Hydrothermal Reactions under Supercritical Conditions. IV. The Reaction between Strontium Hydroxide and Silica

1957 ◽  
Vol 61 (10) ◽  
pp. 1437-1439 ◽  
Author(s):  
J. F. Corwin ◽  
R. G. Yalman ◽  
J. W. Edwards ◽  
E. R. Shaw
Keyword(s):  
Supercritical Conditions ◽  
Hydrothermal Reactions ◽  
Strontium Hydroxide

Hydrothermal reactions in lime-quartz pastes

1960 ◽  
Vol 10 (1) ◽  
pp. 7-15
Author(s):  
A. Aitken ◽  
H. F. W. Taylor
Keyword(s):  
Hydrothermal Reactions

Energy-saving technologies of technical service and processing of organic waste

2020 ◽  
pp. 65-75
Author(s):  
Anatoliy V. Fedotov
Keyword(s):  
Wastewater Treatment ◽  
Diesel Engine ◽  
Energy Saving ◽  
Organic Waste ◽  
Research Purpose ◽  
Industrial Complex ◽  
Technical Service ◽  
Supercritical Conditions ◽  
Drilling Rig ◽  
Aluminum Oxyhydroxide

Agricultural production in the Russian Federation is several times more energy-and material-intensive than in developed countries. (Research purpose) The research purpose is evaluation of the effectiveness of energy-saving technologies for technical maintenance of equipment using nanostructured aluminum oxyhydroxide and hydrothermal processing of agricultural waste in supercritical conditions. (Materials and methods) Nanostructured aluminum oxyhydroxide (boehmite) was produced by hydrothermal synthesis from aluminum powders. Tribological studies were carried out on a four-ball friction machine, a special device from WAGNER, on friction machines 2070 SMT-1M and MTU. Bench-in run was carried out on the D-240 engine and gearbox of a mobile drilling rig. The crushed solid waste of the agro-industrial complex was used as adsorbents for organic wastewater pollution. Their joint processing was carried out under hydrothermal supercritical conditions. (Results and discussion) It has been shown that nanostructure boehmite has antifriction, antiwear and extreme pressure properties. The possibility of its use as a product for running of a diesel engine has been found. The application of the boehmite in oils accelerates the running-in of a diesel engine, provides savings in material, labor and energy resources. For running-in of power transmission units, an additive containing bemite, surfactant, talc and kaolin reduced the running-in time of the drilling rig gearbox by 2.5 times. The article shows that the crushed plant waste of the agro-industrial complex, such as buckwheat husk, rice, and sunflower can be effectively used as adsorbents for the localization of pollution and wastewater treatment of agricultural enterprises. Subsequent processing of the adsorbent saturated with organic matter under hydrothermal supercritical conditions ensures the complete processing of organic substances to produce purified water and a high-enthalpy vapor-gas mixture or combustible gases, depending on the processing conditions. (Conclusions) Energy-saving technologies for the technical service of a diesel engine and transmission units can be based on the use of tribotechnical materials containing nanostructure boehmite. Technological solutions for energy-saving technologies for processing solid and liquid organic waste can consist in adsorption wastewater treatment followed by hydrothermal treatment in supercritical conditions.

scholarly journals Morphology Controlled Synthesis of γ-Al2O3 Nano-Crystallites in Al@Al2O3 Core–Shell Micro-Architectures by Interfacial Hydrothermal Reactions of Al Metal Substrates

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 310
Author(s):  
Dohyeon Han ◽  
Doohwan Lee
Keyword(s):  
Electrostatic Interactions ◽  
Heterogeneous Catalysts ◽  
Metal Substrate ◽  
Inorganic Anions ◽  
Core Shell ◽  
Hydroxyl Groups ◽  
Hydrothermal Reactions ◽  
Fine Control ◽  
Reaction Processes

Fine control of morphology and exposed crystal facets of porous γ-Al2O3 is of significant importance in many application areas such as functional nanomaterials and heterogeneous catalysts. Herein, a morphology controlled in situ synthesis of Al@Al2O3 core–shell architecture consisting of an Al metal core and a porous γ-Al2O3 shell is explored based on interfacial hydrothermal reactions of an Al metal substrate in aqueous solutions of inorganic anions. It was found that the morphology and structure of boehmite (γ-AlOOH) nano-crystallites grown at the Al-metal/solution interface exhibit significant dependence on temperature, type of inorganic anions (Cl−, NO3−, and SO42−), and acid–base environment of the synthesis solution. Different extents of the electrostatic interactions between the protonated hydroxyl groups on (010) and (001) facets of γ-AlOOH and the inorganic anions (Cl−, NO3−, SO42−) appear to result in the preferential growth of γ-AlOOH toward specific crystallographic directions due to the selective capping of the facets by adsorption of the anions. It is hypothesized that the unique Al@Al2O3 core–shell architecture with controlled morphology and exposed crystal-facets of the γ-Al2O3 shell can provide significant intrinsic catalytic properties with enhanced heat and mass transport to heterogeneous catalysts for applications in many thermochemical reaction processes. The direct fabrication of γ-Al2O3 nano-crystallites from Al metal substrate with in-situ modulation of their morphologies and structures into 1D, 2D, and 3D nano-architectures explored in this work is unique and can offer significant opportunities over the conventional methods.

Sign in / Sign up

Export Citation Format

Share Document