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© Copyright National University of Singapore. All Rights Reserved.
Optimizing mixing time to lower the energy consumption of an anaerobic digestion waste-to-energy system for food waste management
Jingxin ZHANG / Yen Wah TONGChina-UK Low Carbon College / Dept of Chemical & Biomolecular EngShanghai Jiaotong University / National University of [email protected] / [email protected]
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Food Waste
Anaerobic digestion
Digestate
Fertilizer
Wastewater
Electricity
Cooling
Waste Heat
Recovery
Chiller
Building
Anaerobic Digestion
Collection & Sorting
AnamialManure
HorticulturalWaste
Agricultural Waste
Biogas
Engine Generator
Dry wastes
Incineration & Gasification
ANAEROBIC DIGESTION WTE
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Waste sorting
Sensitive
Energy Intensive
Low energy recovery
High sorting efficiency
High treatment capacity
Low energy consumption
Efficient energy recovery
Chellenges Demands
Optimizing mixing in Anaerobic digester ?
CHALLENGES AND DEMANDS FOR FOOD WASTE TREATMENT
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OPTIMIZATION OF MIXING TIME IN AD
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FOOD WASTE
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Optimum Mixing Time – 2 mins/hour
COMPUTATIONAL FLUID DYNAMICS MODELING
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Semi-continuous mixing mode is
preferred !
STATISTICAL ANALYSIS OF PROCESS PARAMETERS
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Food Waste
Biogas
Electricity and heat
Anaerobic Digestion System
Combined Heat and Power System
Recovery
Net energy output
FOOD WASTE AD SYSTEM
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CHP - Combined heat and power unit
ENERGY FLOW CHART
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Net energy output is achieved in semi-continuous mixing mode
ENERGY PERFORMANCE
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Computational Fluid Dynamics (CFD) modelling for mixing
Model + Experiments
Semi-continuous mixing strategy
Different Scales of Engine Generator systems
REDUCING ENERGY CONSUMPTION
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NUS Frontier Phase Canteen
APPLICATIONS IN SINGAPORE
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© Copyright National University of Singapore. All Rights Reserved.
CONCLUSIONS
• Energy consumption for AD systems can be optimized
• Reduction through mixing time and process parameters
• Combination of CFD modeling and experimental validation in pilot-scale systems
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ACKNOWLEDGEMENTS
• Collaborators:• (SJTU) PENG Yinghong, DAI Yanjun, GE
Tianshu, WANG Ruzhu• (NUS) WANG Chi-Hwa, LOH Kai Chee,
WANG Xiaonan, Adam NG, Michel CARDIN• Group members: Dr Zhang Jingxin, Dr Li
Wangliang, Dr Ingo Wolf, Dr Siddharth Jain, Dr Yan Weicheng, Dr Tong Huanhuan, Dr Lim Jun Wei, Dr Jonathan Lee, Dr Tian Hailin, Mr Mao Liwei, Ms Zhang Jingru, Ms Guo Yalei, Mr Zhang Le, Mr Lim Ee Yang
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THANK YOU!
This programme is funded by the National Research Foundation, Prime Minister’s Office, Singapore under its Campus for Research Excellence and Technological Enterprise programme.