Green power generation from the Tigris River using pressure retarded osmosis process

Abstract

Sustainability including renewable energy and green power, is one of the important feature in recent years due to environmental constraints and the emission of CO2 from fossil fuel. Pressure retarded osmosis (PRO) process is considered one of the effective technology for power generation. This study assessed the application of pressure retarded osmosis to produce power from Tigris River water in Baghdad City, Iraq. Spiral wound TFC membrane was tested in the PRO process with different variables. The effect of different types of draw solutions (MgCl2, NaCl, Sodium Formate, KCl, Sodium Acetate), applied pressure (0 – 7 bar), and draw solution concentration (0.08 and 0.4 M) were tested in this work. The flux, recovery, and power density for the five draw solution in the order MgCl2 >NaCl>sodium formate>KCl>sodium acetate, while the reverse solute flux in the order MgCl2 <sodium acetate<KCl<sodium formate<NaCl. Experimentally the membrane pure water permeability (A) was found to be 4.87 L/m2.h.bar. The result revealed that the reverse solute flux and the solute permeability coefficient for MgCl2 was 0.55 g/m2.h and 8.78 × 10−8 m/s. The flux, recovery, and power density for MgCl2 with a concentration of 0.4 M and applied pressure of 7 bar was 1.69 LMH, 19 %, and 0.33 W/m2, respectively.