By Jim Montague, Executive Editor
Are you light, superficial green? Or are you dark, committed green? For instance, anyone can put a variable-speed drive (VSD) on pumps, fans and other rotating equipment—and almost everyone should, but that's only a good beginning.
Certainly, $4 to $5 per gallon gas and other skyrocketing energy costs are gouging consumers, businesses and manufacturers alike, so many are undertaking efficiency projects to meet public, investor and government demands. Some programs include the U.S. Environmental Protection Agency's Energy Star program (www.energystar.gov), sustainability scorecards from Walmart (www.walmart.com) and P&G (www.pg.com) and the Dow Jones Sustainability Indexes (www.sustainability-index.com). However, some individuals and organizations are also asking if they can alter process applications and even questioning whether they need to run some processes at all. These pioneers are trying to take sustainability beyond its initial focus to include making products that are themselves greener and allow users to operate and live more sustainably. In short, sustainability is longer-term and focuses on a widening circle of processes, material producers, users and consumers, while efficiency concentrates on traditional, here-and-now improvements in one or a few devices or operations.
Low-Hanging Efficiency Fruit
Still, despite its narrower focus, basic efficiency can improve operations in huge numbers of equipment and applications, produce massive savings and lay the groundwork that leads to future sustainability.
For instance, China National Petroleum Corp. (www.CNPC.com) recently implemented Invensys Operations Management's (ion.invensys.com) SimSci-Esscor ROMeo process optimization software and services at its Jilin Petrochemical Co., which is reported to be northeast China's largest integrated refining and petrochemical production facility (Figure 1). CNPC is using ROMeo to formulate real-time responses to changes in utilities prices, feedstock variation and process conditions to achieve sustainable energy savings. CNPS reports that the software's off-line operational analysis and on-line plant modeling for ethylene production also lets it study and validate the feasibility of various energy-saving strategies and parameters affecting energy saving before implementation. ROMeo was applied to Jilin's entire ethylene complex, including 10 cracking furnaces and quenching, compression, cracking and separation equipment across its 700,000 tons-per-year ethylene production unit, and helped reduce the refinery's energy consumption by 5% overall.
"CNPC is devoted to reducing our worldwide carbon emissions, and one of the best approaches is to invest in technology that can maximize our energy efficiency," said Liu Hongji, deputy factory director at CNPC Jilin. "ROMeo software helps us save energy, improve visibility into our operations and drive productivity. It also reduced the energy consumption of our ethylene production unit and improved the whole plant's effectiveness."
Similarly, to reduce its huge gas, electric and water bills and comply with national energy use and emissions regulations, Lian Yuan Steel (www.lysteel.com) in Loudi City, central Hunan province, China, had already upgraded its equipment and processes, but recently decided to seek further gains by consolidating the plant's comprehensive energy data and analyzing it for improved scheduling and management decisions. The 1200-square-meter plant and its 15,000 employees coke, smelt, sinter and roll more than 6.5 million tonnes of sheet, rebar and other steel per year and earn more than $3 billion (Figure 2).
As a result, LY Steel's engineers worked with Schneider Electric's energy management solutions (EMS) division to implement its Citect-based SCADA and historian software, as well as six SCADA I/O servers with 30,000 variables, 5000 alarms, 3000 trends, one historian server and two SQL servers—all with less then one-second observed response time. This SCADA solution communicates with many different hardware systems used at LY Steel, including Siemens and the former GE Fanuc PLCs and electric meters that use special protocols, such as IEC-60870-104 or DNP#3.
Shortly after implementing Schneider Electric's EMS tools, LY Steel reports that it achieved a dramatic 50% improvement in its energy efficiency, 70% reduction in maintenance costs and a comprehensive savings of $3 million per year.
In addition, the historian helped bridge the intelligence gap between the plant floor and management, and provides an accurate, long-term data management and reporting system to enable better decisions. LY Steel's project manager, Wenyi Wang, adds that one of the EMS' most important benefits is that it enabled a change in the plant's management concept from decentralized to a leaner structure. "This automation technology facilitates energy management across our enterprise and gave us a professional and efficient diagnostic tool that helps us optimize our energy efficiency," says Wang.
Similarly, to help users gather the data needed to improve their efficiency and sustainability, Iconics (www.iconics.com) is launching its Energy Analytics software to aggregate and organize information from many process equipment sources and its Facility Analytics software to predict where possible energy offenders will arise in a given application.
Likewise, Parsec Automation Corp.'s TrakSys software also enables users to collect and organize large amounts of diverse process performance data to monitor and improve their energy productivity per item produced.
APC's New Role
Luckily, another of the best bridges between efficiency and sustainability is well-known in many process industries—advanced process control (APC). Though historically used mostly in big-ticket processes, APC is finding wider acceptance as its costs decline and as green efforts ramp up because its sophisticated data analysis and modeling methods can help extend efficiency into the wider sustainability world.
For example, Canadian fertilizer manufacturer Yara Belle Plaine Inc. (www.yaracanada.ca) of Belle Plaine, Saskatchewan, recently sought to improve its new nitric acid plant's energy efficiency by implementing advanced process control (APC) to maintain consistent, stable, high levels of production, while simultaneously achieving tighter control of its greenhouse gas emissions. Yara is one of the largest producers of granular urea, urea ammonium nitrate and anhydrous ammonia in North America (Figure 3).
Specifically, Yara's engineers wanted to control the amount of NOx leaving their catalytic combustor, while minimizing fuel gas consumption. "We needed to maintain NOx emissions below 200 ppm while minimizing the use of fuel gas. We also needed to maintain the combustor temperature within an appropriate range—hot enough to power the expander, but not hot enough to damage it or the platinum gauze in the combustor," says Mark Sax, Yara's controls engineer. "We also saw the combustor as a potential bottleneck to increasing nitric acid production."
Fortunately, Yara had just upgraded its control system to Honeywell Process Solution's Experion PKS, and now wanted to apply APC to it. The plant's engineers had also recently replaced their old NOx analyzer with a more reliable and accurate one. They estimated they could use Honeywell's Profit Controller application in an Experion Application Server (EAS) node that covers the whole nitric acid plant, and they implemented it over three months.
Conservatively, Yara estimates its APC project increased its nitric acid production by 3%, while tighter control of the combustor's outlet NOx permits a higher average combustor temperature, which allowed it to reduce methane emissions by 25%. Despite these gains, Sax says the project's biggest impact is that it makes Yara's operations much more stable and consistent and reduces plant upsets.
"When the operators run the plant in manual they can push the unit pretty well to its limits, but sometimes they end up swinging the unit," explains Sax. "With the new controller, the plant runs in nice flat lines, so we can achieve higher sustained production levels because it is so stable. Operator focus on the nitric acid unit has been considerably reduced, allowing them to be able to focus more closely on the urea plant that they also operate."
Similarly, Tom Kinney, Invensys' solutions developer, reports that his firm has worked with Abu Dhabi Gas Liquification Co. (ADGAS, at Das Island in the Persian Gulf to minimize traditionally variable and inconsistent fuel gas system flaring levels. ADGAS and Invensys first installed ExperTune's PlantTriage to identify valves that needed to be fixed and loops that needed to be tuned, and then implemented an APC approach using quadratic calculations to better match gas supply with demand from the application's boilers.
PlantTriage helped ADGAS reduce its former gas flare burn-off rate of 5.5-6 million cubic feet per day by half, and the APC solution cut it in half again for a total reduction of about 84%, which was worth about $3 million per year. "My advice is to do both, because PlantTriage can help other tools provide additional benefits," adds Kinney. "These two technologies gave us more benefits than either could have done alone."
Conserving Resources and Future Green
As process users and their applications migrate from basic efficiency to adding sustainability, most go from just saving energy to also conserving raw materials and other resources. And, once they catch the sustainability bug, they find more ways to go green. In fact, once efficiencies have been secured and resources conserved, it becomes apparent that sustainability and its supporters can return the favor to efficiency by developing some new versions of traditional applications and industries, and then eventually creating new ones.
For example, since Jeff Lebesch began making his Fat Tire Amber Ale in 1991, his New Belgium Brewing Co. (www.newbelgium.com) has grown to occupy a 50-acre campus in Fort Collins, Colo., with multiple brewing processes, water processing systems and building and facility management systems, which are monitored and controlled by more than 10,000 digital and analog I/O points that are organized into eight control zones. Seven of these zones, including the brewhouse, filtering, malting, yeasting, cellaring and other complicated brewing processes, are controlled by Opto 22's SNAP programmable automation controllers (PACs), which monitor and regulate oven temperatures for drying and roasting the grains, machines that crush and mash them, and water and resting brew mixture temperatures. To help power all its brewing and support operations, New Belgium has used a series of wind turbines for more than 10 years.
Using control strategies designed and programmed by New Belgium's own automation team, Opto 22's hardware also handles all other processes relating to brewing, such as boiling, blending, temperature and pressure regulation, and complex cascading proportional integral derivative (PID) control loops, where the output of one PID loop calculation is used as a process variable input for calculations in a second PID loop.
In fact, Igor Valuyev, New Belgium's chief electrical and automation engineer, has programmed Opto 22's SNAP PACs to operate New Belgium's fermentation systems differently based on the type of beer being brewed. The SNAP PACs at New Belgium can perform up to 96 PID loops, which more than meets its needs.
"We have many different malt recipes. To ensure that each comes out perfect, the Opto 22 systems must perform to very specific operational standards," says Valuyev. "Mashers, mixers, milling systems, chilling systems, filtration systems and our other equipment must all be made to work together."
More recently, the brewery redoubled its commitment to sustainability by installing its own water-treatment facility, which transfers wastewater from New Belgium into a series of large ponds, and treats it with bacteria that feed on and break down organic waste. As with the brewing processes, SNAP PACs monitor and control the treatment plant's aerobic and anaerobic water treatment, including pH stabilization, sludge
dewatering and auxiliary processes. The byproduct of this pathogen purification treatment process is methane gas, which collects in a huge balloon-like container, is piped back to the brewery and fuels a combined heat and power engine that produces electrical and thermal energy. In fact, 10-15% of the brewery's power comes from this co-generated methane, which significantly decreases New Belgium's electrical demand on Fort Collins.
Likewise, Granger Electric (www.grangernet.com) in Lansing, Mich., has developed a process for extracting, refining and selling methane from decomposing organic waste in landfills. Its method uses wells to oxygenate the waste mass and expedite decomposition, recover raw biogas before it escapes and separate the methane from it. For example, one of its largest projects, Conestoga Landfill Gas Recovery near Lancaster, Pa., supplies a large food ingredient supplier located 13 miles away with enough methane to power its boilers and keep the whole plant operating. Because this biogas substitute costs about half as much as natural gas and required only the resizing of a few pipes, the food company was able to dramatically cut its power bill. "It was just another supply link that had to be put in and retrofitted into the user's existing scheme, but the cost was quickly recouped by the savings received from our program," says Joe DiFerdinando, Granger's electrical engineer.
To monitor gas-flow variables and usage, Granger outfitted the food plant's buildings with Rockwell Automation's CompactLogix Ethernet-capable PACs, and then linked them to the PACs via ProSoft Technology's water- and dust-tight, 802.11abg Industrial Hotspot radios (RLX-IHW-66).
"We use Cat-5 cable and power over Ethernet (PoE) for power supply to the radio and communication between the radio and the PACs. PoE allows us to plug the radios right into our PACs, plus the casing allows them to be mounted outside without weather concerns," adds DiFerdinando. "Landfill-gas-to-energy is not just environmentally responsible, it makes sense financially. The savings we offer our customers can be enough to help companies stay in the United States. Another one of our customers is one of the largest manufacturers of disposable dishware, and they were able to save enough using our natural gas substitute to add a third shift during the week and schedule weekends into production, and those extra shifts mean extra jobs. It's a nice feeling."
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Jim Montague is Control's executive editor