Structure Engineered g-C3N4Nano-Sheets by Switching the Pyrolysis Gas Atmosphere for Enhanced Photo-Catalytic Degradation

2017 ◽  
Vol 35 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Yuanyuan Chai ◽  
Qianqian Liu ◽  
Lu Zhang ◽  
Jia Ren ◽  
Wei-Lin Dai
2020 ◽  
Author(s):  
Yildirim İsmail Tosun

Heated Ca apatite slimes in microwave radiated salt slurries are one of the most promising technologies for advanced fuel energy storage with favorable economic potential and intrinsic properties. The development of solid pellet technology for molten salt is a key issue in the heat transport processing. The apathite phosphate, slurry salt in the slime-salt bath mixes was investigated under microwave radiation heating to result in insoluble sorbent fines dissolved in porous basket. The insoluble consists of noble metal fission products, such as Pb, Zn, Cu. In this study, there have been very few transport studies of wet steam alkali slurry (metal fines-molten alkali salt mixture). Bath ferrite/apatite particle size changed the heat conductivity to salt bath. A major reason is that the retention time in fixed film processes is longer than in solid–gas processes. This allows more time to the heat absorption for cracking to the desorbed persistent compounds. Furthermore, radiated ferrite by microwave allows a sufficient intimate contact between coal and biomass surface pores and gas atmosphere in the furnace due to more pyrolysis gas desorption. Bubbling slurry of sorbent porosity decreases while temperature decreases. There was a critical porous structure of bubbling sorbent bath which is a factor that determines to a great extent both the sorbent rate and degree of boiling it was found that, a porous slurry bath over 45% was more efficient with radiated a low amount ferrite below weight rate of 15% in microwave column.


2019 ◽  
Vol 284 ◽  
pp. 178-187 ◽  
Author(s):  
Xiwei Xu ◽  
Zonglin Li ◽  
Enchen Jiang
Keyword(s):  

Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann

Freeze-drying followed by heavy metal shadowing is a long established and straight forward approach to routinely study the structure of dehydrated macromolecules. Very thin specimens such as isolated membranes or single macromolecules are directly adsorbed on C-coated grids. After rapid freezing the grids are transferred into a suitable vacuum equipment for freeze-drying and heavy metal shadowing.To improve the resolution power of shadowing films we introduced shadowing at very low specimen temperature (−250°C). To routinely do that without the danger of contamination we developed in collaboration with Balzers an UHV (p≤10-9 mbar) machine (BAF500K, Fig.2). It should be mentioned here that at −250°C the specimen surface acts as effective cryopump for practically all impinging residual gas molecules from the residual gas atmosphere.Common high resolution shadowing films (Pt/C, Ta/W) have to be protected from alterations due to air contact by a relatively thick C-backing layer, when transferred via atmospheric conditions into the TEM. Such an additional C-coat contributes disturbingly to the contrast at high resolution.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 167-178 ◽  
Author(s):  
Xin Tong ◽  
Jiao Li ◽  
Jun Ma ◽  
Xiaoquan Chen ◽  
Wenhao Shen

Studies were undertaken to evaluate gaseous pollutants in workplace air within pulp and paper mills and to consider the effectiveness of photo-catalytic treatment of this air. Ambient air at 30 sampling sites in five pulp and paper mills of southern China were sampled and analyzed. The results revealed that formaldehyde and various benzene-based molecules were the main gaseous pollutants at these five mills. A photo-catalytic reactor system with titanium dioxide (TiO2) was developed and evaluated for degradation of formaldehyde, benzene and their mixtures. The experimental results demonstrated that both formaldehyde and benzene in their pure forms could be completely photo-catalytic degraded, though the degradation of benzene was much more difficult than that for formaldehyde. Study of the photo-catalytic degradation kinetics revealed that the degradation rate of formaldehyde increased with initial concentration fitting a first-order kinetics reaction. In contrast, the degradation rate of benzene had no relationship with initial concentration and degradation did not conform to first-order kinetics. The photo-catalytic degradation of formaldehyde-benzene mixtures indicated that formaldehyde behaved differently than when treated in its pure form. The degradation time was two times longer and the kinetics did not reflect a first-order reaction. The degradation of benzene was similar in both pure form and when mixed with formaldehyde.


2019 ◽  
Vol 5 (12) ◽  
pp. 37-46
Author(s):  
K. Chalov ◽  
Yu. Lugovoy ◽  
Yu. Kosivtsov ◽  
E. Sulman

This paper presents a study of the process of thermal degradation of crosslinked polyethylene. The kinetics of polymer decomposition was studied by thermogravimetry. Crosslinked polyethylene showed high heat resistance to temperatures of 400 °C. The temperature range of 430–500 °C was determined for the loss of the bulk of the sample. According to thermogravimetric data, the decomposition process proceeds in a single stage and includes a large number of fracture, cyclization, dehydrogenation, and other reactions. The process of pyrolysis of a crosslinked polymer in a stationary-bed metal reactor was investigated. The influence of the process temperature on the yield of solid, liquid, and gaseous pyrolysis products was investigated. The optimum process temperature was 500 °C. At this temperature, the yield of liquid and gaseous products was 85.0 and 12.5% (mass.), Respectively. Samples of crosslinked polyester decomposed almost completely. The amount of carbon–containing residue was 3.5% by weight of the feedstock. With increasing temperature, the yield of liquid products decreased slightly and the yield of gaseous products increased, but their total yield did not increase. For gaseous products, a qualitative and quantitative composition was determined. The main components of the pyrolysis gas were hydrocarbons C1–C4. The calorific value of pyrolysis gas obtained at a temperature of 500 °C was 17 MJ/m3. Thus, the pyrolysis process can be used to process crosslinked polyethylene wastes to produce liquid hydrocarbons and combustible gases.


Author(s):  
Emma Jakab ◽  
Zoltán Sebestyén ◽  
Bence Babinszki ◽  
Eszter Barta-Rajnai ◽  
Zsuzsanna Czégény ◽  
...  

SummaryThe thermo-oxidative decomposition of lovage (Levisticum officinale) and davana (Artemisia pallens) essential oils has been studied by pyrolysis-gas chromatography/mass spectrometry in 9% oxygen and 91% nitrogen atmosphere at 300 °C to simulate low-temperature tobacco heating conditions. Both lovage and davana oils contain numerous chemical substances; the main components of both oils are various oxygen-containing compounds. Isobenzofuranones are the most important constituents of lovage oil, and their relative intensity changed significantly during oxidative pyrolysis. (Z)-ligustilide underwent two kinds of decomposition reactions: an aromatization reaction resulting in the formation of butylidenephthalide and the scission of the lactone ring with the elimination of carbon dioxide or carbon monoxide. Davanone is the main component of davana oil, which did not decompose considerably during low-temperature oxidative pyrolysis. However, the relative yield of the second most intensive component, bicyclogermacrene, reduced markedly due to bond rearrangement reactions. Davana ether underwent oxidation reactions leading to the formation of various furanic compounds. The changes in the composition of both essential oils could be interpreted in terms of bond splitting, intramolecular rearrangement mechanisms and oxidation reactions of several constituents during low-temperature oxidative pyrolysis. The applied thermo-oxidative method was found to be suitable to study the stability of the essential oils and monitor the decomposition products under simulated tobacco heating conditions. In spite of the complicated composition of the essential oils, no evidence for interaction between the oil components was found. [Beitr. Tabakforsch. Int. 29 (2020) 27–43]


2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Markus Heryanto Langsa

<p>Penelitian ini bertujuan untuk menentukan senyawa organik khususnya organic karbon terlarut (DOC) dari dua spesies daun tumbuhan (<em>wandoo eucalyptus </em>and <em>pinus radiate, conifer</em>) yang larut dalam air selama periode 5 bulan leaching eksperimen. Kecepatan melarutnya senyawa organic ditentukan secara kuantitatif dan kualitatif menggunakan kombinasi dari beberapa teknik diantaranya Total Organic Carbon (TOC) analyser, Ultraviolet-Visible (UV-VIS) spektrokopi dan pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS).</p><p>Hasil analisis DOC dan UV menunjukkan peningkatan yang tajam dari kelarutan senyawa organic di awal periode pengamatan yang selanjutnya berkurang seiring dengan waktu secara eksponensial. Jumlah relatif senyawa organic yang terlarut tergantung pada luas permukaan, aktifitas mikrobiologi dan jenis sampel tumbuhan (segar atau kering) yang digunakan. Fluktuasi profil DOC dan UV<sub>254</sub> disebabkan oleh aktifitas mikrobiologi. Diperoleh bahwa daun kering lebih mudah terdegradasi menghasilkan senyawa organic dalam air dibandingkan dengan daun segar. Hasil pyrolysis secara umum menunjukkan bahwa senyawa hidrokarbon aromatic dan fenol (dan turunannya) lebih banyak ditemukan pada residue sampel setelah proses leaching kemungkinan karena adanya senyawa lignin atau aktifitas humifikasi mikrobiologi membuktikan bahwa senyawa-senyawa tersebut merupakan komponen penting dalam proses karakterisasi DOC.</p>


2019 ◽  
Vol 24 (4) ◽  
pp. 59-66
Author(s):  
E.S. Filatov

Corrosion behavior of metal alloys in a melt of potassium chloroaluminate (KAlCl4) was investigated. Metal aluminum was used as a protector for protection against continuous frontal corrosion. The equilibrium potentials of aluminum and the corrosion potential of the alloys were measured. The data were obtained to evaluate the corrosion ability of the system of molten salt of potassium chloroaluminate - gas (argon) by measuring the redox potential of the specified environment depending on the composition of the gas atmosphere above it, i.e. from impurities of water vapor, hydrochloric acid, oxygen and other, for example, carbonaceous gases. The calculations of the protection efficiency using the potential difference between the metal aluminum and the protected material were performed. The regularities of changes in the equilibrium potentials of aluminum from the temperature and concentration were established as the fundamental data for possible use at determining the composition ratio of potassium chlorides and aluminum in potassium chloroaluminate as input data for the development of a sensor of composition of chloroaluminate potassium.


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