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A novel solar‐assisted cascade Rankine cycle‐driven reverse osmosis (RO) system is proposed and evaluated using conventional and advanced exergy analysis. The system comprises a solar collector as a heat input, steam Rankine cycle (SRC), and organic Rankine cycle (ORC) to generate turbine work and RO units for brackish water treatment. Water and R1233zd(E) are used as the working fluid in the SRC and ORC, respectively. The RO system is proposed to produce 1 m3 h−1 of permeate water from each RO unit. Conventional exergy analysis shows that the solar collector exhibits the highest exergy destruction of 0.798 kW, followed by the RO unit. However, advanced exergy analysis reveals that only 16.16% of the avoidable exergy in solar collectors can be reduced due to technical constraints. Advanced exergy analysis identified that endogenous avoidable exergy destruction contributes 24% of overall exergy destruction, which can be reduced by optimizing operating parameters and making technical improvements. The RO unit has a higher exogenous avoidable exergy, potentially suggesting improvements in other system component parameters. The advanced exergy analysis also prioritized the components for improving system performance in a sequence of RO high‐pressure pumps, RO modules, solar collector, ORC condenser, evaporative condenser, ORC expander, and SRC turbine. [ABSTRACT FROM AUTHOR]

A thermodynamic optimization analysis of single effect LiBr-H 2 O vapour absorption cooling system of 1 TR capacity is conducted based on first and second laws. Mathematical models derived from thermodynamics theory, are employed in engineering equation solver to perform the calculations. Minimum generator temperature required to operate the system that is cut off temperature has been evaluated. Realistic comparison of thermodynamic first and second law approaches have also been evaluated. It is found that cut off temperature of system decreases with evaporator temperature and increases with condenser and absorber temperature. It is observed that optimum generator temperature decreases with evaporator temperature and increases with condenser temperature. Hence it is feasible to find out optimum generator temperature for various condenser-evaporator temperatures. Corresponding contour plots have also been depicted for optimum generator temperature. Adoption of optimized exergy approach is advisable owing to fact that exergy destruction rate is more sensitive compared to COP of system. [ABSTRACT FROM AUTHOR]

A thermodynamic analysis of single effect LiCl-H 2 O vapour absorption cooling system of 1 TR capacity is conducted based on first and second laws. Mathematical models derived from thermodynamics theory, are employed in engineering equation solver to perform the calculations. It is found that maximum exergy destruction in system occurs in the absorber and generator while the pump and the expansion valve have the lowest. A performance comparison between LiCl-H 2 O and LiBr-H 2 O absorption system is also evaluated under identical operating conditions. It is found that LiCl-H 2 O working pair performs thermodynamically better compared to LiBr-H 2 O in vapour absorption cooling system. [ABSTRACT FROM AUTHOR]

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 [ABSTRACT FROM AUTHOR]

A novel cascade Rankine cycle is proposed for treating brackish groundwater using a reverse osmosis system. The cascade RO system is arranged in a loop with a steam Rankine cycle (SRC) at the top and an organic Rankine cycle (ORC) at the bottom to provide high recovery, electricity-free, and scalable options. The system comprises a solar Scheffler dish for heat input, steam turbine and expander for work output, evaporative condenser and ORC condenser for heat rejection, SRC pump, ORC pump and RO high-pressure pump for work input devices, and RO module for water desalination. This study evaluated the thermodynamic design of the system along with energy, exergy, and economic analyses performed by considering eight working fluids such as R245fa, HFO1336mzz(Z), R1225ye(Z), R1224yd(Z), R1233zd(E), R1243zf, R1234yf, and R1234ze(E). The highest overall efficiency was found 14.08% with R1234yf, and the highest RO permeate flow rate was found with R245fa, HFO1336mzz(Z), and R1233zd(E), which require the lowest mass flow rate of ORC working fluid. The highest exergy destruction was found in the solar collector and RO unit. The treated water cost is estimated to be 0.89–0.924 $/m3 of permeate water. [Display omitted] • The thermodynamic design of solar-powered SRC, ORC, and RO systems is investigated. • Energy, exergy, and economic analyses are performed with eco-friendly working fluids. • The treated water cost of selected ORC working fluids is examined. [ABSTRACT FROM AUTHOR]

Energy, exergy, economic and environmental analysis is applied to a novel FO system. The system is designed to achieve minimal/zero liquid discharge with low specific energy consumption. Up to 43 % recovery is obtained with desired output in terms of salinity of diluted draw solution and concentrated feed solution. The specific energy required to produce diluted draw and concentrated feed solutions for the proposed application is as low as 0.0285 kWh/m3. In this study, DS-Lumen/AL-DS mode shows specific energy savings of 49.5 % in performed cases compared to FS-Lumen/AL-FS mode using a less flow rate of draw solution. The process design is done to reach the appropriate salinity level at the system outlet. The feed solution connection is in the series between membranes, which helps to dilute the draw solution, while the draw solution connection is in parallel between membranes to achieve desired salinity level at the outlet. The influence of the feed and draw solution temperature and flow rate on the membrane performance is observed. Capital and operating costs of the membrane and other costs, such as tank and chemical solution costs, are significant contributors to the total cost. The specific solution (total output of FO system) cost is estimated at 0.23 $/m3. Environmental analysis suggests that the deployment of solar energy as an energy source of the system reduces 93.06 % of CO 2 emissions compared to fossil fuel (coal). [Display omitted] • Energy consumption in a standalone FO system is evaluated according to the mode of operation. • Flow arrangement is used to achieve the desired output concentration. • Exergy analysis is used to identify potential improvements in the system. • Renewable energy options are identified to meet the energy requirements of FO with minimum CO 2 emission. • Wind, nuclear, and hydro energy sources show a minimum CO 2 emission rate for FO operation. • Component contributions towards the CAPEX and OPEX of the FO system are identified. • FO yield irrigates salt-tolerant crops to achieve MLD/ZLD and zero waste discharge. [ABSTRACT FROM AUTHOR]