scholarly journals XII.—On the Behaviour of the Hydrates and Carbonates of the Alkali-Metals, and of Barium, at High Temperatures, and on the Properties of Lithia and the Atomic Weight of Lithium

1890 ◽  
Vol 35 (2) ◽  
pp. 429-469
Author(s):  
W. Dittmar
Keyword(s):  
High Temperatures ◽  
Alkali Metals ◽  
Atmospheric Oxygen ◽  
Atomic Weight ◽  
Suitable Material ◽  
Corrosive Action ◽  
Chemical Inertness

The fragmentary nature of our knowledge of the behaviour of the more strongly basilous hydrates and carbonates at high temperatures is owing chiefly to the absence of a suitable material for the necessary crucibles. Unfortunately there is no metal which combines the infusibility of platinum with the chemical inertness of gold, in opposition to fiery-fluid caustic alkalies. But the corrosive action of these on platinum, as I showed some years ago, is a function only of the peroxides formed from them by the action of atmospheric oxygen, and, consequently, can easily be prevented by operating in an atmosphere of hydrogen or nitrogen.

scholarly journals The Thermal Stability of the Naphthalene Sulfonic Acids Under Geothermal Conditions

2021 ◽  
Author(s):  
◽  
Lucjan Sajkowski
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
High Temperatures ◽  
Solid Phase ◽  
Atmospheric Oxygen ◽  
Pure Water ◽  
Pressure Vessels ◽  
Geothermal Reservoirs ◽  
Flow Through ◽  
Thermal Stability Of

<p>A primary goal of this thesis was to obtain kinetic data on the breakdown and isomerisation reactions of naphthalene disulfonate (NDS) and naphthalene sulfonate (NSA) compounds under geothermal conditions. A secondary aim of this study was to investigate NDS/NSA isomerisation transformations as well as to study their kinetics and identify products of thermal disproportionation. Because of their apparent thermal stability, naphthalene disulfonate solutions have been frequently injected into active geothermal reservoirs and their subsequent detection (“recovery”) in nearby wells/bore holes used as an indicator of well connectivity and local permeability. The results obtained in this thesis will enable a more insightful interpretation of field injection results and fluid flow in active geothermal reservoirs. The studies presented in this thesis were designed to determine the thermal stability of aqueous NDS and NSA at high temperatures from 100 to 400°C in pure water and different salt solutions (i.e. NaCl +/- Na2SO4 and Na2S) at saturated vapour pressure. The stabilities and isomerisation transformations of NDS and NSA were also studied in the presence of solid materials (i.e. quartz, greywacke, pumice) which may occur in the host geological environment of hydrothermal/geothermal reservoirs in the Earth’s crust. Dilute aqueous solutions of NDS and NSA were contained in sealed silica glass ampoules (purged of atmospheric oxygen) and placed in stainless steel pressure vessels and heated for varying times to the desired high temperatures. Additional experiments were also conducted in which dilute NDS and NSA solutions were pumped from a de-oxygenated reservoir container through a flow-through autoclave containing different rock and mineral phases at temperatures up 400°C. The resulting NDS and NSA isomers were then analysed using HPLC and GC-MS methodologies. The 1,5-naphthalene disulfonate isomer (1,5-NDS) was found to be the least stable at pHt = 3 - 8 and readily transformed to 1-naphthalene sulfonate (1-NSA) at t ≥ 200°C. The 2-NSA was found to be the most stable isomer but disappeared at t ≥ 300°. The experimental data indicated that the stabilities of all the NDS and NSA studied as a function of temperature, pH and salt (NaCl) concentration were in the sequence: 1,5-NDS < 1,6-NDS < 2,6-NDS ≈ 2,7-NDS < 2-NSA. The presence of dissolved salts was shown to slow down the decomposition rates. Results from flow-through autoclave experiments suggest that between 100 and 250°C, the stabilities of 2,6-NDS, 2,7-NDS, 1,5-NDS and 1,6-NDS are mainly controlled by solution pH, while at t ≥ 300°C, temperature is the main stability controlling factor. Additionally, no adsorption of NDS/NSA on the surface of minerals was observed. A new high-performance liquid chromatography (HPLC) method combined with solid-phase extraction (SPE) was developed to enable detection of NDS/NSA breakdown products at t ≥ 300°C. In hydrothermal solutions at temperatures greater than 300°C, all the naphthalene sulfonate isomers become unstable with the formation naphthalene (NAP) and the two naphthol isomers, 1-naphthol (1-NAP) and 2-naphthol (2-NAP), as confirmed by both the new HPLC/SPE method and GC-MS (gas chromatography–mass spectroscopy). In addition, 1-chloronaphthalene was also detected (using GC-MS) as a high temperature reaction product NDS/NSA disproportionation in 0.05 m NaCl solutions. The results of the experiments carried out during this thesis indicate that the stabilities the naphthalene mono- and disulfonates are a function of temperature, pH and salt concentration. The naphthalene sulfonates transform to different isomers and the kinetics of these isomerisation reactions have been determined. At temperatures ≥ 300°C, the NDS and NSA compounds disproportionate to the naphthalene “backbone” molecule as well as to the two stable naphthols and 1-chloronaphthalene (in chloride containing solutions). The application of naphthalene sulfonates to determine well connectivity and local permeabilities in active geothermal reservoirs is thus rather more complicated than previously appreciated. An understanding of the various isomer transformations and their kinetics is required. Furthermore, naphthalene sulfonates injected into high temperature geothermal reservoirs are unstable and breakdown to naphthalene, naphthols and probable halogenated naphthalene compounds, none of which have been considered in the interpretation of NDS/NSA recovery data in active geothermal reservoirs. The thermal stabilities of NAP, 1- and 2-NAP and 1-chloronaphthalene indicate that these compounds may also be employed as connectivity tracers in high temperature (t ≥ 300°C) systems.</p>

Liquid-phase oxidation of tetralin with atmospheric oxygen at high temperatures

1968 ◽  
Vol 8 (1) ◽  
pp. 59-67
Author(s):  
I SARATOV ◽  
V SIMANOV ◽  
B GOLOVANENKO ◽  
S SARATOVA
Keyword(s):  
Liquid Phase ◽  
High Temperatures ◽  
Atmospheric Oxygen ◽  
Liquid Phase Oxidation ◽  
Phase Oxidation

BIOPOLYOLS AS ECOLOGICAL LUBRICANT

Tribologia ◽  
2016 ◽  
Vol 270 (6) ◽  
pp. 159-166 ◽  
Author(s):  
Marian W. SUŁEK ◽  
Zbigniew DĄBROWSKI ◽  
Marian SZCZEREK ◽  
Jolanta DRABIK
Keyword(s):  
High Temperatures ◽  
Vegetable Oils ◽  
Isopropyl Alcohol ◽  
Atmospheric Oxygen ◽  
Constant Load ◽  
Oxidizing Agent ◽  
New Approach ◽  
Constant Rate ◽  
Oil Derivatives ◽  
Lubricating Properties

Vegetable oils are characterized by high lubricity. Their applications are limited due to their low stability, particularly at high temperatures and in the presence of an oxidizing agent, e.g., atmospheric oxygen. A new approach has been proposed to obtain vegetable oil derivatives with higher stability. The approach consists in the epoxidation and then hydroxylation of the oils. These reactions resulted in obtaining a biopolyol in which double bonds were substituted by isopropyl alcohol. The biopolyol obtained was tested on a four-ball apparatus. The tests were carried out at a constant load, and the seizure tests were performed at a load increasing at a constant rate. The results obtained were compared with those for castor, sunflower, and rapeseed oils used in lubrication. It was found that biopolyol exhibited comparable or even better lubricating properties than the reference oils.

scholarly journals X. The thermal deformation of the crystallised normal sulphates of potassium, rubidium, and Cæsium

1899 ◽  
Vol 192 ◽  
pp. 455-498 ◽  
Keyword(s):  
Physical Properties ◽  
Thermal Deformation ◽  
Alkali Metals ◽  
Chemical Society ◽  
Atomic Weight ◽  
Large Size ◽  
Hygroscopic Nature ◽  
Similar Remark ◽  
The One ◽  
Double Sulphates

In a communication made to the Royal Society in April last (‘Phil. Trans.,’ A, vol. 191, 313) the author described an interference dilatometer, by the use of which, owing to the introduction of compensation for the expansion of the platinum-iridium interference apparatus by means of a disc of aluminium laid on the object, the delicate method of Fizeau is rendered equally sensitive in the determination of the expansion of solid substances, notably crystals, which cannot be obtained in blocks of the relatively large size hitherto required. The method is particularly applicable in the cases of those substances, including the crystals of most artificial chemical salts or other preparations, whose ground surfaces will not take a polish equal to that of glass. The author was led to devise it in order to be able to extend his investigations, concerning the relations between the morphological and physical properties of the crystals of isomorphous series of salts on the one hand and their chemical constitution on the other, to the thermal deformation of the salts in question. In previous communications to the Chemical Society the author has described the results of detailed observations of a large number of morphological and physical properties of the crystals of the series of normal alkali sulphates, containing as metal potassium, rubidium, and cæsium respectively (‘Journ. Chem. Soc.,' Trans., 1894, 628); of twenty-two double sulphates of the series R 2 M(SO 4 ) 2 , 6H 2 O in which R is represented by the same three alkali metals (‘Journ. Chem. Soc.,' Trans., 1893, 337 and 1896, 344); and of the normal selenates of these metals (‘Journ. Chem. Soc.,' Trans., 1897, 846). The general result of these investigations has been to show that the whole of the investigated morphological and physical properties of the crystals of these salts exhibit progressive variations which follow the order of pro­gression of the atomic weights of the three alkali metals (K = 39, Rb = 85·2, Cs = 132·7), so that the variations may be said to be functions of the atomic weight of the alkali metal, in the broad sense in which the term “function” is usually applied in connection with atomic weight. Of all the isomorphous series referred to, the normal sulphates alone prove to be suitable for an investigation of the thermal deformation. The double sulphates are unsuitable on account of the ease with which most of them lose water of crystallisa­tion when their temperature is raised, and a similar remark applies to the double selenates, whose investigation with respect to their morphological and physical properties is now proceeding. The simple selenates offer great difficulties on account of their excessively hygroscopic nature, which is so marked in the case of cæsium selenate, in accordance with the rapidly progressive advance in the solubility of the three salts which has been shown ( loc. cit . p. 851) to follow the order of the atomic weights of the metals, as to place it in the category of effective desiccating agents. The normal sulphate of potassium is absolutely free from this disadvantage, being one of the least soluble of the salts usually classed as soluble in water, 100 cub. centims. of this liquid at the ordinary temperature only dissolving 10 grams of the salt ( loc. cit. p . 851 and sulphate memoir loc. cit. p. 632). Rubidium sulphate is so slightly hygroscopic, its solubility being only 44 per cent., as to present no difficulty on this ground. Cæsium sulphate is decidedly hygroscopic, the solubility being so relatively great as 163 grams in 100 cub. centims. water. Although this characteristic is by no means so strong as in the analogous selenate, the solubility of cæsium selenate being no less than 245 grams in 100 cub. centims. water, still it is sufficiently marked to render the use of the salt for the purpose in question impossible in damp weather. The difficulty has, however, been successfully overcome in the case of cæsium sulphate, by taking advantage of the driest days of the recent remarkably dry summer, and of a few dry frosty ones of the early winter, together with the expedient of utilising the inner chamber of the air bath of the dilatometer as a desiccator, by placing a vessel containing oil of vitriol therein until the actual moment of commencing the obser­vations.

Thermodynamic properties of bcc crystals at high temperatures: The alkali metals

1984 ◽  
Vol 29 (12) ◽  
pp. 6489-6499 ◽  
Author(s):  
Rosemary A. MacDonald ◽  
Ramesh C. Shukla ◽  
David K. Kahaner
Keyword(s):  
Thermodynamic Properties ◽  
High Temperatures ◽  
Alkali Metals

scholarly journals Hyperfine structure and Zeeman-effect of the resonance lines of lithium

1939 ◽  
Vol 173 (953) ◽  
pp. 278-285 ◽  
Keyword(s):  
Hyperfine Structure ◽  
Hollow Cathode ◽  
Alkali Metals ◽  
Zeeman Effect ◽  
Atomic Weight ◽  
Doppler Width ◽  
Weak Line ◽  
Cathode Tube ◽  
Hyperfine Structures ◽  
Hollow Cathode Tube

Hyperfine structures have now been found and investigated in the resonance lines of all alkali metals except lithium. The low atomic weight of this element causes a relatively great Doppler width of the lines and very narrow hyperfine structures so that even with a cooled hollow-cathode tube the width of the lines is many times greater than the hyperfine structure. The structure of the resonance line 6708 A revealed by this light-source is due to the multiplet splitting and isotope shift (Schüler and Wurm 1927); it consists of two strong lines and one weak line, as shown in figure 1.

Trace element removal from hot gasification flue gases using solid sorbents

2013 ◽  
Vol 8 (2) ◽  
pp. 137-145
Keyword(s):  
Trace Elements ◽  
Gas Phase ◽  
High Temperatures ◽  
Alkali Metals ◽  
Coal Gasification ◽  
Fixed Bed ◽  
Fly Ashes ◽  
Metallic Oxide ◽  
Solid Sorbents ◽  
Element Removal

Coals contain elements which, although usually found in concentrations lower than 1% (trace elements), can give rise to environmental or technological problems. After gasification most of these elements may occur in gas phase in different proportions. In order to avoid the problems that the presence of trace elements in gas phase can originate during coal gasification processes, a suitable technology needs to be developed. The systems currently being studied and developed for gas cleaning in coal gasification, focus on the removal of sulphur, particulate matter, nitrogen, alkali metals and halogens but not on corrosive or toxic trace elements. Nevertheless, the reduction of trace elements using solid sorbents in gas phase at high temperatures appears to be a promising method for combustion systems. The main objectives of this work were to determine the capacity of different solid sorbents for retaining arsenic, selenium, cadmium and zinc species in gases from coal gasification systems at 550 and 750 ºC and to find out how the sorbent characteristics and operational variables (temperature and gas composition) influence retention. To attain these objectives the sorption capacity (mg of element per g of sorbent) and the efficiency (percentage of element retention) were determined. The study was carried out in a laboratory scale reactor, in which the sorbent was employed as a fixed bed, using synthetic gas mixtures. At the end of each experiment, the sorbent bed (mixture of sorbent + sand) was finely ground and dissolved in a microwave oven with HF, HNO3 and H3BO3, and the element in solution was determined by ICP-MS. The results are discussed in the light of the data for combustion conditions reported in the literature, and possible retention mechanisms are proposed. Different amounts of arsenic, selenium, cadmium, and zinc can be retained in solid sorbents at high temperatures. It was observed that, in a coal gasification atmosphere, limestone, fly ashes and metallic oxide mixtures containing spinels, were the best sorbents, though in each case the retention capacity depended on temperature and atmosphere. Retention capacities between 16-24 mg g-1 were obtained using limestone and fly ashes for arsenic retention. For selenium, the maximum retention capacities ranging between 50-56 mg g-1 were attained using limestone. Alumina in a gasification atmosphere containing HCl was the best sorbent for zinc removal (52 mg g-1). The lowest retention capacities were obtained for cadmium, these being <1 mg g-1 for the different sorbents tested. Retention probably proceeds through different mechanisms, but in most cases a chemical reaction is involved.

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