carbonization temperature
Recently Published Documents


TOTAL DOCUMENTS

285
(FIVE YEARS 103)

H-INDEX

24
(FIVE YEARS 6)

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 62
Author(s):  
Xue Li ◽  
Peng Lou ◽  
Longquan Yang

Fe3O4@RF microspheres with different phenolic (RF) layer thicknesses are prepared by adjusting the polymerization time. With the prepared Fe3O4@RF as the precursor, Fe@C composite microspheres with rattle-like morphology are obtained through one-step controlled carbonization. This method simplifies the preparation of rattle-shaped microspheres from sandwich microspheres. Fe@C microspheres exhibit excellent microwave absorbing properties. The morphology and composition of the product are investigated depending on the effects of carbonization temperature, time and thickness of the RF layer. When the carbonization temperature is 700 °C, the carbonization time is 12 h and the polymer shell thickness is 62 nm, the inner hollow Fe3O4 is completely reduced to Fe. The absorption properties of the materials are compared before and after the reduction of Fe3O4. Both Fe@C-12 and Fe3O4@C-700 show excellent absorbing properties. When the filler content is 50%, the maximum reflection loss (RLmax) of the rattle-shaped Fe@C microspheres is −50.15 dB, and the corresponding matching thickness is 3.5 mm. At a thickness of 1.7 mm, the RLmax of Fe3O4@C-700 is −44.42 dB, which is slightly worse than that of Fe@C-12. Both dielectric loss and magnetic loss play a vital role in electromagnetic wave absorption. This work prepares rattle-shaped absorbing materials in a simple way, which has significance for guiding the construction of rattle-shaped materials.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7551
Author(s):  
Hui Jing ◽  
Zongnan Miao ◽  
Zhong Zeng ◽  
Hui Liu ◽  
Shengtai Zhou ◽  
...  

Lightweight carbon foams with excellent electromagnetic interference (EMI) shielding performance were prepared by carbonization process, using isocyanate-based polyimide foams as carbon precursors. The influence of carbonization temperature and graphene-doping on the morphological, electrical and EMI shielding effectiveness (SE) of corresponding carbon foams was studied in detail. Results showed that the addition of graphene was beneficial to the improvement of electrical conductivity and EMI shielding performance of carbon foams. The electrical conductivity of carbon foams increased with the carbonization temperature which was related to the increase of graphitization degree. Collapse of foam cells was observed at higher carbonization temperatures, which was detrimental to the overall EMI SE. The optimal carbonization temperature was found at 1100 °C and the carbon foams obtained from 0.5 wt% graphene-doped foams exhibited a specific EMI SE of 2886 dB/(g/cm3), which shows potential applications in fields such as aerospace, aeronautics and electronics.


2021 ◽  
Vol 2 (2) ◽  
pp. 298-307
Author(s):  
Alperay ALTIKAT ◽  
Mehmet Hakkı ALMA

The aim of this research was to determine the effects of different carbonization temperature, gas flow rate and heating rates on biochar's color change. Three different carbonization temperatures (400°C, 500°C, and 600°C), two different gas flow rates (0.2 l min-1 and 0.5 l min-1) and two different heating temperature rates (30°C min-1 and 60°C min-1) were used in the experiments. The color changes of biochar were examined utilizing the international approved L*, a*, b* system. Atriplex nitens Schkuhr was used as a biomass source in the experiments. High carbonization temperature and high gas flow rate caused a decrease in the “L” value of biochar. It is an indication that the color is getting darker, when the L value approaches zero. In the study, only the effect of gas flow rate on the "a" value was found to be statistically significant (P≤0.05). The increase in gas flow rate caused the biochar to become darker by increasing the deep red tone. Heating rate and gas flow speed significantly influenced the "b" values of biochar. The slow heating rate and high gas flow rates made the biochar color darker. At end of the research, it can be said that the biochar produced at high carbonization temperature, low heating rate and high gas flow rates will have darker tones.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Piotr Kamedulski ◽  
Malgorzata Skorupska ◽  
Pawel Binkowski ◽  
Weronika Arendarska ◽  
Anna Ilnicka ◽  
...  

AbstractThe manuscript presents results on the influence of external pressure on graphene exfoliation and subsequent 3D structuring by means of liquid-phase exfoliation. In contrast to known and applied exfoliation methods, the current study exploits the enhancement of splitting forces caused by the application of high pressure. The manufacturing pathway allowed to increase the surface area from 750 m2/g (nanoplatelets) to ca. 1100 m2/g (after 3D structuring). Electrochemical studies revealed that the 3D graphene materials were active in the oxygen reduction reaction (ORR). The outstanding ORR activity of 3D structured graphene materials should not be ascribed to heteroatom catalytic centers since such heteroatoms were successively removed upon increasing the carbonization temperature. XPS data showed that the presence of transition metals and nitrogen (usually regarded as catalytic centers) in G-materials was marginal. The results highlight the importance of structural factors of electrodes in the case of graphene-based materials for Zn–air batteries and ORR.


2021 ◽  
Author(s):  
Shuai Guo ◽  
DanDan Xu ◽  
Xin Guo ◽  
Xingcan Li ◽  
Chenchen Zhao

Abstract The harmful effects of improper sewage sludge (SS) treatment on the environment inspire the search for more benign sludge processing techniques such as hydrothermal carbonization (HTC); the abundant organic matter in SS is used for energy recovery. Herein, response surface methodology (RSM) was used to optimize the HTC-based preparation of SS hydrochar and its gasification performance. Specifically, the hydrochar yield, higher heating value (HHV), and gasification activity index were selected as optimization goals, while carbonization temperature (160–260°C), residence time (30–150 min), and acetic acid concentration (0–1.5 M) were selected as factors influencing the HTC process and CO2-assisted gasification performance. Carbonization temperature was the dominant parameter determining hydrochar yield, HHV, and gasification activity. The hydrochar yield (82.69%) and calorific value (7820.99 kJ kg−1) were maximized under comparatively mild conditions (160°C, 30 min, and 0.07 M acetic acid), whereas the gasification activity index (0.288 s−1) was maximized under harsher conditions (211.34°C, 88.16 min, and 1.58 M acetic acid). The obtained results help to guide the HTC of SS intended for gasification, thus promoting the development of this promising waste-to-energy technology, and may facilitate the design and further optimization of thermochemical SS conversion.


Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 228
Author(s):  
Wen-Tien Tsai ◽  
Tasi-Jung Jiang ◽  
Yu-Quan Lin ◽  
Hsuan-Lun Chang ◽  
Chi-Hung Tsai

The residue remaining after the water extraction of soapberry pericarp from a biotechnology plant was used to produce a series of biochar products at pyrolytic temperatures (i.e., 400, 500, 600, 700 and 800 °C) for 20 min plant was used to produce a series of biochar products. The effects of the carbonization temperature on the pore and chemical properties were investigated by using N2 adsorption–desorption isotherms, energy dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FTIR). The pore properties of the resulting biochar products significantly increased as the carbonization temperature increased from 700 to 800 °C. The biochar prepared at 800 °C yielded the maximal BET surface area of 277 m2/g and total pore volume of 0.153 cm3/g, showing that the percentages of micropores and mesopores were 78% and 22%, respectively. Based on the findings of the EDS and the FTIR, the resulting biochar product may be more hydrophilic because it is rich in functional oxygen-containing groups on the surface. These results suggest that soapberry pericarp can be reused as an excellent precursor for preparing micro-mesoporous biochar products in severe carbonization conditions.


Sign in / Sign up

Export Citation Format

Share Document