Energy Recovery’s Pressure Exchanger Makes Fracking Cleaner, Safer And Simpler

The heightened awareness and focus on ESG (Environment, Safety and Governance) considerations by investors, regulators and customers has raised the stakes for companies in all industries in recent years, and oil and gas ranks near the top of the list. In fact, the pressure to convert ESG considerations from liabilities and negative reputational risk into profit and core achievement is probably as high on fossil fuel producers as it is on any other industry. For many companies, the ability to demonstrate substantial improvements in these arenas either has or soon will become a literal matter of survival.

This external pressure is driving a search for solutions that will likely result in radical changes in the way most industries look, sound and operate in the years to come. A San Leandro CA based company called Energy Recovery

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offers one such solution that has only recently begun to gain traction.

On a recent trip to San Leandro to tour the company’s main facility and talk with members of its executive leadership, I discovered that Energy Recovery is not one of those technology companies that offer a vast array of hardware and software designed to address specific areas; it is instead a company with a seemingly simple, elegant core technology, a pressure exchanger (PX) that it has spent the last 29 years finding ways to apply to an array of energy-related applications.

“The first application was in desalination, and it helped change the industry” Robert Mao, the company’s Chairman, President and CEO told me as we sat down in the company’s board room.

“And we are now using it to address similar issues in other industries – refrigeration, oil and gas, and wastewater treatment specifically. The PX is a solution for many industrial challenges, reducing energy needs and associated emissions, and as crucially, saving money for our customers.”

Founded in 1992, Energy Recovery is headquartered in the Bay Area in an industrial area near Oakland International Airport. From small beginnings with just a few employees, the company now boasts more than 200 employees in San Leandro and its two satellite operations in California and Texas, along with a market cap of $1.2 billion.

Getting to this point was a long, difficult process, as the desal companies were initially slow to adopt the company’s exchanger, an innocuous-looking cylinder in a yellow housing with only one moving part. “It was such a novel idea that it took a long time before people began to adopt it,” Mao said. “But over time, as the industry became more familiar with the technology and how it could impact their business, adoption sped up considerably.”

Mao said that there was another key factor that helped: “Over time the membrane technology improved. We push water against a membrane, and if the membrane collapses all the time, it gets expensive. It takes two to tango.”

The technology itself is elegantly simple: It involves a rotor inside a tube-like housing. High-pressure fluid from a desal or fracking operation enters one end, and low-pressure fluid enters the other. The fluids act as the fuel to turn the rotor, which takes the pressure from the high-pressure fluid and moves it to the low-pressure fluid, which is then returned and re-used in the operation. It requires no fuel of its own and creates no emissions.

“The reason why our device is so efficient is because it does not have any of the mechanical components that go into a typical pump. We only have one part that actually spins, the rotor. Nothing else moves,” Farshad Ghasripoor, the company’s Chief Technology Officer, told me.

“The fluid is the piston,” he continued, “It’s a virtual piston. The energy exchange takes place within the rotor, and you can convert that energy from the high-pressure fluid to the low-pressure fluid, which then comes out as the high pressure fluid. Everything is lubricated with the fluids that we pass through. And because of the tiny gaps between the parts, that fluid also acts as your bearing and cooling fluid. The reason why this thing is about 97% efficient is because you only have a small amount of fluid used to lubricate the bearings.  It’s a very simple concept.”

Because the rotors and housings are meticulously machined to micron tolerance levels, there is essentially no heat-producing friction created by the spinning rotor. As a result, the pressure  exchangers almost never fail. As Mao told me, the company’s early strategy was to compete on price, but the near-zero maintenance and replacement costs of its equipment created profitability issues.

“In 2014, a former CEO at the time asked the question: Why are we competing on price?” Mao said. “Our equipment never fails. We don’t have maintenance. So, why are we competing on price?” This realization resulted in a change in strategy.

“Today, we’re really competing on no down-time. As desal plants get bigger and bigger, every day of unscheduled down time costs a lot more money. Once we went away from that [competing on price], then we started consistently making a profit.  From 2015 onwards, we have continued to build a dominant global position in the market.”

Anyone who has ever witnessed a high-pressure hydraulic fracturing job, with their arrays of dozens of big, loud high-pressure pumping units typically powered by diesel or natural gas, can quickly grasp the potential benefits offered by Energy Recovery’s pressure exchangers.

• Their use can dramatically reduce the number of pumps required for any job.
• Because they sit downstream of the pump and can handle both water and frac sand, the frac pumps are able to handle pure water only, resulting in significant reductions in maintenance and down time.
• Fewer pumps mean less noise, lower fuel costs and reduced air emissions, all key considerations in the ESG world.

Fracking is not the only area of the oil and gas business to which this simple technological solution can be applied. It can provide a similar benefit in natural gas processing plants, in the removal of hydrogen sulfide (H2S) from gas streams. For this application, the company has developed what it calls its ISO Boost unit, which operates on the same basic pressure exchanger concept.

“The process to remove the H2S is based on using a solvent [amine] that is pumped into a contactor at pressure, and as it contacts the gas it absorbs H2S from it,”  Ahmed Ghoneim, Vice President of Oil and Gas, told me. “The amine leaves the contactor still at high pressure, but to remove the H2S you must then drop the pressure. So, the process itself involves a pressure drop, from 1,000-1,200 psi down to 100 or so psi, depending on the design.”

“This is where we come in: Wasted pressure provides an opportunity to capture that energy, move it from that side – which is called the rich Amine – and transfer that pressure to the lean side, the clean amine that would go into the contactor. So, instead of having to raise the pressure of that solvent back from the 40, 50, 100psi back to 1,000 psi, the ISO Boost captures that pressure and moves it to the other side.” All of that translates into power savings directly proportional to the amount of pressure we moved from one side to the other.

“It provides a very reliable solution because there are no seals that have the potential to leak. More importantly, it drops the costs of power consumption significantly, by 50% or so.”

Just as with the use of the pressure exchanger in fracking, the potential ESG-related benefits become quickly obvious. Treatment and reuse of oilfield wastewater is another area where this technology could deliver obvious benefits, and the company is in the beta-testing phase for a number of wastewater treatment market applications including landfill and lithium battery production in India and China.

Mao acknowledges the role regulations are currently playing in raising the attractiveness of his company’s technology, but also cautions that the “regulatory push”, as he calls it, will have to live within the limits of present economic realities.

“Everything we do today has a tailwind, which is the regulatory push,” he said. “It is there, regardless of what country you are in. It’s just about how accelerated and how strict, but it’s all there. And the regulatory push is to save this Earth.”

“But I always believed that, even a regulatory push can only be done to the extent that you don’t kill people’s livelihoods. So, you have to have a situation where the regulatory push is aided by economics. Our technology is helping both customers and regulators achieve their goals.”

“For example, in the  global effort to replace HFC refrigerants with natural refrigerants such as CO2, our PX technology has the potential to do what we did in desalination – make a formerly expensive process more financially attractive and sustainable. This can be a win for both regulators and large-scale refrigeration users such as your local supermarket.”

That of course is an equation every sizable energy company is going to have to solve in the coming years: How to meet the ESG-related demands of governments, investors and customers while still maintaining profitability. Management teams at these companies are being presented with a vast array of potential technological solutions every day of the week, but one thing is certain: No company’s offering will be simpler in concept and provide benefits that are easier to grasp than Energy Recovery.

If I can understand it, pretty much anyone can.