Golden Triangle Energy Cooperative Replaces Outdated DCS in Favor of PlantPAx Process Automation System from Rockwell Automation
Ethanol producer cuts costs and downtime while improving throughput thanks to patented process application
PlantPAx Process Automation System
Services and support
- The solution, based on the Logix Control Platform with a Control Logix PAC, replaced an outdated DCS and provides a highly reliable, flexible process control system
- New I/O platform eases system upgrades
- The FactoryTalk View SE software provides customized operator interface for easier transition to new control system
- Ethernet communications provide remote monitoring and troubleshooting
- Readily available spare parts and training support keep costs and downtime to a minimum
Reduced spare part needs and costs
- Flexible and easily expandable PlantPAx system helps GTEC increase production capacity by 75 percent
- The PlantPAx system needs only one-third the number of spare parts compared to the old control system components, saving the company 66 percent in reduced inventory costs
- Customizable HMI software makes system transition easier for operators
- System reliability has led to a significant reduction in downtime and reduces the risk of unexpected emergency shutdowns
- Remote-monitoring capabilities reduce travel time and corresponding emissions
Golden Triangle Energy Cooperative produces approximately 20 million gallons of ethanol each year
Most people think of ethanol as an alternative fuel designed only for specialized flexible fuel vehicles (FFVs). While this is partly true – the more than six million FFVs on the road today are designed to run on E85, a blend of 85 percent ethanol and 15 percent unleaded gasoline – in reality, ethanol is a much more commonly used product. E10, a blend of 10 percent ethanol and 90 percent unleaded gasoline, can be used to power any make or model of car sold in the United States. In fact, almost 70 percent of the gasoline sold in America contains some amount of ethanol.
And ethanol isn’t just for cars. Industrial ethanol is used in everything from mouthwash to hand sanitizers to perfume and shampoo. Pure beverage ethanol, manufactured in the form of grain neutral spirits (GNS), is used in many premium alcohols, such as vodka and hard lemonades. Because ethanol is produced from renewable resources – typically corn – it can be grown domestically here in the United States, helping reduce our dependence on foreign oil.
Most ethanol production facilities, such as Golden Triangle Energy Cooperative (GTEC) in Craig, Mo., generate little to no waste throughout the manufacturing process. “Everything we consume at the plant is either sold or reused,” said Roger Hill, general manager, Golden Triangle Energy Cooperative. “Between the ethanol we produce and the livestock feed we sell as a byproduct of the ethanol manufacturing process, nothing at the plant goes to waste.”
With $50 million in gross annual revenue, GTEC operates on a continuous basis, manufacturing approximately 20 million gallons of ethanol and over 160,000 tons of wet livestock feed every year. The entire production process is run by just three operators, and until a few years ago, controlled using a distributed control system (DCS) that was installed when the plant was built in 2001. However, just a few years after the plant opened, Hill and his colleagues were informed by the DCS manufacturer that their system was obsolete, and the company would no longer be manufacturing replacement parts.
“The company would still repair some of the rundown parts, but the refurbishment process could take up to three weeks,” explained Hill. “One day of downtime at our facility can cost us $35,000 in lost profit, and unexpected shutdowns can cause unsafe conditions for our employees. We started shutting down operations at every threat of a thunderstorm just to avoid the risk of an outage. We were even browsing online auction sites to find backups for our critical components.”
The GTEC employees also were fed up with the limited service offerings from their DCS provider. “A few years back, our maintenance staff called the manufacturer to inquire about some difficulties they were experiencing with the system,” said Hill. “We were told that the service provider was going to a movie and would call when he was finished.” With downtime costing almost $1,500 an hour, that was an expensive movie for GTEC.
Hill and his colleagues made the decision to start shopping for a new control system, but first they had to justify the cost of a complete system upgrade to their board of directors. “They were confused as to why a system installed just five years earlier already needed to be replaced,” said Hill. “From their point of view, the plant was still running at full capacity. But I explained to them that the lack of replacement parts and reliable service would eventually cause us to completely shut down. That was a risk we simply couldn’t afford to take.”
With the board of directors’ approval, Hill and his staff started their search. “We needed a reliable system with readily accessible spare parts, and extensive support and training capabilities,” explained Hill. “We also were planning to expand production in the near future, so we wanted a flexible system that would allow for easy upgrades and line expansions.”
To help facilitate the search and make sure the new control system met all of their requirements, GTEC contracted with Bachelor Controls Inc. (BCI) of Sabetha, Kan., a Rockwell Automation Solution Provider. Rockwell Automation Solution Providers are best-in-class systems integrators who provide industry and applications expertise in delivering automation and information solutions to manufacturing companies globally.
“It was important that we help GTEC select a system that would provide ongoing support for Roger and his staff, regardless of whether BCI was involved in the future,” explained Marvin Coker, senior project engineer, BCI. “Rockwell Automation provided the highly flexible system, service, training and locally available parts that GTEC needed. Other systems we looked at just didn’t have the level of hardware and software support that we wanted.”
With the flexible and easily scalable PlantPAx Process Automation System, GTEC was
able to install a new production system that expands production capacity by 75 percent –
without having to hire any new staff.
Coker and the engineering staff at BCI selected the Rockwell Automation PlantPAx™ Process Automation System to replace the existing DCS. The PlantPAx system is based on the Rockwell Automation Integrated Architecture™ platform, which delivers a unified process, discrete and information solution. At the heart of this system are Allen-Bradley® ControlLogix® programmable automation controllers (PACs) from Rockwell Automation, which leverage common development tools, network protocol and a service-oriented architecture.
Prior to the actual installation, engineers from BCI and GTEC met several times to compare piping and instrumentation diagrams against the actual layout at the facility, check each I/O point, and discuss the overall control strategy. In order to keep costs down and minimize complications during the installation, it was decided that all the existing field wiring and devices would be retained during the upgrade. The logic for the new system was also reverse engineered from text pulled out of the outdated DCS, retaining the same control strategies. “The BCI team made every effort to keep production disruptions to a minimum,” said Hill.
The phased migration from the outdated DCS to the PlantPAx system was completed in two stages during consecutive scheduled shutdowns, which would usually last four days. During the pilot phase of the PlantPAx system installation, BCI decided to focus on the grains receiving area. “The receiving area was a little bit more out of the way, so if there were any issues, it would be easier to catch and have less of an impact on the overall production process,” explained Coker.
Phase one, though it was a smaller project, included the installation of one of the ControlLogix controllers, Ethernet and ControlNet communications infrastructure, and FactoryTalk® View Supervisory Edition (SE) human-machine interface software. “It was important that the operator interface look similar to the interface from the old DCS,” explained Coker. “We were able to customize the FactoryTalk View SE software to mimic the look and feel of the old interfaces, which made it much easier for the operators to adjust to the new system.”
The second phase – which was much larger and involved the complete plant switchover to the new system– took just over four days. BCI replaced the outdated I/O racks with I/O from Rockwell Automation for the more than 800 I/O points spread throughout the plant. The team installed the remaining ControlLogix PACs and checked that each I/O point responded correctly to commands from the controller. Restart procedures began on the morning of the fifth day, and with a nearly flawless installation process, the plant was running at full production capacity by the end of the day.
Hill and his colleagues at GTEC are thrilled with the PlantPAx system. “Downtime has been dramatically reduced – there are some months that we operate with zero downtime,” said Hill. “Maintenance time also has been significantly reduced – mostly because we don’t have to do much maintenance!” For their occasional service needs, BCI engineers can utilize the remote connectivity allowed by the Rockwell Automation open architecture, which provides remote access to the GTEC system over a simple Ethernet connection. This reduces their travel time to and from the plant keeping downtime, emissions and customer costs to a minimum.
Trolling online auction sites for replacement parts is a thing of the past, as well. “Following the control system upgrade, I was thrilled to learn that the recommended spare parts list for the Rockwell Automation hardware was only a third of the old control system components, both in terms of the number of items and the cost for those items,” said Mike Pickard, maintenance manager, GTEC.
Thanks to the flexibility and easily scalable nature of the PlantPAx system, GTEC was able to recently install a new production system to produce the grain neutral spirits used in alcoholic beverages. “The installation of the new line was incredibly simple with the PlantPAx system,” said Coker. “We just tied in the new I/O, downloaded the necessary programming to the FactoryTalk View SE software and ControlLogix controllers, and doublechecked the I/O points for each valve and input. The operators were already comfortable with the system, and the software made it easy to get production started right away.”
With the new high-quality line up and running, GTEC has expanded production capacity by 75 percent.
It is now able to manufacture 35 million gallons of industrial and beverage-quality ethanol each year, which helps position the company to capitalize on the increased interest in alternative fuels worldwide. With the PlantPAx system controlling the operation, GTEC is able to operate the entire plant – including the new high-quality process – without hiring any new staff.
“Our return on investment on the new system has been tremendous,” said Hill. “When you operate 24 hours per day, there is no opportunity to make up for profits lost as a result of downtime. Thanks to the new PlantPAx system and the support of BCI, we don’t have to play catch-up anymore.”
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