scholarly journals THE USE OF ULTRASOUND IN THE PREPARATION OF THE CATALYST Ru/HPS MN 100 AND ITS ACTIVITY IN THE PROCESS OF HYDROGENATION OF XYLOSE AND LACTOSE

2021 ◽  
pp. 41-48
Author(s):  
Максим Евгеньевич Григорьев ◽  
Роман Викторович Бровко ◽  
Евгений Олегович Долуда
Keyword(s):  
Aqueous Solution ◽  
Partial Pressure ◽  
Catalytic System ◽  
Ultrasonic Treatment ◽  
Ruthenium Catalyst ◽  
Hydrogenation Process ◽  
Continuous Reactor ◽  
Optimal Conditions ◽  
Type Reactor ◽  
Kinetic Testing

В работе рассмотрена возможность использование ультразвука при получении рутений содержащей каталитической системы Ru/СПС MN 100. Проведено кинетическое тестирование данного катализатора и сравнение его активности с таким же катализатором, но синтезированным без использования ультразвука, в процессе гидрирования ксилозы и лактозы до соответствующих полиолов - ксилита и лактита. Процесс гидрирования осуществлялся в реакторе периодического и непрерывного действия при оптимальных условиях (температуре, концентрации моно- и дисахарида, парциальном давлении водорода, скорости подачи водного раствора ксилозы и лактозы и скорости подачи водорода). Установлено, что ультразвуковая обработка рутениевого катализатора способствует повышению его активности, что отражается на увеличении конверсии моно- и дисахарида при проведении процесса в периодических условиях, при этом практически не происходит изменения конверсии субстратов при их гидрировании в реакторе проточного типа. The paper considers the possibility of using ultrasound in the production of ruthenium-containing catalytic system Ru/SPS MN 100. Kinetic testing of this catalyst was carried out and its activity was compared with the same catalyst, but synthesized without the use of ultrasound, in the process of hydrogenation of xylose and lactose to the corresponding polyols - xylitol and lactite. The hydrogenation process was carried out in a periodic and continuous reactor under optimal conditions (temperature, concentration of mono - and disaccharide, partial pressure of hydrogen, the rate of supply of an aqueous solution of xylitol and lactite and the rate of supply of hydrogen). It was found that ultrasonic treatment of the ruthenium catalyst contributes to an increase in its activity, which is reflected in an increase in the conversion of mono - and disaccharide during the process under periodic conditions, while there is practically no change in the conversion of substrates during their hydrogenation in a flow-type reactor.

An iron–nitrogen doped carbon and CdS hybrid catalytic system for efficient CO2 photochemical reduction

2021 ◽  
Vol 57 (16) ◽  
pp. 2033-2036
Author(s):  
Jin-Han Guo ◽  
Xiao-Yao Dao ◽  
Wei-Yin Sun
Keyword(s):  
Aqueous Solution ◽  
Catalytic System ◽  
Hybrid System ◽  
Photochemical Reduction ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

A new iron–nitrogen doped carbon and CdS hybrid system was developed to efficiently reduce CO2 to CO under UV/vis light (AM 1.5G) irradiation in aqueous solution.

scholarly journals Removal of Pb, Cu, Cd, and Zn Present in Aqueous Solution Using Coupled Electrocoagulation-Phytoremediation Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Francisco Ferniza-García ◽  
Araceli Amaya-Chávez ◽  
Gabriela Roa-Morales ◽  
Carlos E. Barrera-Díaz
Keyword(s):  
Aqueous Solution ◽  
Current Density ◽  
Batch Reactor ◽  
Operating Time ◽  
Typha Latifolia ◽  
Optimal Conditions ◽  
Lead And Zinc ◽  
Parallel Arrangement ◽  
Aluminum Electrodes ◽  
Cadmium Lead

This study presents the results of a coupled electrocoagulation-phytoremediation treatment for the reduction of copper, cadmium, lead, and zinc, present in aqueous solution. The electrocoagulation was carried out in a batch reactor using aluminum electrodes in parallel arrangement; the optimal conditions were current density of 8 mA/cm2 and operating time of 180 minutes. For phytoremediation the macrophytes, Typha latifolia L., were used during seven days of treatment. The results indicated that the coupled treatment reduced metal concentrations by 99.2% Cu, 81.3% Cd, and 99.4% Pb, while Zn increased due to the natural concentrations of the plant used.

Dissolution of spent nuclear fuel fragments at high alkaline conditions under H2 overpressure

MRS Advances ◽  
2016 ◽  
Vol 1 (62) ◽  
pp. 4163-4168
Author(s):  
E. González-Robles ◽  
M. Herm ◽  
V. Montoya ◽  
N. Müller ◽  
B. Kienzler ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Partial Pressure ◽  
Nuclear Fuel ◽  
Alkaline Solution ◽  
Spent Nuclear Fuel ◽  
Dissolution Tests ◽  
The Matrix ◽  
Alkaline Conditions ◽  
Long Term Behavior

ABSTRACTThe long-term behavior of the UO2 fuel matrix under conditions of the Belgian “Supercontainer design” was investigated by dissolution tests of high burn-up spent nuclear fuel (SNF) in high alkaline solution under 40 bar of (Ar + 8%H2) atmosphere. Four fragments of SNF, obtained from a pellet previously leached during two years, were exposed to young cement water with Ca (YCWCa) under 3.2 bar H2 partial pressure in four single/independent autoclave experiments for a period of 59, 182, 252 and 341 days, respectively. After a decrease of the concentration of dissolved 238U, which is associated with a reduction of U(VI) to U(IV), the concentration of 238U in solution is constant in the experiments running for 252 and 341 days. These observations indicate an inhibition of the matrix dissolution due to the presence of H2. A slight increase in the concentration of 90Sr and 137Cs in the aqueous solution indicates that there is still dissolution of the grain boundaries. These findings are similar to those reported for spent nuclear fuel corrosion in synthetic near neutral pH solutions.

Measurement of Complex Dielectric Permittivity of Quartz Systems

2019 ◽  
Vol 946 ◽  
pp. 129-133
Author(s):  
Vitaly Smolko ◽  
Elizaveta Antoshkina
Keyword(s):  
Aqueous Solution ◽  
Dielectric Permittivity ◽  
Polyvinyl Alcohol ◽  
Specific Surface ◽  
Ultrasonic Treatment ◽  
Complex Dielectric Permittivity ◽  
Active Centers ◽  
Sand Surface ◽  
Quartz Sands

The article describes the problem of the experimental determination of complex dielectric permittivity for natural, activated, and modified quartz systems. The results of determination of specific surface, complex dielectric permittivity, sands porosity are presented in this article. The authors obtained the empirical equation of complex dielectric permittivity calculation for natural, activated, and modified quartz sands, taking into account the effect of moisture, specific surface, porosity, impurities content into consideration. The modification of the sand surface by means of mechanical beneficiation and ultrasonic treatment leads to reduction of complex dielectric permittivity and specific surface, thus contributing to the increase of the active centers quantity on the sands surface. The modification of the sand surface by polyvinyl alcohol aqueous solution leads to increase of complex dielectric permittivity. Polyvinyl alcohol aqueous solution modification envisages the creation of new active centers by oligomers inoculation to the surface and blocking the clay component and authigenous film ingredients. Among the considered methods, ultrasonic treatment in aqueous solution and mechanical beneficiation are the most efficient and technologically acceptable ways of activation.

scholarly journals Preparation of 1-Hydroxy-2,5-hexanedione from HMF by the Combination of Commercial Pd/C and Acetic Acid

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2475 ◽  
Author(s):  
Yanliang Yang ◽  
Dexi Yang ◽  
Chi Zhang ◽  
Min Zheng ◽  
Ying Duan
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Reaction Time ◽  
Catalytic System ◽  
Biomass Conversion ◽  
High Concentration ◽  
Influence Of Temperature ◽  
Catalyst Amount

The development of a simple and durable catalytic system for the production of chemicals from a high concentration of a substrate is important for biomass conversion. In this manuscript, 5-hydroxymethylfurfural (HMF) was converted to 1-hydroxy-2,5-hexanedione (HHD) using the combination of commercial Pd/C and acetic acid (AcOH) in water. The influence of temperature, H2 pressure, reaction time, catalyst amount and the concentration of AcOH and HMF on this transformation was investigated. A 68% yield of HHD was able to be obtained from HMF at a 13.6 wt% aqueous solution with a 98% conversion of HMF. The resinification of intermediates on the catalyst was characterized to be the main reason for the deactivation of Pd/C. The reusability of the used Pd/C was studied to find that most of the activity could be recovered by being washed in hot tetrahydrofuran.

Enhancement of saccharin removal from aqueous solution by activated carbon adsorption with ultrasonic treatment

2006 ◽  
Vol 13 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Eileen C. Bernardo ◽  
Tadashi Fukuta ◽  
Takafumi Fujita ◽  
Erwin P. Ona ◽  
Yoshihiro Kojima ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Ultrasonic Treatment ◽  
Activated Carbon Adsorption ◽  
Carbon Adsorption

scholarly journals Sustainable Dyeing of Cellulosic Fabric with Reactive Violet H3R dye: Ultrasonic Assisted Improvement in Color Characteristic

2021 ◽  
Vol 65 (3) ◽  
Author(s):  
Shahid Adeel ◽  
Shumaila Kiran ◽  
Maria Jannat ◽  
Nimra Amin ◽  
Atya Hassan ◽  
...  
Keyword(s):  
Cotton Fabric ◽  
Ultrasonic Treatment ◽  
Green Technology ◽  
Optimal Conditions ◽  
Reactive Dyeing ◽  
Color Features ◽  
Colour Strength ◽  
Ultrasonic Assisted ◽  
Cellulosic Fabric ◽  
Glauber Salt

Abstract. Ultrasonic radiation (U. S.) is the sustainable and green technology which has transformed the domain of textiles. In the current study, ultrasonic treatment was employed to improve the reactive dyeing of cellulosic fabricby Violet H3R dye. For this purpose, U.S. treatment has been given to both solution & fabric upto 50 min. at 30 to 60 oC. Promising results were obtained when cellulosic fabric was exposed to U.S. treatment at at 50 oC for a period of 30 min. using dye bath of 55 mL having 7.5 pH. Glauber salt (8 g/L) was employed as an exhausting agent at 60 oC for 55 min. Various shades of cotton fabric dyed at optimal conditions were obtained which showed that U.S. treatment has enhanced not only the colour strength but also  the fastness rating from medium to outstanding. So, it can be concluded from the current study that U. S. treatment is not only good enough for improving the dyeing aptitude of Reactive Violet H3R dye but it also uplifts the color features of dyed cotton fabric.   Resumen. La radiación ultrasónica (U:S. por sus siglas en inglés) es la tecnología sostenible y verde que ha transformado el campo de los textiles. En este estudio, se llevó a cabo un tratamiento ultrasónico para mejorar el teñido reactivo de tela celulósica por el tinte Violet H3R. Para este propósito, se llevó a cabo un tratamiento con ultrasonido tanto a la solución como a la tela por hasta 60 minutos a 30 y 60 oC. Se obtuvieron resultados prometedores cuando la tela celulósica se expuso a un tratamiento con ultrasonido a 50 oC durante un período de 30 min, utilizando un baño de tinte (de 55 mL) a pH 7,5 de sal de Glauber (8 g/L). Estas condiciones representan un sistema de agotamiento, aplicado a 60 oC durante 55 min. Se obtuvieron varios tonos de tela de algodón teñidos en condiciones óptimas, lo que mostró que el tratamiento por ultrasonido mejora no solo la intensidad del color sino también el índice de solidez de media a sobresaliente. Por lo tanto, del estudio actual se puede concluir que el tratamiento con ultrasonido no solo es lo suficientemente bueno para mejorar la capacidad de teñido del tinte Reactive Violet H3R, sino que también realza las características del color de la tela de algodón teñida.

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