Optimising energy consumption in SWRO systems with brine concentrators

Taking three examples of plants with brine concentrators, we analyse energy consumption of existing and projected systems. This includes plants using Turbocharger boosting system, Turbocharger boosting with additional Impulse turbine and Impulse turbine acting as boosting and recovery system. Energy consumption of the high pressure systems and the high pressure pumps are compared. Sites analysed are Curaçao and a 7,000 m³/d and 15,000 m³/d projected trains. Component optimisation is undertaken to achieve the lowest possible energy consumption of the SWRO plant. This investigation shows that an energy consumption of 2.58 kWh/m³ product water is possible for the complete high pressure feed pump system.

The analysis demonstrates that a close cooperation between system component manufacturers must take place in the early planning stage of a SWRO plant project. This is the only way to optimise the components design data, resulting in the reduction of energy consumption and the TCW (total cost of water). High-pressure train energy consumption as low as 2.58 kWh/m³ product is possible.