Harvesting humidity: A sustainable solution for a water-stressed world

Global warming and industrialization are rapidly depleting the world’s supply of fresh water. The looming water shortage was identified at the 2015 World Economic Forum as the number one global risk, with profound effects on health, education and the economy.

Dr. Majid Bahrami, Canada Research Chair in Alternative Energy Conversion Systems at Simon Fraser University, feels strongly about the need to address the global water crisis. At the same time, as a former HVAC and refrigeration industry engineer and consultant, he also values real-world problems as teaching opportunities.

Over the past three years, the Mechatronics Systems Engineering professor and his PhD student Farshid Bagheri have been working to find a viable, sustainable solution for water scarcity. Their answer is the Hybrid Atmospheric Water Generator (HAWgen), a green, reliable, low-cost system that generates clean, drinkable water from the atmosphere.

“Our atmosphere contains nearly 13 trillion cubic meters of renewable fresh water,” Dr. Bahrami explains. “This water is sustainable – no matter how much you extract, it is automatically replaced because of evaporation from our oceans.”

Unlike conventional atmospheric water generators, which rely on hot and humid ambient environments, or other water treatment technologies that require “feedstocks” (such as water) to function, and produce caustic byproducts, the HAWgen can generate potable water in nearly all climatic conditions, without the environmental impact of traditional systems.

The HAWgen uses a three-step process: first the incoming air stream is pre-conditioned using an adsorption system; then it is channeled into a refrigeration unit for condensation. The final stage filters the generated water, including ultraviolet treatment, producing pure, safe water.

The technology creates its own ambient humid environment by absorbing moisture through highly porous materials that then releases the humidity into the machine. “There is always a hot air stream coming into our condensing unit instead of ambient air, and this results in huge improvements in water generation capacity,” Dr. Bahrami explains. “It’s like a battery for humidity, in the sense that it dampens incoming air, creating a consistently humid ambient air stream.”

Their pre-market prototype generates 40 litres of water a day over 24 hours, which is 500% more than conventional systems, at one-third the operating cost. This prototype is powered by electricity but they have developed a renewable energy version that can operate under solar thermal power or waste heat from co-generation.

Designed with the help of CMC-enabled software and simulation tools such as COMSOL and ANSYS FLUENT, and developed in Dr. Bahrami’s Laboratory for Alternative Energy Conversion, the system has just completed its performance testing, the professor says.

The HAWgen forms the basis of WATERGENICS Inc., an SFU spinout and Dr. Bahrami’s newest commercial venture, with scaleup and commercial launch of the product expected in the next 12-18 months. In addition to consumer use, the company is targeting applications in mining, agriculture, oil, gas, energy and manufacturing, as well as in military field operations and disaster relief.

The next hurdle is getting the technology into the hands of users, he says. Interest has already been expressed by potential customers in the agriculture and mining industries, and by at least one African country.

The technology is one of many clean innovations developed by Dr. Bahrami and his students. In November his work in sustainable technologies was honoured with a 2016 Canada Clean 50 Award (Research and Development category). The awards recognize Canadian individuals or teams who have advanced sustainability and clean capitalism in Canada over the past two years.

“We are blessed in Canada with an abundance of water, but we don’t have to go far to see people suffering,” he says. “If I as an inventor can do something to help alleviate the pain a bit, this would be great. It’s an exciting time for us.”

March 2016

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