Water Turns Green

Conservation efforts are becoming a sustainability imperative at plants.

By Seán Ottewell, Editor at Large

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One of the major uses of water at Berkeley is in cleaning operations. They rely on high purity water also known as water-for-injection (WFI). Such water is expensive because it has to be purified by processes such as RO or distillation and then stored and distributed at high temperature. So reducing its use also pares site demand for natural gas and electricity. "Our evaluation has showed us that all our resources are linked, and making a conscious effort to reduce one resource can help reduce our overall consumption as well," notes Daszkowski.

Operations are benefiting from a new skid, designed by the Berkeley site's PAT [process analytical technology] group, to minimize over-cleaning. "This skid includes many of the types of analytics such as a total organic carbon (TOC) analyzer, dual wavelength UV analyzer, a pH analyzer, and conductivity analyzers that are used for cleaning validation, all packaged together in a real-time, inline process monitoring tool," says Chris Williams, BTS PAT manager. Early use of the skid points to a number of pluses, including an average water consumption reduction of up to 50%.

Pipeline projects are reaping benefits too. "The project team has looked at many other water savings through redesign of old systems. The RO system in one of our buildings sends close to 8 million gallons of water a year into our drains. Repiping the drain to our cooling towers lowered our consumption of city water and helped us reduce site consumption by approximately 7%," says Arun Nedungadi, sustainability engineer.

Another project reuses tower water that cools clean steam condensate, saving about 2.5 million gallons of water annually. "In addition, 1.5 million gallons of condensate that was being sent to drain is now being redirected to our main steam plant where a redesign of oversized pumps has halted excessive water-hammering," adds Nedungadi.

"Overall, these projects have helped cut water consumption at the Berkeley facility by 12 million gallons, approximately 10% of the total in 2010 -- this is a major step forward in helping us realize our 2015 goals," explains Ron Roberts, principal engineer, central utilities.

A key aspect of sustaining these changes is to engage company employees in the conservation efforts. "We will be looking to include employees in identifying and implementing projects by having dedicated energy teams for our mission-critical buildings on site," says David Woodard, principal, health environment & safety group.

As part of its overall sustainability goals, Air Products is committed to cutting its water consumption by 10% by 2015 versus 2009, and is promoting water reuse.

In addition, the company is helping its industrial clients improve wastewater treatment: "For industrials that have wastewater treatment plants, they can face challenges meeting production capacity changes. The desire to increase treatment capacity without major capital investment is a good application for oxygen," explains Miller. Retrofitting pure oxygen onto existing processes that rely on air and activated sludge can double treatment capacity (Figure 2), while adding high efficiency mixers at the same time can reduce power consumption by up to 50%, he notes.

Air Products also is helping customers to reuse their own wastewater, especially when significant quantities of organics or nutrients are present and use of oxygen is a good fit. There's a strong focus on MBRs because they are high-intensity, have a small footprint and produce very high quality water that can be reused in a number of on-site applications such as cooling-water makeup.

"However, while you get a lot more treatment/volume with an MBR, the use of high sludge concentrations can lead to limitations getting sufficient oxygen into the wastewater using conventional air-based aeration. So we believe that the optimum MBR design would run on pure oxygen. We have a couple of these up and running now in industrial applications and are close to commercializing a further optimized system," he reveals.

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