Water Sage

Water is essential for life—and ethanol production. To the ethanol industry, the name U.S. Water Services is as ubiquitous as they come, thanks to the company’s solid reputation developed over the past two decades, offering ethanol clients increased efficiencies, conservation of resources and boosted profits.

How did U.S. Water Services get its start?  

I had been working with Nalco for about 14 years in the sales division and really began seeing a shift in the industry with large-scale rollups taken by General Electric, Danaher and Nalco. I saw a need for a national alternative to middle-market companies that not only offered water treatment, but one that could offer system integration. That’s really what set the whole thing in motion. In 1997, I mortgaged my house, cashed in my 401K and with the help of Stacey, my wife, Randy Meyer, our acting chief sales officer and Mike Bertrang, our acting regional manager for the Minneapolis/St. Paul and surrounding territories, we began our adventure. We started out with zero customers and no revenue, but a unified vision to bring innovative and state-of-the-art water treatment chemistries together with the equipment and engineering side of the business into an integrated package that maximized on-site efficiencies for the customer.

We got our start in the ethanol industry by providing start-up water treatment services and programs to all but two of the ICM-constructed plants. I think what really helped us keep our stance in the industry, and continue to be a leader, is the fact that we innovate for the customer rather than to the customer. We strive to help them realize continuous improvement, developing products that help increase efficiency, production and profitability by removing bottlenecks in their system, which, in turn, help them stay competitive in the market. We realized a long time ago that success isn’t only defined by company growth and milestones; it’s also defined by helping customers realize their success in whatever way that is defined for them.

Could you explain U.S. Water’s integrated solutions approach to water treatment? 

What really differentiates us from our competitors is our ability to offer system integration combining water treatment chemistry and process chemistry, engineering, equipment and service that address a variety of concerns including safety, variability control, risk and or exposure mitigation, brand assurance, capital equipment integrity, yield, profitability, final ethanol quality and compliance. Part of the reason U.S. Water has seen so much success in the ethanol sector is our ability to use our integrated approach to find each customer a personalized solution. One size does not always fit all. By combining chemical, equipment, engineering and service into a seamless program, we provide not only continuous improvement to our customer base, but also measurable immediate and long-term ROI (return on investment).

What does “solution neutral” mean in your approach to water service? 

It means that we keep the customer’s best interest in mind. We train our representatives on chemical, mechanical and operational methods so they can focus on, and truly find, the best answer for the customer. It’s not just about the differentiated product offerings we provide; it’s the knowledge we’ve gained through years of earned industry experience that enables us to package these products together in a solution-neutral way—finding an optimal resolution to your most challenging water, process and energy needs.

How has water use at ethanol plants changed over the past 20 years?
 
Ethanol plants need a constant supply of water, from 3 to 5 gallons per gallon of ethanol, which equals approximately 500 to 2,000 gallons per minute (gpm), depending on plant size and efficiency. Water conservation is critical as risks of water scarcity, wastewater disposal limitations and sustainability issues mount. Consequently, water use in ethanol production has decreased by half in the past 20 years. The Renewable Fuels Association’s 2014 Ethanol Industry Outlook reports that, in 1994, 5.8 gallons of water was used to produce 1 gallon of ethanol. In 2014, this dropped to 2.7 gallons.
Further efficiencies in water and energy use in the industry are necessary to meet future regulations that will continue to limit water use and impose stricter water discharge regulations. Producers must find ways to minimize water treatment and discharge costs in order to afford costs incurred by potential changes in regulatory compliance requirements. Plant operators must also plan ahead, ensuring they can renew discharge permits, so it is essential to know the plant’s water footprint and operational effects of water quality in dry-grind ethanol production.
 
How can ethanol producers reuse, recycle and conserve water in their operations?

The ethanol production process requires significant amounts of water. Although process flows can be 600 to 1500 gpm, most is recycled within the process. Most of the approximate 40 to 100 gpm of water added to the process is added through the carbon dioxide scrubber. Just as an example, based on U.S. Water’s experience, a mechanical-operational-chemical program can improve scrubber performance and save 10 to 40 gpm of fresh water.

Other water- and energy-saving techniques include reduction or elimination of direct-injection steam-heating and returning condensate to the boiler along with redirecting boiler blowdown to the process, both of which recover high-quality water and energy; cascading water to lower-quality applications and operating cooling and boiler systems at higher cycles of concentration, both of which help conserve water; and using nontraditional water sources such as municipal graywater and plant stormwater.
Two practical complications with water reuse and recycling affect the process side of ethanol production. First, treatment chemicals added to the process remain in the grains, and so must be acceptable and approved for animal feed. Second, anything sent to the beerwell will end up back in the front end and can affect fermentation. The water quality requirements for process water are based on what is bad for the yeast. Limitations on sodium, chloride, sulfate, oxygen, organic acids and even silica are commonly specified.  

How big is zero-liquid discharge in the ethanol industry, and how does it work?

While zero liquid discharge (ZLD) systems have primarily been utilized due to a facility’s inability to discharge water, this impetus is changing as water quality and scarcity are becoming significant issues in many parts of the country. ZLD systems are now in use not only to eliminate discharge, but to save water—potentially reducing freshwater requirements by approximately 30 percent by eliminating wastewater discharges and optimizing water use within the plant. A well-designed system minimizes the volume of liquid waste requiring treatment and produces a clean stream suitable for use elsewhere in the plant. The majority of water in ethanol plants is evaporated, and this must be replaced. The key to reducing overall wastewater flow is to select, and optimize, the equipment and the flow-stream quality generated by the equipment.

An estimated 40 to 50 of the 216 conventional fuel ethanol facilities in the U.S. are operating as ZLD facilities, with several more in the process for discharge- or water-related savings. U.S. Water has helped plants achieve ZLD since 2006 with installation of the first-ever cold lime softening ZLD system in a dry-grind ethanol plant in Madera, Calif. We just completed our 16th ZLD installation most recently at Bushmills and are excited to see the resulting success. We’ve utilized multiple techniques to help customers meet discharge limits and reduce water use, including high-efficiency reverse osmosis, evaporators and crystallizers, as well as utilizing rainwater by using a skimmer and filter system and an evaporation pond to eliminate water discharges.