Microwave Heating of Hydrated Zeolites and Application of Zeolites as a Domestic Reusable Desiccant through its Technique

2005 ◽  
Vol 23 ◽  
pp. 195-198
Author(s):  
Tatsuo Ohgushi ◽  
Mayumi Nagae
Keyword(s):  
Adsorption Capacity ◽  
Microwave Heating ◽  
Microwave Radiation ◽  
Heating Temperature ◽  
Microwave Treatment ◽  
Thermal Runaway ◽  
X Zeolite ◽  
Degradation Degree ◽  
Lower Heating

Na-X zeolite easily caused a thermal runaway by microwave radiation of 500W but Ca-X zeolite merely reached ca. 300°C. Mixtures of Ca-X and Na-X reached lower heating temperature with increasing the content of Ca-X and the heating temperature could be controlled (>300°C) by adjusting the content. Since water in X zeolite almost completely desorbs by 400°C, conditions realizing the heating temperature of ca. 400°C were studied. The mixture with the ratio of Ca-X/Na-X=0.9/0.1 was quickly heated to ca. 400°C by the radiation of 10-20 min in the 500 W power and reached the dehydration state up to >90 %. A degradation degree of adsorption capacity of the mixture for water was examined after two and three treatments with the microwave heating. The average degradation degree was 1.4 % per treatment. The properties of the zeolite desiccant with microwave treatment were compared with those of commercial CaCl2 desiccant. It was found that the zeolite desiccant is superior to the commercial desiccant and an application of zeolite to a domestic reusable desiccant, through the heating technique, is promising.

scholarly journals Features of technological processing of seeds with an electromagnetic field of microwave before sowing

2021 ◽  
Vol 845 (1) ◽  
pp. 012142
Author(s):  
S V Vendin
Keyword(s):  
Microwave Heating ◽  
Crop Production ◽  
Heating Temperature ◽  
Experimental Studies ◽  
Microwave Treatment ◽  
Microwave Exposure ◽  
Soil Preparation ◽  
Technological Processing ◽  
The Impact ◽  
The Relationship

Abstract To increase the efficiency of crop production in the arsenal of the agronomic service there is a number of techniques, methods and technologies that reveal the potential of agricultural plants for all stages of production, starting with soil preparation, selection and preparation of seeds for sowing, agrotechnological measures during the growing season, harvesting technologies, storage and processing of products. The article presents the results of experimental studies on the use of the energy of ultra-high frequency electromagnetic fields for pre-sowing treatment of lupine seeds in order to increase their germination. Revealed the relationship between the parameters of microwave exposure and seed germination. The areas of modes where microwave treatment allows to increase germination, as well as areas of modes in which the impact does not reach the planned effect, or has a negative (depressing) effect, have been determined. Recommendations are given for ensuring the optimal modes of microwave processing and ensuring control of the parameters of the technological process. Based on the results obtained, it can be reliably asserted that the region of microwave treatment of lupine seeds, with a result exceeding the control values, is observed at exposure in the range from 50 to 60 s and at a specific microwave power of exposure from 1.0 to 1.17 kW/kg. The best result of an increase in germination by 1.5% was obtained at 60 s and 1.17 kW/kg. When treating seeds, it is recommended to maintain an average microwave heating rate of 0.50 °C/s until an average microwave heating temperature of 51.5 °C is reached.

DEVICE AND METHOD FOR CONTROLLING MICROWAVE SEED TREATMENT ON A CONVEYOR BELT

2021 ◽  
pp. 59-65
Author(s):  
ALEKSANDR N. MALAKHOV ◽  
Keyword(s):  
Microwave Heating ◽  
Electromagnetic Waves ◽  
Heating Temperature ◽  
Dielectric Materials ◽  
Microwave Treatment ◽  
Conveyor Belt ◽  
Microwave Devices ◽  
Microwave Source ◽  
Processing Modes ◽  
High Yields

The sowing qualities of seeds – such as germination, germination energy, weight of 1000 seeds, etc., are the factors ensuring high yields of agricultural crops. Technological methods of seed and grain treatment with the UHF MEMF (microwave electromagnetic fi eld of ultrahigh frequency) energy involve the use of various types of microwave devices, diff ering both in operating principle and in design. In fact, the process of microwave treatment of seeds is similar to the process of heat treatment of dielectric materials. Therefore, depending on the goal of treatment, microwave devices should provide some kind of selectivity of microwave heating, a high conversion factor of microwave energy into thermal energy, uniformity of microwave treatment of the bulk of material, protection of the microwave generator and electromagnetic safety. During the microwave treatment of seeds, it is important to ensure uniform treatment of the bulk of seeds and automatically maintain optimal treatment modes (microwave heating modes). An installation design is proposed for microwave treatment of seeds. A specifi c feature of the proposed design is that seeds are processed on a moving belt under an emitter with the process control and regulation according to the speed and fi nal heating temperature. Moreover, the microwave source intensity depends on the load (a layer of seeds on the conveyor belt). The authors also propose an algorithm for the microprocessor control of the device. Thus, the proposed design of the installation for treating seeds in a layer under the emitter on a moving conveyor belt, as well as the technological algorithm for matching the microwave source with the load ensure the compliance with the processing modes in strictly specifi ed ranges of the fi nal temperature and microwave heating rate of the material, as well as protect the microwave source from refl ected electromagnetic waves.

scholarly journals Microwaves and Heterogeneous Catalysis: A Review on Selected Catalytic Processes

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 246 ◽  
Author(s):  
Vincenzo Palma ◽  
Daniela Barba ◽  
Marta Cortese ◽  
Marco Martino ◽  
Simona Renda ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Energy Saving ◽  
Microwave Heating ◽  
Microwave Radiation ◽  
Heterogeneous Catalysts ◽  
Conventional Heating ◽  
Specific Effects ◽  
Natural Choice ◽  
Future Challenges ◽  
Catalyzed Reactions

Since the late 1980s, the scientific community has been attracted to microwave energy as an alternative method of heating, due to the advantages that this technology offers over conventional heating technologies. In fact, differently from these, the microwave heating mechanism is a volumetric process in which heat is generated within the material itself, and, consequently, it can be very rapid and selective. In this way, the microwave-susceptible material can absorb the energy embodied in the microwaves. Application of the microwave heating technique to a chemical process can lead to both a reduction in processing time as well as an increase in the production rate, which is obtained by enhancing the chemical reactions and results in energy saving. The synthesis and sintering of materials by means of microwave radiation has been used for more than 20 years, while, future challenges will be, among others, the development of processes that achieve lower greenhouse gas (e.g., CO2) emissions and discover novel energy-saving catalyzed reactions. A natural choice in such efforts would be the combination of catalysis and microwave radiation. The main aim of this review is to give an overview of microwave applications in the heterogeneous catalysis, including the preparation of catalysts, as well as explore some selected microwave assisted catalytic reactions. The review is divided into three principal topics: (i) introduction to microwave chemistry and microwave materials processing; (ii) description of the loss mechanisms and microwave-specific effects in heterogeneous catalysis; and (iii) applications of microwaves in some selected chemical processes, including the preparation of heterogeneous catalysts.

Methods of temperature measurement in microwave heating technologies

2021 ◽  
pp. 20-28
Author(s):  
Boris A. Lapshinov
Keyword(s):  
Temperature Measurement ◽  
Microwave Heating ◽  
Microwave Radiation ◽  
Electromagnetic Fields ◽  
Optical Measurement ◽  
Measurement Methods ◽  
Heating Systems ◽  
Measurement Systems ◽  
Processed Material ◽  
Spectral Pyrometry

In industrial technological processes associated with the heating of the processed material by microwave radiation, it is necessary to measure the temperatures of objects. Methods for measuring temperatures in the fields of technology using microwave heating systems are considered. The main possibilities, disadvantages and limitations of the used contact and non-contact (optical) measurement methods are determined. The requirements for temperature measurement systems under conditions of exposure to strong electromagnetic fields are listed. The possibilities of the spectral pyrometry method are especially noted.

scholarly journals SYNTHESIS OF 3-TERT-BUTYL-9-R-PYRIMIDO[4,5:3,4]PYRAZOLO[5,1-C][1,2,4]TRIAZINE-4(6H),11(10H)- DIONES AT CONDITIONS OF MICROWAVE RADIATION

2018 ◽  
Vol 59 (3) ◽  
pp. 74
Author(s):  
Lyudmila M. Mironovich ◽  
Pavel V. Afanas'yev ◽  
Anna Yu. Podol’nikova
Keyword(s):  
Microwave Heating ◽  
Microwave Radiation ◽  
Reaction Kinetic ◽  
Kinetic Characteristics ◽  
Tert Butyl

3-tert-butyl-9-R-pyrimido[4’,5’:3,4]pyrazolo[5,1-c][1,2,4]triazine-4(6H),11(10H)-diones was synthesized at the conditions of microwave radiation. The reaction kinetic characteristics were obtained under conditions of thermal and microwave heating.

scholarly journals Preparation, Characterization and Adsorption Potential of Grainy Halloysite-CNT Composites for Anthracene Removal from Aqueous Solution

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 890 ◽  
Author(s):  
Gabriela Kamińska ◽  
Mariusz Dudziak ◽  
Edyta Kudlek ◽  
Jolanta Bohdziewicz
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Heating Temperature ◽  
Langmuir Model ◽  
Adsorption Potential ◽  
Adsorption Sites ◽  
Enhanced Adsorption

Grainy Hal-CNT composites were prepared from powder halloysite nanoclay (Hal) and carbon nanotubes (CNTs). The effect of the amount and type of CNTs, as well as calcination temperature on morphology and properties of Hal-CNT composites and their adsorption capacity of anthracene (ANT), were studied. The surface topography of granules was heterogenous, with cracks and channels created during granulation of powder clay and CNTs. In FTIR, spectra were exhibited only in the bands arising from halloysite, due to its dominance in the granules. The increase in the heating temperature to 550 °C resulted in mesoporosity/macroporosity of the granules, the lowest specific surface area (SSA) and poorest adsorption potential. Overall, SSA of all Hal-CNT composites were higher than raw Hal, and by itself, heated halloysite. The larger amount of CNTs enhanced adsorption kinetics due to the more external adsorption sites. The equilibrium was established with the contact time of approximately 30 min for the sample Hal-SWCNT 85:15, while the samples with loading 96:4, it was 60–90 min. Adsorption isotherms for ANT showed L1 type, which is representative for the sorbents with limited adsorption capacity. The Langmuir model described the adsorption process, suggesting a monolayer covering. The sample Hal-SWCNT 85:15 exhibited the highest adsorption capacity of ANT, due to its highest SSA and microporous character.

An Alternative Technology for the Manufacture of Rubber Articles from Motor Vehicle Tyre Recycling Products

2018 ◽  
Vol 45 (4) ◽  
pp. 167-170
Author(s):  
V.F. Kablov ◽  
A.V. Perfil'ev ◽  
V.P. Shabanova ◽  
A.A. Perfil'ev
Keyword(s):  
Microwave Heating ◽  
Microwave Radiation ◽  
Motor Vehicle ◽  
Powder Technology ◽  
Considerable Reduction ◽  
Small Enterprises ◽  
Rubber Industry ◽  
Alternative Technology

The prospects of using powder technology to manufacture rubber articles and the features of different variants of powder technology using powder and block rubbers are considered. Examples of the practical use of powder technology at enterprises of the rubber industry are given. Powder press technology for the manufacture of rubber articles from rubber crumbs obtained by recycling used tyres is presented. Variants for the activation of composites to be pressed are examined. It is shown that the use of microwave radiation to activate rubber crumbs directly before the manufacture of articles from them makes it possible to produce products with improved properties. The strength of vulcanisates obtained from rubber crumbs activated by microwave radiation is 30% higher owing to the fact that, in the case of microwave heating, the rubber crumbs are heated evenly throughout the article and there is a considerable reduction in the vulcanisation time. Powder press technology is recommended for the manufacture of various moulded rubber articles at small enterprises not possessing standard rubber mixers.

scholarly journals Microwave treatment of rice

2013 ◽  
Vol 19 (No. 2) ◽  
pp. 62-66 ◽  
Author(s):  
J. Kaasová ◽  
P. Kadlec ◽  
Z. Bubník ◽  
V. Pour
Keyword(s):  
Microwave Heating ◽  
Starch Content ◽  
Initial Moisture Content ◽  
Microwave Treatment ◽  
Drying Time ◽  
Treated Sample ◽  
System Temperature ◽  
Rice Drying ◽  
The Stability ◽  
Total Starch

The effect of microwave treatment on wet rice was studied. Power output used was 90, 160, 350 or 500 W; final heating temperatures were 40, 60 and 80°C; initial moisture content of rice was 11, 21 or 30%. Temperature of treated sample during microwave heating was measured by means of NoEMI fiber-optic temperature system. Temperature of rice gelatinization, expressed as alkali spreading values and total starch content, was used to evaluate the influence of microwave heating on physicochemical properties of rice. Drying time reduction and the stability of total starch content during microwave treatment of rice makes it possible to recommend the combination of microwave and conventional rice drying for further use.

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