Mitsubishi Chemical Connects HART Technology to Control Room Savings up to $20-30,000 a DayPROJECT OBJECTIVES
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SOLUTION
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RESULTS
- Increased peak production to save an estimated $20-30,000 USD per day.
- Detected the onset of plugged lines to prevent a 5-day, $3-million USD shutdown.
- Reduced instrumentation maintenance costs 10% through advanced diagnostics at the pressure transmitter accessed from the control room.
The Mitsubishi Chemical plant in Kashima, Japan, employed HART Communication to access real-time process variables, reduce maintenance costs 10% and averted issues to prevent a $3 million USD shutdown.
Mitsubishi Chemical Corporation has improved its ability to diagnose abnormal process conditions and track equipment health 24 hours a day, thanks to an innovative instrumentation team at the company’s 380,000 ton-a-year ethylene plant inKashima, Japan. “Our goal is to detect abnormal situations in the process and protect field devices from malfunctioning,” says Takayuki Aoyama, team leader of the instrumentation group, at Mitsubishi Chemical. He notes HART Communication’s ability to collect online data from field devices without disturbing the 4-20mA analog signal between the devices and the distributed control system (DCS).
That connection is critical to the plant’s success, he says, because “diagnostic parameters that help detect signs of an abnormal situation or degrading performance are difficult to obtain with simple handheld devices” which require “a time-consuming, manual, step-by-step approach.”
Instead, HART-enabled devices are visible directly from the DCS and asset management applications in the control room and require no manual intervention.
“HART technology made it possible to access the data without manual operation,” Aoyama says. “This made it much easier for us to gather data and opened up many possibilities for us to detect abnormal situations from field devices.” He cites valves, pressure transmitters, and analyzers as high-maintenance devices, while looking forward to additional work with the process intelligence of HART Communication with vortex flowmeters, Coriolis flowmeters, and valve positioners.
“We estimate that cost savings is more than 10 percent due to utilizing HART features in the devices,” adds Aoyama.
So far, the Mitsubishi plant has connected approximately 800 HART-enabled devices to the control room directly. (Ten of these are connected via multiplexer.) The control room features one vendor’s distributed control system (DCS) and integrated asset management system; and a second vendor’s asset management system connected via a multiplexer.
Because the HART Communication Protocol is ubiquitous—all vendors in the control room as well as the field conform to it—Mitsubishi was able to rapidly gain remote access to instrumentation. Differential pressure transmitter data in particular played a key role in the benefits achieved.
Advanced HART diagnostics from the pressure transmitter allowed Aoyama’s team to quickly detect the onset of a plugged impulse line in a naphtha flow application as well as a plugged manifold during start-up. It also allowed the team to measure flow loop variability, which helped identify an area of unstable flow due to inadequate pipe length. Furthermore, HART technology reduced the time and effort of root-cause analysis and provided a more rapid discovery of the problem.
After installing a conditioning orifice plate, flow signal stability was verified. This in turn provided an accurate measurement for improved plant availability and greater throughput.
Additionally, the use of advanced HART diagnostics from the pressure transmitter allowed the team to detect an inefficient compressor pump. The process data provided through HART communication helped personnel isolate and perform repairs to the compressor, preventing damage to the rotor. If not identified and repaired in a timely manner, this problem could have led to a plant shutdown.
While direct operational cost savings haven’t been released, the cost of an unscheduled plant shutdown is estimated to cost $600,000 USD in lost production per day, and minimum production restart time of 5 days. Hence, preventing a shutdown/startup cycle saves a minimum of $3 million USD. To date at least two device failures have been detected that could have caused a plant shutdown.
In addition to downtime-inducing situations and simultaneously reducing maintenance costs more than 10%, HART technology has provided process benefits. These include improved peak production performance, which if maintained, saves an estimated operational savings of $20,000-$30,000 USD per day.
HART Communication has become a standard communication protocol for the plant. Plans call for gradual upgrades to the plant’s remaining 2,200 analog-only devices with HART technology. Additionally, the company is currently testing WirelessHART devices for use in the plant.