Evaluation and Optimization of Emerging and Existing Energy Recovery Devises for Desalination and Wastewater Membrane Treatment Plants
Year Released: 2013
Type: Decision Making Tool
Funding Partner: Bureau of Reclamation, California Energy Commission
Total Investment: $435,082.97 (Cash)
Principal Investigator: Robert Huehmer, CH2M HILL
Reverse osmosis (RO) is widely used to desalt brackish water and seawater for drinking and industrial water production and to reclaim wastewater effluent for potable reuse and industrial use. A major impediment to additional implementation of desalination technologies is the lack of an independent tool to evaluate energy consumption and minimization of energy use.
Goals and Objectives
The project creates a thoroughly researched guidance manual that assesses currently available and emerging Energy Recovery Devices (ERDs) for desalination systems, and to create a computer tool to evaluate commercially available ERDs for the treatment of brackish water, seawater, and wastewater effluent.
A literature review and manufacturer assessment was conducted on energy recovery devices and their use in the desalination of brackish water, seawater, and wastewater. Based on typical municipal requirements, an integrated mass-balance, reverse-osmosis projection software, energy recovery, and cost estimating model was developed. The Excel-based tool permits utilities, engineers, and plant operating staff to provide greenfield, cost-based decisions on which, if any, commercially available energy recovery device to implement in their desalination facilities.
Findings and Conclusions
To fill a need in the desalination community, an Excel-based computer tool was developed with the following functionality:
- RO mass balance
- RO projections
- Incorporation of ERDs
- Calculation of power consumption
- Estimation of capital costs
- Estimation of electrical operating costs
The tool allows the user to develop an optimum RO system design (such as number of stages, recovery and flux, and flow and pressure of various streams) based on feed water quality and desired product water quality. The membrane type (low-pressure or high-rejection), number of passes, percentage of bypass, and ERD are examples of the options available to the user to customize the model run to a project. The tool is based upon common process configurations utilized in desalination plants.
The tool output will show the energy consumption when no ERD is used, display comparative performance (based on energy consumption, operating costs, and life-cycle costs) of these devices, and indicate the overall energy consumption, operating costs, and capital costs associated with the system.
The tool provides a valuable new resource for municipal planners, operators, and consulting engineers in evaluating energy recovery options in desalination of brackish water, treated wastewater, and seawater using RO technology.
The download for this project includes both the guidance manual and the tool.
NEW! This tool has been updated to include 2014 costs in the Excel-based cost estimating tool. The new release includes updated costs for all equipment as well as minor improvements to ERD efficiency calculations as recommended by the equipment vendors. An addendum summarizing the 2014 update is included.