Evaluation of the Specific Energy Consumption of Sea Water Reverse Osmosis Integrated with Membrane Distillation and Pressure–Retarded Osmosis Processes with Theoretical Models

Abstract

In this study, theoretical models for specific energy consumption (SEC) were established for water recovery in different integrated processes, such as RO-PRO, RO-MD and RO-MD-PRO. Our models can evaluate SEC under different water recovery conditions and for various proportions of supplied waste heat. Simulation results showed that SEC in RO increases with the water recovery rate when the rate is greater than 30%. For the RO-PRO process, the SEC also increases with the water recovery rate when the rate is higher than 38%, but an opposite trend can be observed at lower water recovery rates. If sufficient waste heat is available as the heat source for MD, the integration of MD with the RO or RO-PRO process can significantly reduce SEC. If the total water recovery rate is 50% and MD accounts for 10% of the recovery when sufficient waste heat is available, the SEC values of RO, RO-PRO, RO-MD and RO-MD-PRO are found to be 2.28, 1.47, 1.75 and 0.67 kWh/m3, respectively. These critical analyses provide a road map for the future development of process integration for desalination.

Carbon Emission Calculations and Reductions in Membrane Water Treatment: A Review

“…11 Second, it has been shown that the application of membrane technology can reduce the energy demand for reclaimed water production and maintain high water recovery rates. 23 Finally, waste membrane modules can be reused in whole or in part. The whole or partial structure and materials of high-pressure waste membranes are used in low-pressure filtration systems, which show similar performance to new low-pressure membranes.…”

“…First, resource recovery from the water treatment process reduces the secondary pollution of the environment, especially methane recovery, which reduces greenhouse gas emissions and enables the secondary use of fuel. , The residual sludge that will be processed through the process can be used as fertilizer, which avoids GHG emissions from the sludge disposal process and also achieves the reuse of nutrients . Second, it has been shown that the application of membrane technology can reduce the energy demand for reclaimed water production and maintain high water recovery rates . Finally, waste membrane modules can be reused in whole or in part.…”