Exergy analysis for enhanced performance of integrated batch reverse osmosis – Forward osmosis system for brackish water treatment

• Published in: Desalination Vol. 580; p. 117548
• Main Authors: Patel, Dhaval, Mudgal, Anurag, Patel, Vivek, Patel, Jatin, Park, Kiho, Davies, Philp, Dhakal, Nirajan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2024
• Subjects: Batch reverse osmosis; Economic; Forward osmosis; Fresh water cost; Specific energy consumption; Specific solution cost; Specific solution cost; Specific energy consumption; Economic; Forward osmosis; Batch reverse osmosis; Fresh water cost
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2024.117548

Concept of integrated brackish water batch reverse osmosis – forward osmosis (BRO – FO) is relatively new in the field of desalination. Recovery of the reverse osmosis (RO) system can be elevated using the free piston BRO concept, and the specific energy consumption (SEC) can be reduced. This study focuses on exergy, advanced exergy, and parametric analysis of the integrated BRO - FO system. The conventional exergy analysis suggests that the largest rate of exergy destruction is associated with the system's RO membrane module and pump, with values of 6.51 and 87.06 %, respectively. However, advanced exergy analysis shows that this rate can be reduced by 3.53 % and 62.89 %, respectively. Endogenous exergy destruction of pumps and membranes is higher compared to exogenous exergy destruction. These results are utilised to determine the system's optimal performance using parametric analysis. Sensitivity analysis was utilised to obtain an optimum recovery for system design, fresh water cost (FWC), and specific solution cost (SSC). The BRO can achieve >80 % recovery with 0.43 kWh/m3 SEC, and FO technology helps to attain minimal/zero waste discharge. Thus, a FWC of 0.50 $/m3 and a SWC of 0.44 $/m3 can be achieved. [Display omitted] •Quantified exergy destruction for optimization of an integrated BRO - FO system•Dual approach: Desalination and waste reuse with integrated BRO - FO system•Identified optimum recovery of BRO system for integrated operation•Determined minimum FWC and SSC at optimal recovery and specific energy consumption