Energy efficiency of batch and semi-batch (CCRO) reverse osmosis desalination

WATER RESEARCH

卷:106

Article

Warsinger, David M.¹  Tow, Emily W.¹  Nayar, Kishor G.¹  Maswadeh, Laith A.²  Lienhard, John H.¹ 

[1] MIT, Dept Mech Engn, Rohsenow Kendall Heat Transfer Lab, 77 Massachusetts Ave, Cambridge, MA 02139 USA

[2] Stanford Univ, Dept Management Sci & Engn, 450 Serra Mall, Stanford, CA 94305 USA

关键词: Desalination;    Batch reverse osmosis;    Energy efficiency;    Pressure recovery;    Reverse osmosis;    Closed-circuit reverse osmosis;   

DOI  :  10.1016/j.watres.2016.09.029

来源: Elsevier

【 摘 要 】

As reverse osmosis (RO) desalination capacity increases worldwide, the need to reduce its specific energy consumption becomes more urgent. In addition to the incremental changes attainable with improved components such as membranes and pumps, more significant reduction of energy consumption can be achieved through time-varying RO processes including semi-batch processes such as closed-circuit reverse osmosis (CCRO) and fully-batch processes that have not yet been commercialized or modelled in detail. In this study, numerical models of the energy consumption of batch RO (BRO), CCRO, and the standard continuous RO process are detailed. Two new energy-efficient configurations of batch RO are analyzed. Batch systems use significantly less energy than continuous RO over a wide range of recovery ratios and source water salinities. Relative to continuous RO, models predict that CCRO and batch RO demonstrate up to 37% and 64% energy savings, respectively, for brackish water desalination at high water recovery. For batch RO and CCRO, the primary reductions in energy use stem from atmospheric pressure brine discharge and reduced streamwise variation in driving pressure. Fully-batch systems further reduce energy consumption by not mixing streams of different concentrations, which CCRO does. These results demonstrate that time-varying processes can significantly raise RO energy efficiency. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

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