As a result, LY Steel's engineers worked with Schneider Electric's (www.schneider-electric.com) 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 (www.parsec-corp.com) 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 (www.honeywell.com/ps) 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.