scholarly journals Special Issue on “Microwave Applications in Chemical Engineering”

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 491
Author(s):  
Huacheng Zhu ◽  
Kama Huang ◽  
Junwu Tao
Keyword(s):  
Heating Rate ◽  
Microwave Heating ◽  
Chemical Reactions ◽  
Chemical Industry ◽  
Reaction Rate ◽  
Chemical Engineering ◽  
Special Issue ◽  
Fast Heating ◽  
Microwave Applications ◽  
By Products

Microwave heating has been widely used in the chemical industry because of its advantages, such as fast heating rate, selective and controllable heating, increasing reaction rate and reducing by-products in chemical reactions. The Special Issue contains research on microwave applications in chemical engineering.

scholarly journals Advances in Cryochemistry: Mechanisms, Reactions and Applications

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 750
Author(s):  
Lu-Yan An ◽  
Zhen Dai ◽  
Bin Di ◽  
Li-Li Xu
Keyword(s):  
Low Temperature ◽  
Chemical Reactions ◽  
Common Sense ◽  
Reaction Rate ◽  
Concentration Effect ◽  
Biological Products ◽  
Freeze Concentration ◽  
New Strategy ◽  
The 1960S

It is counterintuitive that chemical reactions can be accelerated by freezing, but this amazing phenomenon was discovered as early as the 1960s. In frozen systems, the increase in reaction rate is caused by various mechanisms and the freeze concentration effect is the main reason for the observed acceleration. Some accelerated reactions have great application value in the chemistry synthesis and environmental fields; at the same time, certain reactions accelerated at low temperature during the storage of food, medicine, and biological products should cause concern. The study of reactions accelerated by freezing will overturn common sense and provide a new strategy for researchers in the chemistry field. In this review, we mainly introduce various mechanisms for accelerating reactions induced by freezing and summarize a variety of accelerated cryochemical reactions and their applications.

Synthesis of Oximes in the Microwave Oven

1992 ◽  
Vol 57 (11) ◽  
pp. 2407-2412 ◽  
Author(s):  
Monika Puciová ◽  
Štefan Toma
Keyword(s):  
Microwave Heating ◽  
Reaction Rate ◽  
Microwave Oven ◽  
Effect Of Solvents

The synthesis of a broad range of oximes has been studied. It was found that the application of microwave heating enhanced dramatically the reaction rate, and practically quantitative yields of oximes were isolated after less than 1-min heating in the most cases. The effect of solvents on the course of the reaction was also studied.

Microwave Nitrudation of Silicon Compacts Utilizing a Temperature Gradient

1992 ◽  
Vol 287 ◽  
Author(s):  
Jeffrey J. Thomas ◽  
Hamlin M. Jennings ◽  
D. Lynn Johnson
Keyword(s):  
Silicon Nitride ◽  
Temperature Gradient ◽  
Microwave Heating ◽  
Reaction Rate ◽  
Nitrogen Depletion

ABSTRACTSilicon compacts nitrided utilizing the temperature gradient inherent to microwave heating were more fully converted to silicon nitride than was possible with similar compacts nitrided isothermally. Although nitrogen depletion prevented the reaction rate in the center from exceeding that at the surface, the temperature gradient partially counteracted the effect of nitrogen depletion. Thus the microwave-heated specimens could be nitrided fully before the reduction in porosity that accompanies the reaction eliminated the diffusion of nitrogen into the compact.

scholarly journals Research on Electromagnetic Sensitivity Properties of Sodium Chloride during Microwave Heating

2020 ◽  
Vol 39 (1) ◽  
pp. 54-62
Author(s):  
Hua Chen ◽  
Junjiang Chen ◽  
Weijun Wang ◽  
Huan Lin
Keyword(s):  
Sodium Chloride ◽  
Electric Field ◽  
Water Content ◽  
Heating Rate ◽  
Microwave Heating ◽  
Resonant Cavity ◽  
Relative Dielectric Constant ◽  
Heating System ◽  
Heating Process ◽  
Heating Efficiency

AbstractThe multimode resonant cavity is the most common cavity. The material often shows on selective heating performance during the heating process due to the effect of microwave heating having a closely relationship with the electromagnetism parameters. This paper is based on finite difference time domain method (FDTD) to establish the electromagnetic-thermal model. The electromagnetic sensitivity property parameters of sodium chloride including relative dielectric constant, loss angle tangent and water content of sodium chloride is studied during the heating and drying process. The heating rate and the electric field distribution of sodium chloride, at the different water content, were simulated with the electromagnetic characteristic parameters changing. The results show that with the electromagnetic sensitivity property parameters varying, the electric field strength, heating rate and steady-state temperature of the heating material will all have a variety in the cavity. Some measures are proposed to improve the heating efficiency and ensure the stability of the microwave heating system in the industrial application.

Effect of Microwave Heating Rate on Maltose Production in Sweetpotato

1994 ◽  
pp. 504-506
Author(s):  
Tsuyoshi Nakai ◽  
Jun Sawai ◽  
Atsushi Hashimoto ◽  
Taijirou Honda ◽  
Masaru Shimizu
Keyword(s):  
Heating Rate ◽  
Microwave Heating

scholarly journals Existing problems and measures in safety management of chemical engineering

2018 ◽  
Author(s):  
Yuepeng Liu ◽  
Zhigang Zhang ◽  
Quan Yang ◽  
Qiang Zhang ◽  
Zhen’an Liu
Keyword(s):  
Economic Development ◽  
Chemical Industry ◽  
Chemical Engineering ◽  
Safety Management ◽  
Pollution Prevention ◽  
Construction Process ◽  
Technical Problems ◽  
Engineering Construction ◽  
Technical Requirements ◽  
Management Personnel

For a country, the industry is a very important system, the embodiment of the country's comprehensive national strength, the country's economic development level and the development of science and technology level has direct impact on industry. The development of chemical industry also has great impetus to the national economic development. The technical requirements for chemical engineering are particularly high. Because of the danger of the chemical itself, safety becomes the first thing to notice in the construction process. In order to prevent the occurrence of danger in the actual construction process, the safety of chemical engineering construction is made, and the effective safety management is the most critical step. A reliable safety management is the guarantee for the smooth construction of the construction, so the early safety management becomes the key to the development of the chemical industry. Chemical engineering is an extremely complex and changeable system, and the kinds of problems involved are very many, which requires the construction personnel to pay more attention to ensure the safety. In order to implement the safety management measures in the process of chemical engineering construction, it is necessary for the management personnel to strictly control the whole construction process. In case of any problem, we should deal with it in a timely manner and pay more attention to the details. We should pay attention to fire prevention, pollution prevention and anti-explosion prevention. Technical personnel should pay more attention to technical problems and eliminate safety hazards. The construction company must also strengthen the personal quality of the project management personnel and other issues. It is necessary to examine personal responsibility and safety awareness and avoid unnecessary losses caused by various construction safety issues to the company[1].

scholarly journals The Effect of Ultra-Fast Heating on the Microstructure, Grain Size and Texture Evolution of a Commercial Low-C, Medium-Mn DP Steel

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 877 ◽  
Author(s):  
Alexandros Banis ◽  
Eliseo Hernandez Duran ◽  
Vitaliy Bliznuk ◽  
Ilchat Sabirov ◽  
Roumen H. Petrov ◽  
...  
Keyword(s):  
Grain Size ◽  
Heating Rate ◽  
Rapid Heating ◽  
Texture Evolution ◽  
Heating Time ◽  
Manganese Steel ◽  
Low Carbon ◽  
Fast Heating ◽  
Suitable Alternative ◽  
Heated Sample

The effect of ultra-fast heating on the microstructures of steel has been thoroughly studied over the last year as it imposes a suitable alternative for the production of ultra high strength steel grades. Rapid reheating followed by quenching leads to fine-grained mixed microstructures. This way the desirable strength/ductility ratio can be achieved while the use of costly alloying elements is significantly reduced. The current work focuses on the effect of ultra-fast heating on commercial dual phase grades for use in the automotive industry. Here, a cold-rolled, low-carbon, medium-manganese steel was treated with a rapid heating rate of 780 °C/s to an intercritical peak temperature (760 °C), followed by subsequent quenching. For comparison, a conventionally heated sample was studied with a heating rate of 10 °C/s. The initial microstructure of both sets of samples consisted of ferrite, pearlite and martensite. It is found that the very short heating time impedes the dissolution of cementite and leads to an interface-controlled α → γ transformation. The undissolved cementite affects the grain size of the parent austenite grains and of the microstructural constituents after quenching. The final microstructure consists of ferrite and martensite in a 4/1 ratio, undissolved cementite and traces of austenite while the presence of bainite is possible. Finally, it is shown that the texture is not strongly affected during ultra-fast heating, and the recovery and recrystallization of ferrite are taking place simultaneously with the α → γ transformation.

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