcellus Shale
… and leaching potential for elements of concern. Strong acid digestions were performed to determine the total environmentally available composition, whereas weak acid digestions were used to predict the leaching potential of these solids under various environmental conditions. The extraction …
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Methanol conversion to olefins and propene oligomerization over modified SAPO-34 and dealuminated mordenite
… : (i) Silanization - in order to neutralize the acidity on the external surface of the crystallites and hence reduce pore-mouth blockage by coke species on the crystallite external surface; (ii) Steaming - to investigate the effect of more severe hydrothermal conditions than those encountered …
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A Study of the Three Component System Sulfamic Acid - Magnesium Sulfamate - Water at 26°C
… a much simpler experiment. Water - Sulfamic acid - Magnesium sulfamate is such a system. Sulfamic acid has just recently been placed on the market. Like sulfuric acid, it is highly ionized in aqueous solution, so it is similarly a strong acid. The fact that it ionizes in solution has been …
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Caesium and strontium exchange at specific clay mineral sites
… interlayer region is resistant to desorption and strong acid attack.
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