An Integrated Approach to the Hydrothermal Carbonization of Sewage Sludge: Simulation, Modeling, and Life Cycle Assessment
Sewage sludge management at wastewater treatment plants is becoming a more and more challenging task. Here, an innovative integrated modeling approach is developed to investigate the optimization of a municipal wastewater treatment plant (MWWTP) by the inclusion of hydrothermal carbonization (HTC)....
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-05-01
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| Series: | ChemEngineering |
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| Online Access: | https://www.mdpi.com/2305-7084/7/3/44 |
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| author | Riccardo Bacci di Capaci Andrea Luca Tasca Riccardo Gori Sandra Vitolo Monica Puccini Gabriele Pannocchia |
| author_facet | Riccardo Bacci di Capaci Andrea Luca Tasca Riccardo Gori Sandra Vitolo Monica Puccini Gabriele Pannocchia |
| author_sort | Riccardo Bacci di Capaci |
| collection | DOAJ |
| description | Sewage sludge management at wastewater treatment plants is becoming a more and more challenging task. Here, an innovative integrated modeling approach is developed to investigate the optimization of a municipal wastewater treatment plant (MWWTP) by the inclusion of hydrothermal carbonization (HTC). To this aim, two alternative plant layouts have been considered: (i) a conventional activated sludge-based treatment plant, i.e., based on thickening, stabilization, conditioning, and dewatering; (ii) additional hydrothermal carbonization and integrated treatment of the spent liquor in the sludge line. An Italian MWWTP has been selected as a case study, and three different scenarios have been implemented in the process simulation software World Wide Engine for Simulation Training and Automation (WEST) by considering the effect of the different digestion times in the aerobic reactor. Then, according to the Design of Experiment (DoE) methodology applied both on simulated and experimental data, and by the use of a Python code, the desired models have been developed and compared. Finally, a Life Cycle Assessment (LCA) study has been carried out to estimate the impacts on human health, ecosystems, and resources. The integration of HTC corresponds to the generation of a valuable product (the hydrochar), whereas the conventional layout is associated with high disposal costs of the sewage sludge. According to LCA results, a sludge age of 40 days is recommended due to the lowest impacts estimated, both with and without a HTC section. This has been ascribed mainly to the electricity demand of the sludge line, which increases with the excess sludge flow rate, i.e., as the sludge age decreases. |
| first_indexed | 2024-03-11T02:39:11Z |
| format | Article |
| id | doaj.art-c927062fd94240f4b169261bd24fe8fa |
| institution | Directory Open Access Journal |
| issn | 2305-7084 |
| language | English |
| last_indexed | 2024-03-11T02:39:11Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | ChemEngineering |
| spelling | doaj.art-c927062fd94240f4b169261bd24fe8fa2023-11-18T09:45:00ZengMDPI AGChemEngineering2305-70842023-05-01734410.3390/chemengineering7030044An Integrated Approach to the Hydrothermal Carbonization of Sewage Sludge: Simulation, Modeling, and Life Cycle AssessmentRiccardo Bacci di Capaci0Andrea Luca Tasca1Riccardo Gori2Sandra Vitolo3Monica Puccini4Gabriele Pannocchia5Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, ItalyDepartment of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, ItalyDepartment of Civil and Environmental Engineering, University of Firenze, 50139 Firenze, ItalyDepartment of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, ItalyDepartment of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, ItalyDepartment of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, ItalySewage sludge management at wastewater treatment plants is becoming a more and more challenging task. Here, an innovative integrated modeling approach is developed to investigate the optimization of a municipal wastewater treatment plant (MWWTP) by the inclusion of hydrothermal carbonization (HTC). To this aim, two alternative plant layouts have been considered: (i) a conventional activated sludge-based treatment plant, i.e., based on thickening, stabilization, conditioning, and dewatering; (ii) additional hydrothermal carbonization and integrated treatment of the spent liquor in the sludge line. An Italian MWWTP has been selected as a case study, and three different scenarios have been implemented in the process simulation software World Wide Engine for Simulation Training and Automation (WEST) by considering the effect of the different digestion times in the aerobic reactor. Then, according to the Design of Experiment (DoE) methodology applied both on simulated and experimental data, and by the use of a Python code, the desired models have been developed and compared. Finally, a Life Cycle Assessment (LCA) study has been carried out to estimate the impacts on human health, ecosystems, and resources. The integration of HTC corresponds to the generation of a valuable product (the hydrochar), whereas the conventional layout is associated with high disposal costs of the sewage sludge. According to LCA results, a sludge age of 40 days is recommended due to the lowest impacts estimated, both with and without a HTC section. This has been ascribed mainly to the electricity demand of the sludge line, which increases with the excess sludge flow rate, i.e., as the sludge age decreases.https://www.mdpi.com/2305-7084/7/3/44design of experimentshydrothermal carbonizationintegrated modelingmunicipal wastewater treatmentsewage sludge |
| spellingShingle | Riccardo Bacci di Capaci Andrea Luca Tasca Riccardo Gori Sandra Vitolo Monica Puccini Gabriele Pannocchia An Integrated Approach to the Hydrothermal Carbonization of Sewage Sludge: Simulation, Modeling, and Life Cycle Assessment ChemEngineering design of experiments hydrothermal carbonization integrated modeling municipal wastewater treatment sewage sludge |
| title | An Integrated Approach to the Hydrothermal Carbonization of Sewage Sludge: Simulation, Modeling, and Life Cycle Assessment |
| title_full | An Integrated Approach to the Hydrothermal Carbonization of Sewage Sludge: Simulation, Modeling, and Life Cycle Assessment |
| title_fullStr | An Integrated Approach to the Hydrothermal Carbonization of Sewage Sludge: Simulation, Modeling, and Life Cycle Assessment |
| title_full_unstemmed | An Integrated Approach to the Hydrothermal Carbonization of Sewage Sludge: Simulation, Modeling, and Life Cycle Assessment |
| title_short | An Integrated Approach to the Hydrothermal Carbonization of Sewage Sludge: Simulation, Modeling, and Life Cycle Assessment |
| title_sort | integrated approach to the hydrothermal carbonization of sewage sludge simulation modeling and life cycle assessment |
| topic | design of experiments hydrothermal carbonization integrated modeling municipal wastewater treatment sewage sludge |
| url | https://www.mdpi.com/2305-7084/7/3/44 |
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