scholarly journals Conversion of automotive paint sludge to activated carbon via microwave pyrolysis technique for supercapacitor application

Author(s):  
Siti Shawalliah Idris ◽  
Muhammad Nasrul Bojy ◽  
Zakiuddin Januri

Conversion of waste to wealth has been one of the ways to reduce the volume of industrial waste to disposal site, hence reducing the impact to the environment. In this work, paint sludge from an automotive industry (APS) was converted into activated carbon through chemical activation (potassium hydroxide (KOH)) using microwave pyrolysis technique. The effect of power and radiation time on the produced activated carbon were investigated and characterised (carbon content, surface area, and pore volume) to identify the possibility of application as a supercapacitor. Potassium hydroxide activation of the APS char via microwave pyrolysis has shown that power level and radiation time has influenced the yield of the APS activated carbon. A longer radiation time and higher power supply has produced activated carbon having higher carbon contents, lower impurities, higher surface area and higher pore volume. Thus, the APS activated carbon obtained via microwave pyrolysis at power supply 1000 W and 45 minutes radiation time had produced the highest surface area and total pore volume of 434.3 m2/g and 0.2901 cm3/g, respectively. However, the produced activated carbon is not suitable for the supercapacitor application as the minimum surface area requirement must be more than 1000 m2/g. The pore size of the activated APS char produced in this study was in the range of mesopores size which was also considered very poor for supercapacitor application. The outcome of this research has shown that the produced activated carbon could otherwise be used for other application than a supercapacitor.

2021 ◽  
Vol 21 (2) ◽  
pp. 211
Author(s):  
Norakmalah Mohd Zawawi ◽  
Fazlena Hamzah ◽  
Harumi Veny ◽  
Miradatul Najwa Mohd Rodhi ◽  
Mahanim Sarif

This paper presents the utilization of bamboo residue from the chopstick industry as modified carbon (AC) for supercapacitor application.  Bamboo activated carbon (BAC) was activated using Potassium hydroxide (KOH) and assisted with microwave ultrasonic (Mw-U) irradiation to enhance the properties of bamboo activated carbon (BAC). Different microwave (Mw) power intensities of 100 W, 300 W, and 500 W at 30 minutes of retention time have been applied on activation and the carbonization process was conducted at temperature 800°C. The BAC was analyzed for the morphology using a scanning electron microscope and proximate and ultimate analysis. Then BAC with the higher surface area was subjected to the electrochemical analysis to determine the electrochemical properties. The study indicated Mw-U irradiation improved the morphology of the BAC, eliminated the impurity of the sample, and gave higher carbon content of BAC. The findings show that lower Mw-U irradiation power provided a higher surface area of BAC. The surface area of 646.87 m2/g and total pore volume of 2.8x10-1 cm3/g was obtained with a power intensity of Mw-U activation at 100 W. While, electrochemical properties, the specific capacitance (Cs) of BAC was 77 Fg-1 at 25 mVs-1 in 1 mol/L KOH of electrolyte for cyclic voltammetry (CV) which indicates the ability of the prepared BAC to be used as an electrode in supercapacitor application. This study determined that Mw-U irradiation can improve the properties of the bamboo during chemical activation and formed BAC that consists of supercapacitor properties.


2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1621
Author(s):  
Beini Zeng ◽  
Xungai Wang ◽  
Nolene Byrne

Cellulose beads were successfully prepared from waste denim using a dissolution-regeneration approach with ionic liquids as the dissolving solvent. Cellulose beads with different morphologies were achieved by altering the dissolving and coagulating solvents. The morphological differences were quantified by N2 physisorption. The impact of morphology on the cellulose beads’ potential application was investigated in the context of drug loading and release. The results show that the fibrous morphology showed a better loading capacity than the globular analogue due to its higher surface area and pore volume.


2016 ◽  
Vol 35 (6) ◽  
pp. 535-541 ◽  
Author(s):  
Hongying Xia ◽  
Jian Wu ◽  
Chandrasekar Srinivasakannan ◽  
Jinhui Peng ◽  
Libo Zhang

AbstractThe present work attempts to convert bamboo into a high surface area activated carbon via microwave heating. Different chemical activating agents such as KOH, NaOH, K2CO3 and Na2CO3 were utilized to identify a most suitable activating agent. Among the activating agents tested KOH was found to generate carbon with the highest porosity and surface area. The effect of KOH/C ratio on the porous nature of the activated carbon has been assessed. An optimal KOH/C ratio of 4 was identified, beyond which the surface area as well as the pore volume were found to decrease. At the optimized KOH/C ratio the surface area and the pore volume were estimated to be 3,441 m2/g and 2.093 ml/g, respectively, with the significant proportion of which being microporous (62.3%). Activated carbon prepared under the optimum conditions was further characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Activated carbons with so high surface area and pore volume are very rarely reported, which could be owed to the nature of the precursor and the optimal conditions of mixture ratio adopted in the present work.


2007 ◽  
Vol 561-565 ◽  
pp. 1719-1722 ◽  
Author(s):  
Chiravoot Pechyen ◽  
Duangdao Aht-Ong ◽  
Duangduen Atong ◽  
Viboon Sricharoenchaikul

Char derived from pyrolysis of physic nut waste at 400-800°C was used for the preparation of activated carbon by chemical impregnation of phosphoric acid and potassium hydroxide. The original char exhibited the BET surface area in the range of 120-250 m2·g-1. The surface area increased to 480 and 532 m2·g-1 when activated with H3PO4 and KOH, respectively. Equilibrium adsorption data was found to be best represented by the Langmuir isotherm with maximum monolayer adsorption capacity of 560.13 mg·g-1 at 30°C. The adsorption capacity of the physic nut residue activated carbon was comparable to commercial activated carbon.


2015 ◽  
Vol 789-790 ◽  
pp. 66-70 ◽  
Author(s):  
Syarifah Nor Faizah Syed Abdul Rahman ◽  
Norazah Abdul Rahman ◽  
Siti Shawalliah Idris ◽  
Noor Fitrah Abu Bakar ◽  
Roslan Mokhtar ◽  
...  

Application of microwave absorber (MWA) does affect the yield of microwave pyrolysis process. In this study, activated carbon and graphite have been used as microwave absorbers and the results were then compared with the microwave pyrolysis process without microwave absorber. The yield of solid and liquid increased while the yield of gas decreased with the application of MWA. Chemical functional group inside MWA also affected by the microwave pyrolysis process and energy content of MWA slightly increased from 24.54 MJ/kg to 29.57 MJ/kg and 32.17 MJ/kg to 32.24 MJ/kg for activated carbon and graphite, respectively.


2019 ◽  
Vol 2 (3) ◽  
pp. 1205-1209
Author(s):  
Hasan Sayğılı

The influence of carbonization temperature (CT) on pore properties of the prepared activated carbon using lentil processing waste product (LWP) impregnated with potassium carbonate was studied. Activated carbons (ACs) were obtained by impregnation with 3:1 ratio (w/w) K2CO3/LWP under different carbonization temperatures at 600, 700, 800 and 900 oC for 1h. Activation at low temperature represented that micropores were developed first and then mesoporosity developed, enhanced up to 800 oC and then started to decrease due to possible shrinking of pores. The optimum temperature for LWP was found to be around 800 oC on the basis of total pore volume and the Brunauer-Emmett-Teller (BET) surface area. The optimum LWPAC sample was found with a CT of 800 oC, which gives the highest BET surface area and pore volume of 1875 m2/g and 0.995 cm3/g, respectively.


2019 ◽  
Vol 9 (10) ◽  
pp. 1977 ◽  
Author(s):  
Yu-Chun Chiang ◽  
Cheng-Yu Yeh ◽  
Chih-Hsien Weng

Polyacrylonitrile-based activated carbon fibers (ACFs), modified using potassium hydroxide (KOH) or tetraethylenepentamine (TEPA), were investigated for carbon dioxide (CO2) adsorption, which is one of the promising alleviation approaches for global warming. The CO2 adsorption isotherms were measured, and the values of isosteric heat of adsorption were calculated. The results showed that the KOH-modified ACFs exhibited a great deal of pore volume, and a specific surface area of 1565 m2/g was obtained. KOH activation made nitrogen atoms easily able to escape from the surface of ACFs. On the other hand, the surface area and pore volume of ACFs modified with TEPA were significantly reduced, which can be attributed to the closing or blocking of micropores by the N-groups. The CO2 adsorption on the ACF samples was via exothermic reactions and was a type of physical adsorption, where the CO2 adsorption occurred on heterogeneous surfaces. The CO2 uptakes at 1 atm and 25 °C on KOH-activated ACFs reached 2.74 mmole/g. This study observed that microporosity and surface oxygen functionalities were highly associated with the CO2 uptake, implying the existence of O-C coordination, accompanied with physical adsorption. Well cyclability of the adsorbents for CO2 adsorption was observed, with a performance decay of less than 5% over up to ten adsorption-desorption cycles.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (02) ◽  
pp. 63-69 ◽  
Author(s):  
Mamon Sarkar ◽  
Chao Tian ◽  
M. Sarwar Jahan

Activated carbon was prepared by phosphoric acid (H3PO4) activation of potassium hydroxide (KOH) pulping spent liquor lignin from rice straw and compared with KOH hydroxide activation. The process parameters, such as impregnation ratio, activation temperature, and activation time were varied and their effects on the yield of activated carbon and iodine number were studied. The activated carbon prepared by H3PO4 at 800°C for 60 min at an impregnation ratio of 2.5 reached a Brunauer-Emmett-Teller (BET) surface area of 1063 m2/g, including pore diameter of 14.4 nm, iodine number of 525 mg/g, and yield of 49.2%. Yield and BET surface area in KOH activation was much lower than that of H3PO4.


2004 ◽  
Vol 449-452 ◽  
pp. 217-220 ◽  
Author(s):  
Young Jae Lee ◽  
Jae Hyung Kim ◽  
Jang Soon Kim ◽  
Dong Bok Lee ◽  
Jae Chun Lee ◽  
...  

Activated carbon fibers were prepared from stabilized PAN-based fibers by chemical activation using potassium hydroxide at different concentration. The experimental data showed variations in specific surface area, microstructure by the activated carbon fibers. Specific surface area of about 2545 m2/g was obtained in the KOH/stabilized PAN-based fiber ratio of 1:1 at 800°. An abrupt reduction of specific surface area was observed in the experiments with the ratio of 3:1 of OH/stabilized PAN-based fiber, being dissimilar with the result of KOH/fiber ratios of 1:1 and 2:1 in the similar experiments. The high concentration of KOH led to the destruction of micropore walls instead of forming mesopores.


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