Energy Consumption Of Reverse Osmosis Research Articles

Experimental study on integrated membrane processes in the treatment of solutions simulating textile effluents. Energy and exergy analysis

Membrane processes in the textile industry can minimize pollution phenomena contributing also to decrease energy consumption, to increase product quality and improve the overall process efficiency. In this study the energy consumption of simulated textile processes have been analyzed and compared with systems where membrane technologies have been introduced. The value of dye and salt concentration which might be reached have been tested in a reverse osmosis pilot plant. The hydrodynamic characteristics of the spiral wound modules used and evaluation of their efficiency in terms of rejection, fluxes and life time of the membranes are reported. The possibility of reaching higher concentration of chemicals by membrane distillation, using the concentrate of reverse osmosis as feed, has also been studied. Based on experimental results, an energy and exergy analysis was attempted. Substitution factors, related to the electrical energy consumption in reverse osmosis and in an integrated reverse osmosis — membrane distillation process have been calculated and compared to cycles with chemical recovery and without recovery.

Distillation and reverse osmosis energy consumption and costs

The paper compares the energy requirements of single and dual purpose MSF distillation with seawater reverse osmosis plant. Energy consumptions are given both as heat and power consumptions for distillation and as power consumption for R.O. To enable a true comparison to be made these inputs are referred back to the heat inputs from fuel needed at the boiler plant or appropriate thermal power plant. Energy recovery is also considered for reverse osmosis and it is shown that the energy input can be expected to decrease by some 35% for a typical example. Although the prime energy input needed for reverse osmosis is shown to be substantially lower than for dual purpose distillation, the overall costs taking account Of capital charges, energy, replacements and other operating costs, are found to be in a band width of about 5% for plants in the range of 5000 to 15000 m 3/day. Reverse osmosis plant water costs are significantly less than distillation if membrane life increases from 3 years to 5 years, particularly with small plant capacities.