Abstract This research provides an analysis of energy efficiency and cost evaluation for three types of two-staged reverse osmosis (RO) and hollow fibre pressure retarded osmosis (PRO) hybrid process; 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). Firstly, models are built from first principles assuming multi-staged RO-PX (pressure exchanger) has equal stage recovery considering the effect of booster pumps and pressure drop in the RO system. Then, all simulations are implemented by MATLAB 2018b, and energy efficiencies are assessed based on the normalised specific energy consumption, NSEC. All hybrid processes are found to have higher total water prices (TWP) when the electricity price is 0.10 US$/kWh; however, they show certain advantages under different electricity prices when wastewater pretreatment and delivery of wastewater are neglected. 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. The requirement of wastewater pretreatment and wastewater pump and the further development of PRO membranes are the keys to practical operations.

中文翻译：

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两级反渗透和压力延迟渗透海水淡化工艺的成本评估

摘要 本研究对三类两级反渗透（RO）和中空纤维压力延迟渗透（PRO）混合工艺进行了能源效率和成本评价分析；一种没有直接进料流（混合动力 A），一种有直接进料流（混合动力 B），一种有直接进料流和涡轮机（混合动力 C）。首先，模型是根据第一性原理建立的，假设多级 RO-PX（压力交换器）具有等级回收，考虑到升压泵的影响和 RO 系统中的压降。然后，所有仿真均由 MATLAB 2018b 实现，并根据归一化比能耗 NSEC 评估能效。当电价为 0.10 美元/kWh 时，所有混合过程都具有更高的总水价 (TWP)；然而，在忽略废水预处理和废水输送的情况下，它们在不同的电价下表现出一定的优势。即使在水价低、电价高（由于对电价不敏感）的国家，混合 C 也特别有吸引力。废水预处理和废水泵的要求以及PRO膜的进一步发展是实际操作的关键。