Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process
Utilization of municipal sewage sludge as a feedstock for synthesizing biogenic multi-walled carbon nanotubes (MWCNTs) and recovering H2 via pyrolysis-chemical vapor deposition (CVD) was explored. The research centered on investigating the impact of X-Mo/MgO catalysts (X = Co, Fe, Ni, and X: Mo: MgO...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2024
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| Online Access: | https://hdl.handle.net/10356/180771 |
| _version_ | 1826109486688894976 |
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| author | Lu, Jintao Veksha, Andrei Lisak, Grzegorz |
| author2 | School of Civil and Environmental Engineering |
| author_facet | School of Civil and Environmental Engineering Lu, Jintao Veksha, Andrei Lisak, Grzegorz |
| author_sort | Lu, Jintao |
| collection | NTU |
| description | Utilization of municipal sewage sludge as a feedstock for synthesizing biogenic multi-walled carbon nanotubes (MWCNTs) and recovering H2 via pyrolysis-chemical vapor deposition (CVD) was explored. The research centered on investigating the impact of X-Mo/MgO catalysts (X = Co, Fe, Ni, and X: Mo: MgO mass ratio of 3:1:6) on the conversion of pyrolysis gases from the sludge at the CVD temperatures of 600–––800 °C. The results demonstrate that the catalyst efficiency is enhanced when CO2 is captured from pyrolysis gas prior to the CVD reactor (here, with a calcium-based sorbent). The three X-Mo/MgO catalysts showed the highest MWCNT and H2 yields at 700 °C compared to other temperatures. The Co-Mo/MgO catalyst exhibited the highest MWCNT production (2.9 wt% per feedstock) and H2 yield (140.7 mL per g of sludge) at 700 °C. The higher yield could be related to the smaller size of the metal particles of the spent catalyst. Furthermore, Co-Mo/MgO at 700 °C grown MWCNTs had more uniform diameter distribution and larger BET surface area. Notably, the produced MWCNTs were doped by N and S heteroatoms due to the presence of these elements in the sludge and the doping extent could be managed by controlling the CVD temperature, opening the pathway for customization of MWCNT properties. The highest doping levels were observed for MWCNTs grown on Fe-Mo/MgO at 600 °C (N − 3.4 at% and S – 2.3 at%) by XPS. According to these results, the pyrolysis-CVD process could be a feasible technique for the conversion of municipal sewage sludge into valuable biogenic MWCNTs and H2. The use of Co-Mo/MgO and Ni-Mo/MgO catalysts exhibited some advantages (e.g., high MWCNTs and H2 yields) compared to Fe-Mo/MgO catalysts. |
| first_indexed | 2025-03-09T09:48:36Z |
| format | Journal Article |
| id | ntu-10356/180771 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2025-03-09T09:48:36Z |
| publishDate | 2024 |
| record_format | dspace |
| spelling | ntu-10356/1807712024-10-23T05:15:59Z Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process Lu, Jintao Veksha, Andrei Lisak, Grzegorz School of Civil and Environmental Engineering Interdisciplinary Graduate School (IGS) Residues and Resource Reclamation Centre Nanyang Environment and Water Research Institute Engineering Chemical vapor deposition Municipal sewage sludge Utilization of municipal sewage sludge as a feedstock for synthesizing biogenic multi-walled carbon nanotubes (MWCNTs) and recovering H2 via pyrolysis-chemical vapor deposition (CVD) was explored. The research centered on investigating the impact of X-Mo/MgO catalysts (X = Co, Fe, Ni, and X: Mo: MgO mass ratio of 3:1:6) on the conversion of pyrolysis gases from the sludge at the CVD temperatures of 600–––800 °C. The results demonstrate that the catalyst efficiency is enhanced when CO2 is captured from pyrolysis gas prior to the CVD reactor (here, with a calcium-based sorbent). The three X-Mo/MgO catalysts showed the highest MWCNT and H2 yields at 700 °C compared to other temperatures. The Co-Mo/MgO catalyst exhibited the highest MWCNT production (2.9 wt% per feedstock) and H2 yield (140.7 mL per g of sludge) at 700 °C. The higher yield could be related to the smaller size of the metal particles of the spent catalyst. Furthermore, Co-Mo/MgO at 700 °C grown MWCNTs had more uniform diameter distribution and larger BET surface area. Notably, the produced MWCNTs were doped by N and S heteroatoms due to the presence of these elements in the sludge and the doping extent could be managed by controlling the CVD temperature, opening the pathway for customization of MWCNT properties. The highest doping levels were observed for MWCNTs grown on Fe-Mo/MgO at 600 °C (N − 3.4 at% and S – 2.3 at%) by XPS. According to these results, the pyrolysis-CVD process could be a feasible technique for the conversion of municipal sewage sludge into valuable biogenic MWCNTs and H2. The use of Co-Mo/MgO and Ni-Mo/MgO catalysts exhibited some advantages (e.g., high MWCNTs and H2 yields) compared to Fe-Mo/MgO catalysts. National Research Foundation (NRF) Public Utilities Board (PUB) This work was supported by the National Research Foundation, Singapore, and PUB, Singapore’s National Water Agency, under the RIE2025 Urban Solutions and Sustainability (USS) (Water) Center of Excellence (CoE) Program awarded to the Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological University, Singapore. 2024-10-23T05:15:59Z 2024-10-23T05:15:59Z 2024 Journal Article Lu, J., Veksha, A. & Lisak, G. (2024). Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process. Chemical Engineering Journal, 496, 153794-. https://dx.doi.org/10.1016/j.cej.2024.153794 1385-8947 https://hdl.handle.net/10356/180771 10.1016/j.cej.2024.153794 2-s2.0-85198288230 496 153794 en Chemical Engineering Journal © 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies. |
| spellingShingle | Engineering Chemical vapor deposition Municipal sewage sludge Lu, Jintao Veksha, Andrei Lisak, Grzegorz Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process |
| title | Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process |
| title_full | Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process |
| title_fullStr | Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process |
| title_full_unstemmed | Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process |
| title_short | Conversion of municipal sewage sludge into biogenic multi-walled carbon nanotubes and hydrogen using X-Mo/MgO (X = Co, Fe, Ni) catalysts through pyrolysis-chemical vapor deposition process |
| title_sort | conversion of municipal sewage sludge into biogenic multi walled carbon nanotubes and hydrogen using x mo mgo x co fe ni catalysts through pyrolysis chemical vapor deposition process |
| topic | Engineering Chemical vapor deposition Municipal sewage sludge |
| url | https://hdl.handle.net/10356/180771 |
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