Analysis of energy consumption and costs in hybrid SWFO, crystallization and SWRO process
- 주제(키워드) desalination , forward osmosis , reverse osmosis , crystallization
- 발행기관 고려대학교 대학원
- 지도교수 양대륙
- 발행년도 2013
- 학위수여년월 2013. 8
- 학위구분 석사
- 학과 일반대학원 화공생명공학과
- 원문페이지 156 p
- 실제URI http://www.dcollection.net/handler/korea/000000046192
- 본문언어 영어
- 제출원본 000045764451
초록/요약
Membrane based seawater desalination and wastewater reuse are widely considered as promising solutions to augment water supply and alleviate water scarcity. At present, reverse osmosis (RO) is one of the most effective and robust technologies for seawater desalination and wastewater reuse. Nevertheless, RO process generally requires high applied pressure which leads to high energy requirement. In pursuit of energy reduction, a hybrid SWFO, Crystallization and SWRO process as an alternative existing desalination membrane process is suggested. This hybrid system was designed to conduct FO, RO and Crystallization all together. When seawater and concentrated draw solution are pumped to FO process at around room temperature, the water molecules of seawater side permeate through a semi-permeable membrane to the other side of the membrane by their chemical potential gradient. Then, the diluted draw solution flows to the crystallization process at lower temperature, so draw solutes are crystallized from draw solution and precipitated. The draw solution from crystallizer with the lowered concentration is fed into RO process for water production. The diluted RO feed requires much less energy than SWRO. Also, the draw solute crystal and RO concentrate are mixed and recycled as draw solution for FO process. During this process, a refrigerator is used for cooling the draw solution from FO process and the heat from the refrigerator is used to heat the draw solution for RO process for energy saving. In the study, the simulation through mathematical model which consist of mass and energy balance equation and the experiments for each process like FO, RO, crystallization process, are carried out to estimate the required energy and analysis costs of the hybrid SWFO, Crystalization and SWRO process. As a result, the energy consumptions and overall costs of the hybrid process using the selected draw solutes are lower than the typical RO process.
more목차
1. INTRODUCTION - 1 -
2. THEORY - 11 -
2.1 Desalination Technology - 11 -
2.2 Thermal desalination - 11 -
2.3 Membrane desalination - 14 -
2.3.1 Membrane process (Osmotic process) - 14 -
2.3.2 Concentration polarization (CP) - 17 -
2.4 Reverse osmosis (RO) - 23 -
2.4.1 Advantages and disadvantages of RO Process - 23 -
2.4.2 Required Energy for SWRO Process - 24 -
2.4.3 Pretreatment process in SWRO process - 26 -
2.5 Forward osmosis (FO) - 34 -
2.5.1 Advantages of FO Process - 34 -
2.5.2 PRO Process - 34 -
2.5.3 Draw solution - 35 -
2.5.4 Modeling of FO process - 36 -
2.6 Hybrid SWFO, Crystallization and SWRO process - 43 -
3. MATERIALS AND METHODS - 47 -
3.1 Chemicals - 47 -
3.2 Membrane materials - 47 -
3.3 Procedure of crystallization experiment - 51 -
3.4 Procedure of forward osmosis (FO) experiment - 52 -
3.5 Procedure of reverse osmosis (RO) experiment - 53 -
4. EXPERIMENTAL AND SIMULATION RESULTS - 59 -
4.1 Selection of draw solute for hybrid process - 59 -
4.1.1 Essential factors of draw solute - 59 -
4.1.2 Screening of draw solutes - 61 -
4.2 Results of the crystallization process - 65 -
4.2.1 Results of solubility experiment - 65 -
4.2.2 Predicted osmotic pressure of draw solutions - 73 -
4.3 Results of forward osmosis process - 75 -
4.3.1 Experimental Results of forward osmosis(FO) - 75 -
4.3.2 Simulation results of forward osmosis(FO) process - 79 -
4.4 Results of reverse osmosis process - 93 -
4.4.1 Experimental results of reverse osmosis (RO) - 93 -
4.4.2 Simulation results of reverse osmosis(RO) process - 94 -
4.5 Energy consumption - 100 -
4.5.1Modeling of energy in hybrid process - 100 -
4.5.2 Simulation results of energy consumption - 108 -
4.6 Cost analysis for the hybrid process - 116 -
4.6.1Purpose of cost analysis - 116 -
4.6.2 Procedure of cost analysis for hybrid process - 118 -
4.6.3 Modeling of costs in hybrid process - 122 -
4.6.4 Cost for typical RO process - 126 -
4.6.5 Cost for the hybrid process - 128 -
5. CONCLUSIONS. - 137 -
6. REFERENCE - 139 -
