The Natural Energy EngineTM as a
Low-Cost Power Source for Reverse Osmosis Desalination       

 The Thermal Hydraulic Engine from Deluge, Inc. represents a breakthrough technology that can perform the work of similar engines at a fraction of the operating costs while releasing no emissions into the air. Also known as the Natural Energy (NE) EngineTM, this patented, innovative engine (U.S. Patent Number 5,916,140) employs alternative heat sources such as solar, geothermal, and waste heat energy, as well as fuels like natural gas, to convert hot water into mechanical power without combustion. Under development by Deluge since 1996, the NE EngineTM has been use-tested in numerous applications including oil and gas pumping, water pumping, desalination, electricity generation, compression, and air handling, and can operate as effectively in third-world countries as in highly industrialized countries. Initially conceived as a replacement for the internal combustion engine, the NE EngineTM has attracted the attention of many companies in the oil and steel industries who want to use this pioneering, clean, and cost-effective technology as a way to lower production costs. The technology’s cost effective and environmentally-innocuous features make it an attractive power source for most any application, including pumping water for desalination processes.

How the Thermal Hydraulic Engine Works

As noted above, the NE EngineTM uses alternative heat sources to power applications like water pumping. The engine’s mechanism involves first heating a working fluid like liquid carbon dioxide (CO2) by running hot water (heated by solar, geothermal, or other heat source) through a heat exchanger reservoir. The liquid in the reservoir expands and pushes out a piston, which is attached to a common rod that compresses the process water. A timed valve system then switches from a hot water flow to a cold water flow, which cools and contracts the working fluid, pulling the piston back to its original position and preparing the engine for another cycle. Optimal temperature differential between the hot and cold water is 100o F, with typical temperatures used approximately 80o F and 180o F.

Using the Thermal Hydraulic Engine for Reverse Osmosis Desalination

One of the most promising potential uses for the NE EngineTM is affordable water desalination. Testing has proven that the NE EngineTM is an effective alternative to the conventional electric motor in forcing water through a reverse osmosis (RO) membrane. Reverse osmosis is a liquid-liquid separation process that employs a dense semi-permeable membrane that easily permits water to pass through it while blocking microorganisms, colloids, and salts. The only requirement for the RO process to take place is that applied pressure overcomes osmotic pressure. The NE EngineTM is very suitable for pumping water in a reverse osmosis process because it effectively overcomes inertia and provides a sufficient amount of pressure for water filtration.

Scientific Performance Testing of the Thermal Hydraulic Engine

To evaluate the potential of the thermally driven Natural EnergyTM Engine, a study was conducted in 2004 by Deluge, Inc., the U.S. Department of the Interior Bureau of Reclamation at the Water Quality Improvement Center (WQIC) in Yuma, Arizona, and Arizona State University Fulton School of Engineering. The study was designed to test the effectiveness, cost, and efficiency of the engine in a reverse osmosis desalting process using a variety of source waters. The primary objective of the project was to prove that the Natural Energy EngineTM could be used as a high pressure pump to pressurize brackish water and force it through a reverse osmosis membrane. Another objective was to verify the NE EngineTM could substantially decrease the cost of desalination, as current reverse osmosis systems require enormous amounts of electricity for pumping water through an RO membrane, greatly increasing the cost of producing treated water.

The Natural Energy EngineTM was tested by connecting it to a Membrane Test Apparatus (MTA) furnished by the Bureau of Reclamation, providing the engine with a supply of hot (180F) and cold (80o F) water required to fuel it, and then observing the resulting pressures and flow rates through an RO membrane. The MTA was fitted with instruments with local readout gauges which also transmitted to a data logger that downloaded data to a laptop computer. Instruments included feed water pressure, reject pressure, process tank PH, reject conductivity, product conductivity, product flow rate and reject flow rate. The product conductivity determines the parts per million (PPM) of the fresh drinking water. Parallel testing also was conducted using a conventional electric motor to allow for a side-by-side comparison of data derived from the two types of energy production. The tests employed both engines in pumping 2000-PPM saltwater through a reverse osmosis membrane to yield a product flow of 50-PPM freshwater. The baseline tests performed on the conventional electric motor were performed five times each for 20 minutes in duration, both before and after the tests were performed on the NE EngineTM.  The Natural Energy EngineTM was tested under two conditions, with Test #1 performed twice (once for 40 minutes, once for 2 hours) and Test #2 performed once for 2 hours.

Results and Significance of Test Outcomes

Outcomes of the testing revealed comparable functionality between the Natural Energy EngineTM and the conventional electric motor in pumping 2000-PPM saltwater through an RO membrane. Both engines yielded a 50-PPM freshwater product flow at the rate of one liter per minute using a comparable level of feed pressure to pump the water. The results of the tests performed in the study substantiated that the NE EngineTM can successfully pressurize water and force it through an RO membrane with similar efficiency to a conventional electric motor. Since the Natural Energy EngineTM requires only about 10% the electricity used by a conventional electric motor, operational cost savings of up to 90% can be realized. Table 1 presents the performance testing outcomes comparing the NE EngineTM with a standard electric motor.

Table 1. Comparison of TH Engine and conventional electric motor

Variable/Parameter Tested

Natural Energy EngineTM

Conventional Electric Motor

Initial amount of current (first 30 minutes) in Amps needed to pump one liter per minute of 50-PPM water

~1.2 Amps

15 Amps

Ongoing amount of current (after first 30 minutes) in Amps needed to pump one liter per minute of 50-PPM water

~1.2 Amps

12 Amps

Feed pressure at one liter per minute product water flow

< 3000 KPa

2870 KPa

Total (product and reject) flow of water pumped through RO membrane yielding one liter per minute product water flow

~6.3 Liters

6.3 Liters

Total cost for electricity



Cost Savings from Converting from a Conventional Electric Motor to an NE EngineTM

Estimating  cost based on a 220 Volt AC source use at $0.10 per kilowatt-hour, running this motor for about 2 hours would cost a little over $0.48, with an energy usage of about 4.85 kilowatt hours (kWh). As stated above, because the NE Engine uses about 10% of the electricity, an impressive 90% less electricity will be used. The electric motor RO system will cost about $2,100 per year to run. Building an NE EngineTM and adding it to an RO plan would require a more in-depth study of the balance of plant and facilities available. The inventor’s prototype cost approximately $4,000 to build—$2,500 for the piston, $1,000 for each heat exchanger, and $500 for the other system components, which includes the valves, pipes, and fittings. The $4,000 price tag represents a one-at-a-time cost for building a single engine. The NE EngineTM naturally would be cheaper to produce in mass production, where a discount price could be negotiated with original equipment manufacturers.

The full report of the research study entitled Measuring the Performance of a Thermal Hydraulic Engine Used in Pumping Water for the Reverse Osmosis Process (Hageman et al., 2005) available upon request.

Text to Linked Material

Deluge, Inc.

Deluge was incorporated in 1996 with the objective of developing a Thermal Hydraulic Engine, invented by Brian Hageman, exhibiting breakthrough technology driving exceptionally low operational costs with absolutely no emissions into the atmosphere. Current applications include oil and gas pumping, water pumping, desalination, electric generation, compression, and air handling. The engine converts hot water into mechanical power without combustion and can operate just as effectively in third world countries as in highly industrialized countries.

Water Quality Improvement Center (WQIC)/ Bureau of Reclamation

The Bureau of Reclamation is an agency within the U.S. Department of the Interior and is the largest wholesale water supplier and the second largest producer of hydroelectric power in the United States, with operations and facilities in the 17 Western States. Its facilities also provide substantial flood control, recreation, and fish and wildlife benefits.

The Water Quality Improvement Center (WQIC) is a National Center for Water Treatment Technology, operated by Reclamation’s Yuma Area Office. Located at the site of the Yuma Desalting Plant (YDP), the WQIC explores technologies to reduce the costs of operating the YDP, and partners with others to speed the adoption and use of water conservation technologies such as those used in desalting.

Arizona State University Fulton School of Engineering

The Ira A. Fulton School of Engineering at Arizona State University (ASU) is one of the nation’s top-ranked programs for engineering, computer science and construction students. The school is located on the main campus in Tempe, Arizona, five miles from Phoenix Sky Harbor International Airport.

The faculty of the Department of Mechanical & Aerospace Engineering (MAE) at ASU is dedicated to the continued development of excellence in its research and teaching programs. Research in certain areas of design and manufacturing, aerodynamics and fluid mechanics, heat transfer, mechanics and materials, and system dynamics and control receives international recognition.

Hageman et al., 2005

Hageman, B., Norris, M., Adams, A., Aguayo, V., & Phelan, P. (2005). Measuring the Performance of a Thermal Hydraulic Engine Used in Pumping Water for the Reverse Osmosis Process.

Contact information for report authors:

Brian Hageman, President and CEO
Deluge, Inc., and Inventor of the Thermal Hydraulic Engine



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