Thermal Pyrolysis of Polyethylene in Fluidized Beds: Review of the Influence of Process Parameters on Product Distribution

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
K. Suresh Kumar Reddy ◽  
Pravin Kannan ◽  
Ahmed Al Shoaibi ◽  
C. Srinivasakannan
Keyword(s):  
Fluidized Bed ◽  
Process Parameters ◽  
Fluidized Beds ◽  
Pyrolysis Temperature ◽  
Liquid Product ◽  
Product Distribution ◽  
Major Influence ◽  
Process Conditions ◽  
Influence Of Process Parameters ◽  
Thermal Pyrolysis

The present work is an attempt to compile and analyze the most recent literature pertaining to thermal pyrolysis of plastic waste using fluidized bed reactors. The review is short owing to the small number of work reported in the open literature in particular to the fluidized beds. Although works on pyrolysis are reported in fixed beds, autoclaves, and fluidized beds, vast majority of them address to the utilization of fluidized bed due to their advantages and large scale adaptability. The pyrolysis temperature and the residence time are reported to have major influence on the product distribution, with the increase in pyrolysis temperature favoring gas production, with significant reduction in the wax and oil. The pyrolysis gas generally contains H2, CO, CO2, CH4, C2H4, C2H6 while liquid product comprises benzene, toluene, xylene, styrene, light oil, heavy oil, and gasoline with the variations depending on process conditions. The effects of other process parameters, namely fuel feed rate, fuel composition, and fluidizing medium have been reviewed and presented.

scholarly journals Subcritical Water Extraction of Chestnut Bark and Optimization of Process Parameters

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2774 ◽  
Author(s):  
Tanja Gagić ◽  
Željko Knez ◽  
Mojca Škerget
Keyword(s):  
Process Parameters ◽  
Subcritical Water ◽  
Extraction Process ◽  
Extraction Yield ◽  
Water Extraction ◽  
Bark Extract ◽  
Total Phenol Content ◽  
Process Conditions ◽  
Subcritical Water Extraction ◽  
Influence Of Process Parameters

The aim of the work was the optimization of the subcritical water extraction process of chestnut bark using Box–Behnken response surface methodology. The influence of process parameters, such as temperature, extraction time and solvent-solid ratio, on extraction yield, yield of the main compounds, total phenol content, total tannin content and antioxidant activity has been investigated. The identified compounds were ellagic and gallic acids, ellagitannins (vescalagin, castalagin, 1-o-galloyl castalagin, vescalin and castalin), sugars (maltose, glucose, fructose and arabinose) and sugar derivatives (5-HMF, furfural and levulinic acid). Finally, the optimal process conditions for obtaining the bark extract highly rich in ellagic acid and with satisfactory levels of total phenols and total tannins have been determined.

Preparation of high-oriented molybdenum thin films using DC reactive magnetronsputtering

2017 ◽  
Vol 31 (07) ◽  
pp. 1750059 ◽  
Author(s):  
Zhengguo Shang ◽  
Dongling Li ◽  
She Yin ◽  
Shengqiang Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Roughness ◽  
Process Parameters ◽  
Gas Flow ◽  
Lattice Mismatch ◽  
Practical Significance ◽  
Process Time ◽  
Process Conditions ◽  
Influence Of Process Parameters

Since molybdenum (Mo) thin film has been used widely recently, it attracts plenty of attention, like it is a good candidate of back contact material for CuIn[Formula: see text]Ga[Formula: see text]Se[Formula: see text]S[Formula: see text] (CIGSeS) solar cells development; thanks to its more conductive and higher adhesive property. Besides, molybdenum thin film is an ideal material for aluminum nitride (AlN) thin film preparation and attributes to the tiny (−1.0%) lattice mismatch between Mo and AlN. As we know that the quality of Mo thin film is mainly dependent on process conditions, it brings a practical significance to study the influence of process parameters on Mo thin film properties. In this work, various sputtering conditions are employed to explore the feasibility of depositing a layer of molybdenum film with good quality by DC reactive magnetron sputtering. The influence of process parameters such as power, gas flow, substrate temperature and process time on the crystallinity and crystal orientation of Mo thin films is investigated. X-ray diffraction (XRD) measurements and atomic force microscope (AFM) are used to characterize the properties and surface roughness, respectively. According to comparative analysis on the results, process parameters are optimized. The full width at half maximum (FWHM) of the rocking curves of the (110) Mo is decreased to 2.7[Formula: see text], and the (110) Mo peaks reached [Formula: see text] counts. The grain size and the surface roughness have been measured as 20 Å and 3.8 nm, respectively, at 200[Formula: see text]C.

scholarly journals Experimental Study on Three-Dimensional Microstructure Copper Electroforming Based on 3D Printing Technology

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 887
Author(s):  
Yuanyuan Wu ◽  
Shuangqing Qian ◽  
Hua Zhang ◽  
Yong Zhang ◽  
Hongbei Cao ◽  
...  
Keyword(s):  
3D Printing ◽  
Process Parameters ◽  
Current Density ◽  
Three Dimensional ◽  
Machining Process ◽  
Optimum Process ◽  
Process Conditions ◽  
Influence Of Process Parameters ◽  
Printing Technology ◽  
3D Printing Technology

In order to fabricate three-dimensional metal microstructures, a combined machining process based on 3D printing technology and electroforming technology is proposed. Firstly, a substrate with microstructures is fabricated by 3D printing technology, and then the microstructures were fabricated by electroforming technology. The influence of process parameters such as current density, distance between electrodes and pulse current duty cycle on the electroformed layer were studied and analyzed. It was determined that the peak current density 6A/dm2, the void ratio 20%, and the distance between electrodes 40 mm were the optimum process conditions of electroforming experiment. The electroforming experiments of different microstructures were carried out with the optimum process parameters.

scholarly journals THEORETICAL STUDY OF GRANULATION KINETICS IN A BATCH FLUIDIZED BED

2017 ◽  
Vol 60 (5) ◽  
pp. 81
Author(s):  
Andrey V. Mitrofanov ◽  
Vadim E. Mizonov ◽  
Katia Tannous ◽  
Lev N. Ovchinnikov
Keyword(s):  
Markov Chain ◽  
Fluidized Bed ◽  
Process Parameters ◽  
Theoretical Study ◽  
Transition Probabilities ◽  
Markov Chain Model ◽  
Chain Model ◽  
Time Step ◽  
Influence Of Process Parameters ◽  
Superficial Gas Velocity

The objective of the study is to build a simple but informative model to estimate qualitatively the influence of process parameters on granulation kinetics in a batch fluidized bed. A Markov chain approach is used to build the model. The height of fluidized bed reactor is separated into a certain number of perfectly mixed cells, and two parallel chains of such cells are introduced: one chain for original particles and another chain for already granulated particles. The particles can move stochastically along their chains and transit from one chain to another due to their size enlargement during granulation. It is supposed that the granulation itself occurs only in the cell of original particles where a binder suspension is supplied to. The volume of suspension, which enters the cell during the time step, is spread over the original particles that can be covered by the suspension up to their desired size. These particles transit to the neighboring cell of another chain for already granulated particles. Then the both sorts of particles move along their chains according to corresponding matrices of transition probabilities. This “could” model can be easily combined with the Markov chain model of drying in fluidized bed developed in our previous works. The numerical experiments with the developed model allowed qualitative estimating the influence of the process parameters on the granulation kinetics. The existence of the optimum superficial gas velocity that provides the maximum rate of granulation is shown. For citation:Mitrofanov A.V., Mizonov V.E., Tannous K., Ovchinnikov L.N. Theoretical study of granulation kinetics in a batch fluidized bed. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 81-87

Fluidized bed technology for biooil production: Review

2015 ◽  
Vol 4 (2) ◽  
pp. 423-427
Author(s):  
Mythili Rangasamy ◽  
P Venkatachalam ◽  
P Subramanian
Keyword(s):  
Fluidized Bed ◽  
Process Parameters ◽  
Circulating Fluidized Bed ◽  
Fast Pyrolysis ◽  
Liquid Product ◽  
Fluidized Bed Reactors ◽  
Tubular Reactors ◽  
Rotating Cone

Fast pyrolysis is an emerging technique by which a liquid product, biooil is formed. The fast pyrolysis can be done using various reactors such as fluidized bed reactors, transported and circulating fluidized bed reactors, ablative and vacuum reactors, tubular reactors, microwave pyrolytic reactors,auger system and rotating cone reactors. Among them fluidized bed system is a well understood technology and available for the commercialization of fast pyrolysis. In this review, the process parameters in fluidized bed system that enhance the biooil production were reviewed. Utilization of various feedstocks for biooil production and the characteristics of biooil that mainly affect the utilization were presented.  

Using Smoothed Particle Hydrodynamics to Examine Influence of Process Parameters on Ultrasonic Machining

2014 ◽  
Vol 8 (6) ◽  
pp. 855-863 ◽  
Author(s):  
Jingsi Wang ◽  
◽  
Keita Shimada ◽  
Masayoshi Mizutani ◽  
Tsunemoto Kuriyagawa
Keyword(s):  
Process Parameters ◽  
Smoothed Particle Hydrodynamics ◽  
Soda Lime Glass ◽  
Process Conditions ◽  
Ultrasonic Machining ◽  
Machining Performance ◽  
Influence Of Process Parameters ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Simulation Results

The initiation and propagation of cracks generated on a work surface during UltraSonic Machining (USM) were simulated using Smoothed Particle Hydrodynamics (SPH). Different abrasive materials, tool materials, and abrasive sizes were used in this simulation. The distribution and size of the calculated cracks were found to be strongly influenced by different process conditions. According to the simulation results, using tools with a lower yield strength and slurry comprising softer and smaller abrasives decreases the crack size. Experiments were conducted to drill deep blind holes in soda-lime glass by USM and observe the cracks remaining on the machined surfaces. The experimental results agreed well with the simulation results. This work was the first to visualize the crack formation during USM under different process parameters with the SPH method. The results may be very useful for improving the machining performance of the USM process.

Experimental and Numerical Analysis of Liquid-Forming

2015 ◽  
Vol 651-653 ◽  
pp. 842-847 ◽  
Author(s):  
Johannes Zimmer ◽  
Daniel Klein ◽  
Markus Stommel
Keyword(s):  
Process Parameters ◽  
Temperature Drop ◽  
Liquid Product ◽  
Forming Process ◽  
Molding Process ◽  
Influence Of Process Parameters ◽  
Inertia Effects ◽  
Thermally Induced ◽  
Blow Molding ◽  
Stretch Blow Molding

The packaging of liquid products is conventionally realized by using two production stages, which are the stretch blow molding and the filling. In the stretch blow molding process, hot polyethylene terephthalate (PET) preforms are inflated by pressurized air into a cavity to form plastic bottles. In a follow-up process, these packages are filled by a separate machine with the desired liquid product. In contrast to that, liquid-forming combines the blowing and filling stages by directly using the liquid product to form a plastic bottle. Through this substitution, two main challenges arise. Firstly, there are significant inertia effects through the liquid mass, leading to additional reaction forces and a spatially inhomogeneous pressure distribution inside the preform. Secondly, the heat transfer between preform and fluid is drastically increased. Because of this cooling effect, a specific combination of forming speed as well as initial preform and liquid temperatures is necessary to avoid thermally induced preform rupture. This is based on the fact that the formability of PET rapidly declines below its glass transition temperature (Tg). Consequently, a process control requires the knowledge of how the process parameters influence the preform cooling. In this paper, a numerical simulation of the liquid-forming process (LF) is introduced including the preform cooling during forming. In addition, the strain-dependent self-heating effect of PET is implemented. Process experiments under different parameter combinations are conducted using simplified bottle geometry. Through a comparison of the results from experiments and from simulation, the influence of process parameters on the temperature drop and thus on thermally induced failure is determined. In this way, process understanding and control are increased.

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