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Hamsan MH, Abdul Halim N, Demon SZN, Sa'aya NSN, Kadir MFZ, Abidin ZHZ, Ahmad Poad N, Abu Kasim NF, Razali NAM, Aziz SB, Ahmad KA, Miskon A, Nor NM. SCOBY-based bacterial cellulose as free standing electrodes for safer, greener and cleaner energy storage technology. Heliyon 2022; 8:e11048. [PMID: 36281392 PMCID: PMC9587280 DOI: 10.1016/j.heliyon.2022.e11048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 08/18/2022] [Accepted: 10/07/2022] [Indexed: 11/06/2022] Open
Abstract
Bacterial Cellulose (BC) derived from local market or symbiotic culture of bacteria and yeast (SCOBY) was employed as the polymer matrix for hydroxyl multi-walled carbon nanotube (MWCNT-OH)-based electrochemical double-layer capacitor (EDLC). Chitosan (CS)-sodium iodide (NaI)-glycerol (Gly) electrolyte systems were used as the polymer electrolyte. CS-NaI-Gly electrolyte possesses conductivity, potential stability and ionic transference number of (1.20 ± 0.26) × 10-3 S cm-2, 2.5 V and 0.99, respectively. For the electrodes, MWCNT-OH was observed to be well dispersed in the matrix of BC which was obtained via FESEM analysis. The inclusion of MWCNT-OH reduced the crystallinity of the BC polymeric structure. From EIS measurement, it was verified that the presence of MWCNT-OH decreased the electron transfer resistance of BC-based electrodes. Cyclic voltammetry (CV) showed that the shape of the CV plots changed to a rectangular-like shape plot as more MWCNT were added, thus verifying the capacitive behavior. Various amount of MWCNT-OH was used in the fabrication of the EDLC where it was discovered that more MWCNT-OH leads to a better EDLC performance. The EDLC was tested for 5000 complete charge-discharge cycles. The optimum performance of this low voltage EDLC was obtained with 0.1 g MWCNT where the average specific capacitance was 8.80 F g-1. The maximum power and energy density of the fabricated EDLC were 300 W kg-1 and 1.6 W h kg-1, respectively.
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Affiliation(s)
- Muhamad Hafiz Hamsan
- Department of Physics, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, Kuala Lumpur 57000, Malaysia
| | - Norhana Abdul Halim
- Department of Physics, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, Kuala Lumpur 57000, Malaysia,Corresponding author.
| | - Siti Zulaikha Ngah Demon
- Department of Physics, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, Kuala Lumpur 57000, Malaysia,Centre for Tropicalization, National Defence University of Malaysia, Sungai Besi Camp, Sungai Besi, 57000 Kuala Lumpur, Malaysia
| | - Nurul Syahirah Nasuha Sa'aya
- Faculty of Defence Science & Technology, National Defence University of Malaysia, Sg Besi Camp, Sungai Besi, Kuala Lumpur, Malaysia
| | - Mohd Fakhrul Zamani Kadir
- Physics Department, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia,University Malaya Centre for Ionic Liquids (UMCiL), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Zul Hazrin Zainal Abidin
- Centre for Ionics Universiti Malaya (C.I.U.M.), Department of Physics, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Nursaadah Ahmad Poad
- Faculty of Defence Science & Technology, National Defence University of Malaysia, Sg Besi Camp, Sungai Besi, Kuala Lumpur, Malaysia
| | - Nurul Farhana Abu Kasim
- Faculty of Defence Science & Technology, National Defence University of Malaysia, Sg Besi Camp, Sungai Besi, Kuala Lumpur, Malaysia
| | - Nur Amira Mamat Razali
- Faculty of Defence Science & Technology, National Defence University of Malaysia, Sg Besi Camp, Sungai Besi, Kuala Lumpur, Malaysia
| | - Shujahadeen B. Aziz
- Hameed Majid Advanced Polymeric Materials Research Lab., Physics Department, College of Science, University of Sulaimani, Qlyasan Street, Kurdistan Regional Government, Sulaimani 46001, Iraq,The Development Center for Research and Training (DCRT), University of Human Development, Kurdistan Region of Iraq, Sulaymaniyah 46001, Iraq
| | - Khairol Amali Ahmad
- Faculty of Engineering, National Defence University of Malaysia, Kem Sg Besi, Kuala Lumpur 57000, Malaysia
| | - Azizi Miskon
- Faculty of Engineering, National Defence University of Malaysia, Kem Sg Besi, Kuala Lumpur 57000, Malaysia
| | - Norazman Mohamad Nor
- Faculty of Engineering, National Defence University of Malaysia, Kem Sg Besi, Kuala Lumpur 57000, Malaysia
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Influence of Foam Morphology on Flow and Heat Transport in a Random Packed Bed with Metallic Foam Pellets-An Investigation Using CFD. MATERIALS 2022; 15:ma15113754. [PMID: 35683052 PMCID: PMC9181048 DOI: 10.3390/ma15113754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/18/2022] [Accepted: 05/21/2022] [Indexed: 12/04/2022]
Abstract
Open-cell metallic foams used as catalyst supports exhibit excellent transport properties. In this work, a unique application of metallic foam, as pelletized catalyst in a packed bed reactor, is examined. By using a wall-segment Computational Fluid Dynamics (CFD) setup, parametric analyses are carried out to investigate the influence of foam morphologies (cell size ϕ=0.45−3 mm and porosity ε=0.55−0.95) and intrinsic conductivity on flow and heat transport characteristics in a slender packed bed (N=D/dp=6.78) made of cylindrical metallic foam pellets. The transport processes have been modeled using an extended version of conventional particle-resolved CFD, i.e., flow and energy in inter-particle spaces are fully resolved, whereas the porous-media model is used for the effective transport processes inside highly-porous foam pellets. Simulation inputs include the processing parameters relevant to Steam Methane Reforming (SMR), analyzed for low (Rep~100) and high (Rep~5000) flow regimes. The effect of foam morphologies on packed beds has shown that the desired requirements contradict each other, i.e., an increase in cell size and porosity favors the reduction in pressure drop, but, it reduces the heat transfer efficiency. A design study is also conducted to find the optimum foam morphology of a cylindrical foam pellet at a higher Rep~5000, which yields ϕ = 0.45, ε = 0.8. Suitable correlations to predict the friction factor and the overall heat transfer coefficient in a foam-packed bed have been presented, which consider the effect of different foam morphologies over a range of particle Reynolds number, 100≤Rep≤5000.
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