At most chemical plants, plant management and operators face increasing pressures to improve the energy efficiency of their processes. A snapshot of just how well the industry is responding to these pressures could be seen in last October’s announcement by the American Chemistry Council (ACC), Arlington, Va., of the winners of its 2005 Responsible Care energy efficiency awards.
A total of 11 companies received 26 awards in recognition of company-wide and plant-level achievements in implementing a wide variety of energy efficiency improvements. “Since 1970, Responsible Care companies have reduced fuel and power consumption per unit of output by 46%,” says Jack Gerard, ACC president and CEO. “In the past five years, these companies have reduced their greenhouse gas intensity by more than 26% ... These awards show that our industry is doing its part to increase energy efficiency.”
Although many of the awards were given for specific process-improvement projects, the importance of plant utilities in the overall energy balance wasn’t overlooked. Among the citations, for example, were ones to DuPont’s Sabine River Works, Orange, Texas, for its site energy-reduction program, DuPont’s Belle Plant, Belle, W. Va., for powerhouse efficiency improvements, and ExxonMobil Chemical for a cogeneration project at its Baytown, Texas, olefins unit and for furnace energy improvements at its Baton Rouge, La., plant.
Focusing on site utilities for energy efficiency improvements may have benefited those companies but not everyone appreciates the potential gains to be made from investing in what is still considered by many as a non-earning part of the plant. Steam systems are a case in point, particularly when it comes to steam trap management.
“The problem in the chemical and petrochemical industries,” says Mike Acers of James D. Acers Co., Cloquet, Minn., “is the view that steam traps won’t make the company any money. They’re looked on as a necessary evil to keep the process running.” Acting as U.S. distributor for the bimetallic steam traps manufactured by Velan, Montreal, Quebec, and Leicester, U.K., Acers says it can take some time to convince people of the cost benefits of good trap management.
Recognizing the importance
Not everyone in the industry needs convincing, however. Dan Dvorak, a consultant in the energy engineering group of DuPont Engineering Technology, Nashville, Tenn., says that steam traps and steam trap management are “basically the foundations or building blocks for steam system management. We have hundreds of steam-consuming sites worldwide — from office complexes through research facilities to production sites — and we know that if we don’t take care of our steam traps on some routine basis, after a few years we could have anywhere between 25% and 35% of a site’s traps in some failed condition.”
That estimate may understate the situation at other companies, according to James Risko, president of steam specialist company TLV, Charlotte, N.C.: “For a site that has not had a proactive trap management program with annual surveys and repairs,” he has reported, “it is not uncommon to have 50% of the trap population (or more) in a current state of failure.”
DuPont adopts a best practice approach to looking after an installed base of traps that, says Dvorak, “is probably on the order of a quarter-of-a-million or so around the world.” That best practice depends very much on the installation and application. For routine maintenance, for example, the plants’ SAP enterprise resource planning system will prompt manufacturing areas to inspect traps. “The best practice may have them do that at some routine yet optimized frequency,” he says. “So, if you were just starting out and had critical process traps, you might inspect those — depending on whether you were using on- or off-line technologies — continuously or once a month. It just depends on the installation. Our best practice basically says get the right trap for the right application and have something in place to ensure they are inspected at some routine periodicity depending on the application.”
Dvorak stresses that DuPont’s approach to traps and trap management is quite pragmatic. “We know if we don’t take care of such systems we would impact our fuel bill by anywhere between 8% and 10% a year. We have data to support that.”
Acers also can provide data to show the value of good trap management, such as the results achieved at Murphy Oil’s Superior, Wis., refinery. Velan started work there back in 1998, analyzing the condition of the site’s 3,000 steam traps, and recommending upgrades and replacements of failed traps where necessary. The original work, including leak repairs and improvements to the condensate recovery system, took four months and a similar project has since become a biennial ritual — with significant energy savings as a result. The annual failure rate of Murphy’s steam trap population has dropped from 21% in 1998 to just 3.4% last year.
“When it comes to steam traps, people often ignore them,” says Bruce Gorelick, president of Enercheck Systems, Charlotte, N. C., an energy consultancy that works in collaboration with ultrasonic-testing-equipment supplier UE Systems, Elmsford, N.Y., to advise plants of the benefits of steam trap surveys. “There’s a complacency about them that is costing steam users much more than they realize,” he adds.
As Acers says, “steam traps are an old, old product,” which possibly explains, but doesn’t excuse, their relatively low profile at plants.
Although all traps are designed for the same function — basically to release condensate and non-condensable gas (air) from a steam system while preventing the escape of live steam — there are many types of traps for many different applications. (For selection guidance, read Find the perfect steam trap.)