A pressure-enhanced osmosis (PEO) system for maximizing generation of osmotic energy, comprising
- a main PEO forward osmosis module, the main PEO forward osmosis module further comprising a pressurized vessel with a draw solution compartment, a feed solution compartment, and semipermeable membrane being positioned between the draw solution compartment and the feed solution compartment, wherein the draw solution compartment of the main PEO forward osmosis module is being supplied with a draw solution input flow with a dilution factor β in a range of 0.85 to 0.95 for an input draw solution flux Q2, β=Q2/(Q1+Q2), Q1 is a permeate flux, and an input hydraulic pressure p2=½αβΔπo, wherein α is a membrane efficiency factor representing a percentage of pressure remaining across the semipermeable membrane, and Δπo is a theoretical maximum osmotic pressure differential of the main PEO forward osmosis module,
- a plurality of tubular membrane modules, the tubular membrane modules further comprising a plurality of porous casing to house the semipermeable membrane in the tubular membrane modules, respectively, for flowing a feed solution inside tubes of the tubular membrane modules and creating the permeate flux Q1,
- a plurality of mixers, the plurality of mixers further comprising a plurality of combined propeller and turbine blades for homogenizing the input draw solution flux Q2 inside the pressurized vessel and reducing effects of external concentration polarization of the tubular membrane modules,
- a stainless-steel housing for maintaining constant pressure p2 created by the input draw solution at the selected β and Q2 values and for housing the plurality of the tubular membrane forward osmosis modules and the mixers,
- a draw solution inflow control valve and a pump for controlling the input draw solution flux Q2,
- a draw solution inflow and outflow check valves for preventing backflow,
- a pressure gauge and control valve and control pump thereof for adjusting vessel pressure,
- a pressure relief valve for preventing vessel pressure beyond the level of p2 to assist in maintaining steady-state continuous flow condition of the pressurized PEO module, and
- an energy exchange and fluid recovery device to supply the input hydraulic pressure p2, and the input draw solution flux Q2, for the generation of the power amount of p2(Q1+Q2) in the main PEO forward osmosis module, the energy exchange and fluid recover device further comprising
- a pressure exchanger, the pressure exchanger further comprising a low-pressure draw solution input flow port for inputting a low-pressure fluid, a high-pressure draw solution output flow port for forming the draw solution with required hydraulic pressure p2 and flux Q2 a high-pressure high-concentration fluid input port for bringing in higher energy content fluid for the pressure exchanger,
- a venturi injector unit comprising a connection pipe to the pressure exchanger for bringing back low-pressure high-concentration fluid, the venturi injector unit further comprising a low-pressure fluid input port for inputting the low-pressure high-concentration fluid from the pressure exchanger, a high-pressure high-concentration fluid input port for injecting the high-pressure high-concentration fluid, and a high-pressure outflow port for forming a mixed high-pressure outflow for re-concentration.