Recently, reverse osmosis (RO) is the most common process for seawater desalination. A common problem in both RO and thermal processes is the high energy requirements for seawater desalination. The one energy saving method when utilizing the osmotic power is utilizing pressure retarded osmosis (PRO) process. The PRO process can be used to operate hydro turbines for electrical power production or can be used directly to supplement the energy required for RO desalination system. This study was carried out to evaluate the performance of both single-stage PRO process and two-stage PRO process using RO concentrate for a draw solution and RO permeate for a feed solution. The major results, were found that increase of the draw and feed solution flowrate lead to increase of the production of power density and water permeate. Also, comparison between CDCF and CDDF configuration showed that the CDDF was better than CDCF for stable operation of PRO process. In addition, power density of two-stage PRO was lower than the one of single-stage. However, net power of two-stage PRO was higher than the one of single-stage PRO.

1. 서 론
 2. 압력지연삼투(pressure retarded osmosis: PRO)
  2.1 수투과량과 전력밀도
  2.2 농도분극(concentration polarization) 현상
 3. 실험 재료 및 방법
  3.1 실험 재료
  3.2 PRO 공정
  3.3 막 모듈 배치 및 유입원수 흐름에 따른 성능 분석
 4. 결과 및 고찰
  4.1 Single-stage PRO process
  4.2 Two-stage PRO process (CDCF vs. CDDF)
  4.3 Single-stage와 two-stage PRO process의 비교
 5. 결 론
 References

• 고길현(부경대학교 환경공학과) | Gilhyun Go (Department of Environmental Engineering, Pukyong National University)
• 김동현(부경대학교 환경공학과) | Donghyun Kim (Department of Environmental Engineering, Pukyong National University)
• 박태신(GS 건설) | Taeshin Park (GS E&C)
• 강임석(부경대학교 환경공학과) | Limseok Kang (Department of Environmental Engineering, Pukyong National University)