The Experts below are selected from a list of 1362 Experts worldwide ranked by ideXlab platform
Denise Maria Malachini Miotto - One of the best experts on this subject based on the ideXlab platform.
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synthesis of na a and x zeolites from Oil Shale ash
Fuel, 2005Co-Authors: Nadia Regina Camargo Fernandes Machado, Denise Maria Malachini MiottoAbstract:Abstract The solid by-product of Oil Shale Processing (PETROBRAS–Brazil) was used as a raw material to synthesize Na–A and –X zeolites. Two preparation methods using the same starting material composition were carried out. In Method (1), alkaline fusion was used to prepare a glass, which was then hydrated by refluxing. The largest amount of crystallinity was reached with 2 h 30 min of refluxing. In Method (2), alkaline fusion was followed by hydrothermal treatment. The most crystalline sample was obtained after 12 h of heat treatment, and after 96 h hydroxysodalite zeolite was formed. In both procedures, the synthesis products were mainly composed of Na–X zeolite, whose content was influenced by the crystallization time, and of Na–A zeolite, with a practically constant content.
G A Ryabov - One of the best experts on this subject based on the ideXlab platform.
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development of measures to improve technologies of energy recovery from gaseous wastes of Oil Shale Processing
Thermal Engineering, 2016Co-Authors: A N Tugov, A Ots, A Siirde, V T Sidorkin, G A RyabovAbstract:Prospects of the use of Oil Shale are associated with its thermal Processing for the production of liquid fuel, Shale Oil. Gaseous by-products, such as low-calorie generator gas with a calorific value up to 4.3MJ/m3 or semicoke gas with a calorific value up to 56.57 MJ/m3, are generated depending on the Oil Shale Processing method. The main methods of energy recovery from these gases are either their cofiring with Oil Shale in power bOilers or firing only under gaseous conditions in reconstructed or specially designed for this fuel bOilers. The possible use of gaseous products of Oil Shale Processing in gas-turbine or gas-piston units is also considered. Experiments on the cofiring of Oil Shale gas and its gaseous Processing products have been carried out on bOilers BKZ-75-39FSl in Kohtla-Jarve and on the bOiler TP-101 of the Estonian power plant. The test results have shown that, in the case of cofiring, the concentration of sulfur oxides in exhaust gases does not exceed the level of existing values in the case of Oil Shale firing. The low-temperature corrosion rate does not change as compared to the firing of only Oil Shale, and, therefore, operation conditions of bOiler back-end surfaces do not worsen. When implementing measures to reduce the generation of NO x , especially of flue gas recirculation, it has been possible to reduce the emissions of nitrogen oxides in the whole bOiler. The operation experience of the reconstructed bOilers BKZ-75-39FSl after their transfer to the firing of only gaseous products of Oil Shale Processing is summarized. Concentrations of nitrogen and sulfur oxides in the combustion products of semicoke and generator gases are measured. Technical solutions that made it possible to minimize the damage to air heater pipes associated with the low-temperature sulfur corrosion are proposed and implemented. The technological measures for burners of new bOilers that made it possible to burn gaseous products of Oil Shale Processing with low emissions of nitrogen oxides are developed.
Kalle Kirsimae - One of the best experts on this subject based on the ideXlab platform.
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long term mineral transformation of ca rich Oil Shale ash waste
Science of The Total Environment, 2019Co-Authors: Kristjan Leben, Riho Motlep, Peeter Paaver, Alar Konist, T Pihu, Paarn Paiste, Ivo Heinmaa, Gunnar Nurk, Edward J Anthony, Kalle KirsimaeAbstract:Abstract Power generation and other industries using solid fossil fuels like coal, lignite, Oil Shale and peat are responsible for producing large quantities of solid residues that are often chemically reactive and/or unstable and are disposed in holding ponds and deposition sites. Stability and long-term behaviour of such deposits are typically studied in short-term laboratory experiments that cannot describe nor predict long-term changes taking place in these materials. Here, we study long-term (>40 years) transformations, in highly alkaline conditions, of the Ca-rich ash deposit in Estonia composed of Oil Shale Processing residues from the Eesti power plant. Detailed mineralogical, chemical and micromorphological analyses using X-ray diffraction, X-ray fluorescence, 29Si nuclear magnetic resonance, scanning electron microscopy and other methods were applied in order to identify the composition of the waste with a focus on formation and transformation of semicrystalline phases in the deposit. The results show progressive formation of calcium-silicate-hydrate (C-S-H) type phase at the expense of silicate minerals and amorphous glass phases with increasing depth and age of the sediments, from about 25% in the upper part of the depository to over 60% in the oldest-deepest part. This demonstrates that over time the high alkalinity of the ash is responsible for initiating natural alkali-activation. The formation of C-S-H-type phases increases the mechanical strength of the sediment and ensures long-term stability of waste deposits. These findings may encourage the use of these ashes in binder or other construction material production or as construction aggregates.
Abdelaziz Khlaifat - One of the best experts on this subject based on the ideXlab platform.
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conversion of Oil Shale ash into zeolite for cadmium and lead removal from wastewater
Fuel, 2004Co-Authors: Reyad Shawabkeh, Adnan Alharahsheh, Malik Hami, Abdelaziz KhlaifatAbstract:A by-product fly ash from Oil Shale Processing was converted into zeolite by alkali hydrothermal activation using sodium hydroxide. The activation was performed at different activation temperatures using 8 M sodium hydroxide. The obtained cation exchange capacity (CEC) showed that the best condition for synthesis of zeolite performed in a closed reactor at 160 8C for 24 h. Powder patterns of X-ray diffraction analysis have shown that zeolite of type Na-PI was successfully synthesized at 29.5, 32.2 and 34.48. The produced zeolite was used as an ion exchanger for the treatment of wastewater for metal ions. Lead and cadmium were chosen as target metal ions. The adsorption capacity was estimated to be 70.58 mg lead/g-zeolite and 95.6 mg cadmium/g-zeolite when the initial concentration for both ions was 100 mg/l. The results were correlated using Redlich‐ Peterson and Sips models. For cadmium the best fit was obtained with the Sips model while, for lead the Sips models fits the experimental data adequately. Based on such results, it is concluded that the treated ash may possess strong potentials for zeolite production used in wastewater treatment. q 2003 Elsevier Ltd. All rights reserved.
A A Vostrikov - One of the best experts on this subject based on the ideXlab platform.
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non isothermal conversion of the kashpir sulfur rich Oil Shale in a supercritical water flow
Journal of Supercritical Fluids, 2016Co-Authors: O N Fedyaeva, Vladimir R Antipenko, Dmitriy Yu Dubov, Tatyana V Kruglyakova, A A VostrikovAbstract:Abstract The conversion of the Kashpir Oil Shale (gross-formula CH1.48N0.01S0.10O0.24) in a flow of water vapor and supercritical water at uniform increase in temperature (dT/dt = 1 °C/min) from 300 to 550 °C has been studied. Temperature dependences of the yields of the volatile and liquid products and their component and elemental compositions have been determined. The total yields of the volatile and liquid products and the conversion residue formed during the experiment have been found to be equal to 404.8, 383.8, and 543.0 mg/gC, respectively. The maximum yield of the volatile products, containing H2S, CO2, H2, and CH4 as major components, is observed at 300–360 °C. A high yield of these compounds is brought about by the redox reactions of Oil Shale organic matter and mineral components with water. The maximum yield of the liquid products is observed at 360–390 °C, the Oil fraction in their composition increasing from 57% to 78% along with increase in temperature. The composition of the liquid products is defined by means of IR and 1H NMR spectroscopy. A new approach to the problem of the Kashpir Oil Shale Processing in SCW in order to obtain the desired S-containing products is discussed.
