請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/66832
標題: | 多階段逆滲透及壓力延遲滲透海水淡化程序之能耗分析與成本評估 Energy Analysis and Cost Evaluation for Multi-Staged Reverse Osmosis and Pressure Retarded Osmosis Desalination Process |
作者: | Naomi Sawaki 澤木直美 |
指導教授: | 陳誠亮(Cheng-Liang Chen) |
關鍵字: | 多階段逆滲透,壓力延遲滲透,壓力交換器,標準化比能耗,總水價, Multi-staged reverse osmosis (RO),Pressure-retarded osmosis (PRO),Pressure exchanger (PX),normalised specific energy consumption (NSEC),Total water price (TWP), |
出版年 : | 2020 |
學位: | 碩士 |
摘要: | 逆滲透(RO)已廣泛應用在海水淡化技術來生產飲用水。儘管在過去幾十年中開發了壓力交換器(PXs)等能量回收設備(ERD),並且膜技術得到了顯著改進,但RO仍然是生產飲用水最耗能的替代方法。
本文提供為多階段逆滲透和壓力延遲滲透(PRO)混合程序之能耗分析與成本評估。首先,根據第一原理建立單段、兩段、多階段RO-PX模型。於特定假設之下,發現多階段RO-PX的最佳段比率為x=1,並且兩段程序顯示出一定的能源效率改善。其次,將PRO模型添加到多階段RO-PX模型中,討論了三種多階段混合過程;一個不帶直接給水流量(混合程序A),一個帶直接給水流量(混合程序B),一個帶直接給水流量與渦輪機(混合程序C)。接著由MATLAB 2018b進行所有模擬,並基於標準化比能耗(NSEC)評估效能。 添加PX在NSECmin上有重大改進。單段RO-PX的NSECmin=1.88,與無PX的過程相比,此值小59 %。當忽略廢水泵時,與RO-PX程序相比,添加PRO還可以降低NSECmin。 RO階段的增加也有助於降低能耗;但是,它的影響僅在最初的幾階段才明顯,最終達到極限。與單段過程相比,兩段操作顯示NSECmin有一定的改進。因此,基於兩段RO對混合程序進行成本評估,並將其與兩段RO-PX進行比較。當電價設置為0.10 US$/kWh時,所有混合程序之總水價(TWP)都會變高。然而,當廢水預處理被忽略時,混合程序在不同的電價下顯示出一定的優勢。在低電價地區,RO-PX相較於有添加PRO之混合程序更具競爭力,而在高電價地區,混合程序A與混合程序C則較具競爭力。其中混合程序C對電價不敏感,因此在電價高且水價低的地區也具競爭力。廢水預處理、廢水泵以及PRO膜之發展是實際操作一步開發的關鍵。 Reverse osmosis (RO) has been widely applied as major seawater desalination technology to produce potable water. Despite the development of energy recovery devices (ERDs) such as pressure exchangers (PXs) and dramatic improvements in membrane technology over the last few decades, RO remains to be the most energy intensive alternative to produce potable water. This thesis provides analysis of energy efficiency and cost evaluation for multi-staged RO and pressure retarded osmosis (PRO) hybrid process. Firstly, single-, two- and multi-staged RO-PX models are built from first principles. Multi-staged RO-PX are found to have an optimum stage ratio of x = 1 under specific assumptions, and two-staged process shows certain improvement on energy efficiency. Secondly, PRO model is added to multi-staged RO-PX model and three multi-staged hybrid processes are discussed; one without direct feed flow (Hybrid A), one with direct feed flow (Hybrid B) and one with direct feed flow and a turbine (Hybrid C). Then, all simulations are conducted by MATLAB 2018b, and energy efficiencies are assessed based on normalised specific energy consumption, NSEC. Addition of PXs has significant improvements on NSECmin. Single-staged RO-PX has NSECmin = 1.88, and this value is 59 % smaller compared to the process without PX. Addition of PRO also lowers NSECmin compared to RO-PX process when wastewater pump is neglected. Increasing the number of RO stages also contributes to reduction in energy consumption; however, its effect is distinct only for first few stages, and it eventually reaches a limit. Two-staged operation shows a certain improvement on NSECmin compared with single-staged process. Therefore, cost evaluations for hybrid processes are conducted based on two-staged RO and they are compared with two-staged RO-PX. All hybrid process have higher total water price (TWC) when electricity price is set to 0.10 US$/kWh. However, hybrid processes show certain advantages under different electricity prices when wastewater pretreatment is wastewater pump are neglected. RO-PX is found to be the most competitive process in regions with low electricity prices, where Hybrid A and Hybrid C are more competitive in regions with high electricity prices. Hybrid C is especially attractive even in countries where water prices are low and electricity prices are high due to its insensitiveness to electricity prices. Requirement of wastewater pretreatment and wastewater pump are the keys to practical operations as well as further development of PRO membranes. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/66832 |
DOI: | 10.6342/NTU202000183 |
全文授權: | 有償授權 |
顯示於系所單位: | 化學工程學系 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-109-1.pdf 目前未授權公開取用 | 4.89 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。