https://scholars.lib.ntu.edu.tw/handle/123456789/633492
標題: | Anaerobic swine digestate valorization via energy-efficient electrodialysis for nutrient recovery and water reclamation | 作者: | Wei, Chao Yu SHU-YUAN PAN Lin, Yu I. Cao, Thanh Ngoc Dan |
關鍵字: | Cost benefit analysis | Energy consumption | Kinetics | Productivity | Response surface model | 公開日期: | 1-十月-2022 | 卷: | 224 | 來源出版物: | Water Research | 摘要: | The development of cost-effective and energy-efficient technologies to recover nutrients from digestate is important. Anaerobic digestate can be concentrated into bio-nutrient products through an electrodialysis (ED) process in an energy-efficient manner. Despite recent advances, the operation modes of ED for nutrient recovery from swine digestate are yet to be systematically evaluated from the perspective of energy-water efficiencies, and the determination of optimal operations in ED units is still ambiguous. In this study, two different operating modes of electrodialysis, i.e., constant voltage and constant current, are designed to evaluate the energy efficiency and effectiveness of nutrient recovery from anaerobic swine digestate. The ion removal ratio and current efficiency of the different modes and their associated electromigration performance (e.g., rate constants) are evaluated. The results indicate that the maximum removal efficiency (in terms of electrical conductivity) is 92.8% at a cell voltage of 2.4 V/cell using the constant voltage operation. The current efficiencies of NH4+ (43‒65%) are higher than that of other ions, such as K+ (12‒19%), Cl- (4‒7%), and PO43- (0.1‒1.5%). For nitrogen recovery, the required energy consumption was about 0.24‒15.2 kWh/kg-N (0.86‒54.7 kJ/g-N), corresponding to a removal ratio of ammonium from 70.8% to 99.1%. Based on the experimental data, the optimal operating conditions are identified using response surface models by considering process energy consumption and productivity to deliver energy-efficient nutrient separation. One candidate of the ideal conditions to achieve the total ion removal of ∼93% should be operated at a constant cell voltage of 1.15 V, corresponding to a productivity of 5.24 gal/hr/m2 at an energy consumption of 0.44 kWh/m3. Last, a conceptual design of cascading separation processes is proposed for digestate valorization as biofertilizers, nutrients, organic acids, and reclaimed water. A preliminary benefit-cost evaluation is then performed to evaluate the engineering and economic performance of the developed process for nutrient recovery from swine digestate. This article provides insight into practical large-scale applications of digestate valorization through energy-efficient separation, thereby realizing a circular economy system and a decarbonizing supply chain of bio-nutrients. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85137618081&doi=10.1016%2fj.watres.2022.119066&partnerID=40&md5=391c8179ff0241c3a7f94091fb21918a https://scholars.lib.ntu.edu.tw/handle/123456789/633492 |
ISSN: | 00431354 | DOI: | 10.1016/j.watres.2022.119066 |
顯示於: | 生物環境系統工程學系 |
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