The Challenge

To meet increasing demand for its additives, a global specialty chemicals manufacturer purchased a multi-acre site to build a new state-of-the-art processing facility. They needed a partner to strategically develop a scalable network infrastructure and control system architecture that could support the site now as well as in the future as additional process buildings are added. 

Project Goals

While one of the overarching goals of this new site is to increase the company’s total capacity and eliminate production bottlenecks at the original facility, the company had several additional site goals for this expansion. First, the site buildout was planned as a multiphase, multi-year project that includes construction of five processing buildings, a pilot facility, an administration building/OT data center, a utility building, and a truck loading/unloading building. To avoid rework as additional buildings are constructed, the company needed a scalable control architecture designed and implemented during phase one and a plan for migrating some assets installed in the first production building to their final position. In addition to scalability, the longevity of the base of their control system architecture was also crucial.

Another primary goal for the new processing buildings was to incorporate lessons learned from their original site, which has been in operation for more than 90 years and has seen multiple process automation upgrades and migrations. They wanted a partner who could help with this by evaluating new technologies and incorporating process and automation improvements across their systems. Lastly, they also wanted this new site to serve as a showcase facility.

Overcoming Control, Network, and Communication Challenges 

To develop the site network and control architecture with the organization’s goals in mind, there were a variety of challenges to overcome. First, because the company produces a wide variety of chemistries in small batches, their control architecture needed to be capable of managing both discrete and continuous processes and be flexible as process changes were implemented. For this first process building, this included implementing a mixture of sequences for truck loading and unloading, batch controls for two reactors, and continuous control of the wiped film evaporator (WFE). 

To meet these control needs while ensuring we were future proofing the plant architecture, we selected Siemens SIMATIC PCS neo for the distributed control system (DCS). Selecting PCS neo was a forward-thinking choice as it is the first web-based process control system, which we felt was a huge benefit for this customer because it inherently allows for flexibility in terms of access as well as scalability.

Another key part of our design was that we needed to follow intrinsically safe design standards. Since a hazardous atmosphere may be present during normal operations, we had to develop the system to Class I Div 1 standards, which impacted many of our design decisions as well as hardware selection. For example, we selected SIMATIC ET 200SP HA Ex distributed I/O system because it has built in barriers, an IP20 degree of protection, and can communicate with SIMATIC automation systems via PROFINET. 

With the need to follow Class I Div 1 standards and the wide variety of equipment and processes required in this facility, we needed to leverage our expertise in multiple communication protocols to ensure all systems were properly networked throughout the facility. We used PROFIBUS PA for communication with the analog instruments in the hazardous area since this protocol is specifically designed for process automation with intrinsically safe features. 

Additionally, inherent in the design of PCS neo is a multi-network segregated architecture. This means the PROFINET used for I/O communication is separate from the networks that connects to the operator workstations and the historian. We used MODBUS to communicate with Eaton variable frequency drives (VFDs) and the actuator-sensor interface (AS-i) bus to connect field devices, such as discrete valves, which reduced wiring costs. 

Additionally, we built the network architecture to be future looking, flexible, and secure so that it can report data that employees in both the plant and on the business side of the organization need to see. Figure 1 shows the architecture we designed for the first process building. We also developed a plan for producing the required reporting for hazardous waste for the state department of energy and environmental protection (DEEP). 

In addition to the plant network architecture, we designed the fiber optic cable infrastructure and building-to-building connections that will eventually allow for ongoing operation and engineering of the system as it evolves. This includes critical systems that need to be used site-wide such as security cameras, gas detectors, and fire alarms. Doing this required extra planning and coordination with other users of those networks since these items are run outside the control system. In our design, we recommended that additional cables be used for these systems, but that they could utilize the same conduits.

Achieving Project Goals

As we wrap up phase one of this multiphase project, we are confident that we’ve helped the customer achieve the project goals stated above. Upon completion of this first processing building, the customer will be able to immediately boost production by implementing a parallel production strategy since their plan involves running the most time-consuming step of their process, performing separation using the WFE, at this new facility. This will involve transporting intermediate to this facility to process it in the WFE and then transporting it back to complete the process, or packaging for some products. 

To achieve their site-specific goals, not only did we select a control architecture inherently designed to be future proof, we also made sure moving equipment and making connections to future buildings will be a simple task. While everything we’ve developed to this point is being installed in building 1, it will not live there permanently, and we had to keep that in mind as we were developing these systems. 

Additionally, we designed this facility to eliminate some of the inefficiencies the customer is currently experiencing at their original site with their aging control system that was layered on top of even older manual systems. Finally, to meet the customer’s request to have this first building serve as a showcase facility, we used glass doors on all the control cabinets. 

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