Smart Refineries - A Move into the Future
Chidambaram Subramanian
Officer Grade A
(Metallurgy & Inspection)
Inspection Department

Smart automation systems in refineries provide immense advantages over conventional automation, which is used only for operational control and safety of the processing units. The article will focus primarily on the need for smarter systems in today's refinery industry. It will give an insight into some valuable smart features and their benefits, including enhanced production and efficiency.

With continuous technological advances and increased emphasis on digitalization and the Industrial Internet of Things (IIoT), the nature of automation systems is changing very fast. The article will also address future trends in smart automation that could prove beneficial to the refining industry.

Engineering organizations play a vital role in the concept finalization, selection and engineering of such systems in refineries. It is critical that they remain updated on the latest developments in order to suggest the best and most future-ready options to their clients.

The Need of the Hour

The evolution of smart instrumentation changed the concept of automation in the process industry decades ago. With continuously increasing market competition, refineries find it extremely necessary to make refinery automation smarter and take it to the next level of technical superiority. Smarter refineries are no longer a vision of the future but the need of the hour.

What is 'Smart'?
Conventional automation systems in refineries consist of basic process control systems (BPCS) and safety instrumented systems (SIS). They handle the control, monitoring and safety of refinery processes. The BPCS acts as the first layer of protection and takes care of all monitoring and control of process parameters. If the BPCS is not able to control process behavior, SIS shifts the process to safe mode by initiating and executing shutdown actions.

Nowadays the expectations from smarter automation systems are not limited to control, monitoring and safety of the plant. A combination of smart engineering, smart operations and smart maintenance make the operation of new refineries significantly safer and more efficient.

Advantages of Being 'Smart'

Employing a state of the art smart instrumentation and automation system is critical in making the refining industry safe, reliable, profitable, predictable and environmentally friendly. Smart instrumentation and automation systems add features like increased diagnostic data, increased predictive maintenance capabilities, operational ease and flexibility to control the process, reduced commissioning time, ease in troubleshooting and many more. They also offer immense operational advantages like maximizing refinery production, minimizing downtime, enhancing efficiency and improving energy management.

Maximizing Refinery Production

Maximizing throughput is always the ultimate goal of all refinery operations . Needless to say, smarter automation helps in bringing down wastes in the processes, predicting production profiles and stabilizing production. Smart systems help operators in performing many advanced calculations easily, enabling the fine tuning and early stabilization of processes.

Minimizing Downtime

Smart instrumentation and automation systems play a very important role in reducing unscheduled production downtime.

The failure of rotating equipment like pumps, motors, and compressors can severely affect plant production. To prevent this, there has been a paradigm shift away from reactive maintenance and towards predictive maintenance.

Advanced smart sensors and instrumentation and health monitoring systems for large machines are considered as key factors in deciding predictive maintenance requirement, thereby reducing the probability of an unexpected shutdown.

Enhancing Efficiency

Efficiency in refinery processes is nothing but maximizing the gain in the process while continuing with the same input conditions. Many smart applications in automation systems help operators in enhancing efficiency. The most critical is the use of advanced process control(APC), which is deployed over basic process control to improve efficiency.

APCs help operators to operate the process or equipment close to its controllable limit, thereby increasing throughput. They enable the efficient handling of process disturbances, increased understanding of process dynamics, and prediction of process behavior. There are many complex process units like reformers, crackers and cokers, where optimizing control manually based on the operator's knowledge and experience becomes challenging. In such complex situations, adopting APCs can significantly improve efficiency .

The most commonly used APC technique is multi-variable control, which uses predictive control based on process dynamic models to improve output. Efficiency enhancement using such APCs has now become an inherent feature of most of smart automation systems.

Energy Management

Enhancing energy efficiency is another important advantage offered by smart automation systems which has a direct impact on profitability.

Energy is one of the biggest expenses in a refinery, often constituting up to 40 percent of the running cost. Smart process designs compounded with smart automation systems help in conserving energy, reusing energy or utilizing waste to generate energy. Some examples of such methods include utilizing flue gases, utilizing the enormous heat generated by exothermic reactions for steam generation and power generation.

Smart Applications in Automation Systems

Continuous research and development in automation has resulted in developing many smart applications and tools. This has enabled the refinery industry to convert the benefits mentioned above to reality. While there are a number of applications that can make systems smarter, a few important ones are explained below.

Alarm Management Systems

Alarm management forms an important layer of protection between the BPCS layer and the emergency shutdown system (ESD) layer wherein process upsets are managed by refinery operators to prevent the process being safely shut down by the ESD systems. Better alarm management puts less stress on the ESD system.

It is often said that it is very easy to add alarms during process or safety reviews, but extremely difficult to manage them in control rooms. This is because alarm flooding, where more alarms go off than a human operator can effectively respond to, can happen in no time. In this situation, operators find it almost impossible to decide priorities and subsequent actions to control the behavior of processes in the refinery.

It is in situations like this that alarm rationalization and alarm priorities become critical. Alarm management is actually an application of human factor engineering in automation systems. It enables operators to handle abnormalities in an effective way so that plant shutdowns and equipment damage are reduced.

Advance Process Control (APC)

In the past, APCs in refinery units used to be a costly affair, complicated and difficult to maintain. As a result, many such systems were turned off within a few years of commissioning. With technological advances, APC tools are now available at a competitive price and are operator friendly with no additional hardware and software. APC applications enable many features like multi-variable predictive control, optimized tuning of proportional–integral–derivative(PID) controllers and dynamic feed forward control which help in enhancing efficiency. Increased production due to efficiency improvement and enhanced operational excellence are the main benefits of using smart applications like APCs in a refinery.

OPC (Object Linking and Embedding for Process Control)

Open platform communication has become one of the most important smart features in refinery automation systems. It entails the real-time communication of plant data between systems of different manufacturers. Although refinery processing units have one common automation system, there are several large mechanical packages which require independent systems. Operators can monitor all the plant data better through a centralized automation control system. This integration of discrete automation systems with the main system is often done through OPC technology. This smart feature enables the integration of alarms and events from the control systems of different packages into the main refinery automation system without significant engineering effort.

Inventory Management

Effective inventory management cannot happen without a smart automation system. Most of the leading automation system manufacturers, therefore, have developed specialized tools and smart applications for tank farm management systems and terminal automation systems.

Refinery managers are dependent on reliable, accurate, real-time inventory information. Smart inventory management systems can accurately detect the deviation between actual production and exported material, which can have a significant economic impact. Intelligent inventory management systems also offer other advantages like tank inventory calculations and the status of loading/unloading pumps and valves.

The huge inventory of hazardous and flammable products in refineries can also pose a threat in terms of human safety, asset loss and environmental damage. Hence smart, reliable and accurate inventory management becomes a necessity in refinery operations.

Future Trends in Smarter Refineries Smart Wireless Instrumentation

Smart wireless instrumentation is not a new technique in the refinery industry. However the use of wireless instrumentation is currently limited to the monitoring of non-critical parameters. With the fast changes in technological developments, we can expect to see rapid growth in the use of smart wireless instrumentation even for control applications. Going forward, wireless instrumentation will constitute a large section of refinery systems .

IIoT in Refineries

In many industries, the investment in Industrial Internet of Things (IIoT) is growing exponentially, and refinery automation is no exception. An enormous volume of data is generated by smart instruments and smart automation systems in refineries. This is collated, visualized and analyzed for overall operational benefits.

Since the late 90s, the number of hardwired input/outputs (I/Os) in a refinery has approximately doubled, which gives an idea of the growth in the quantum of instrumentation as well. The growth in I/Os is predicted to be close to another 100% in the next decade. This shows the immense importance of techniques of data handling and analysis tools in refineries. With the decreasing cost of networking, connectivity and data storage, IIoT will play an important role in future refinery operations.

The advantages of IIoT in a refinery are countless, and include increased profitability, agile process control and a reduction in operating cost and reduced downtime.

Increased usage of IIoT may facilitate the use of smart phones and tablets by refinery operators in future. Cloud technology can be used which requires only a browser and internet access to connect from offsite or to share information. However, it is critical to note that cyber security may pose a hurdle in setting up such innovative smarter refineries. There are hardly any known standards for cyber security in refineries, but with an increased use of IIoT, it will become an inevitable part of successful refinery operation.

Role of Engineering Companies in Implementing Smart Refineries

Engineering companies play an important role in implementing a smart refinery during the basic and detailed engineering phases, which form the foundation of a refinery's lifecycle.

In consultation with all stakeholders, engineering companies are responsible for defining the concepts of smart instrumentation and smart automation systems for the refinery under development. The company outlines the project definition, design basis and smart features of the automation system in the first phase. This is in alignment with the client's expectation and taking into consideration recent industry trends to maximize the benefits of the latest technological developments. These concepts are further developed and implemented in the engineering phase.

In the engineering phase, engineering companies conventionally manage the complete procurement lifecycle of smart automation systems, including requisitioning, technical bid evaluations and vendor drawing review. They generate all engineering deliverables which form the basis for implementation of Smart Automation systems throughout the project. Conducting studies and workshops for alarm rationalization and defining alarm priorities for implementation in the automation system also falls under the scope of the engineering company.

Aker Solutions has recently executed complex refinery units such as a crude distillation unit, sulfur recovery unit and vapor recovery unit, as well as polymers and olefins projects, which use smart instrumentation and smart automation systems. Various smart features like APC, alarm management, inventory control, energy efficiency and OPC were specified and implemented in the engineering phase.

For a few projects, wireless instrumentation was selected for pump seals, vibration monitoring and for monitoring process parameters like pressure, temperature, flow on all lines at the battery limits of process units. This significantly increased diagnostic capability while reducing the cost.

Machine monitoring systems (MMS) were implemented on many projects to determine the health of big rotating machinery.

Another smart feature used on the projects is the use of two out of three (2oo3) initiators for safety systems like ESD. This system, which requires input from two out of three sensors, was implemented as a philosophy on many projects. This ensures increased reliability of the safety system and helps avoid spurious trips which can cause production loss. Such engineering efforts are the backbone of smart refining operations for later phases of a refinery lifecycle.

It must be acknowledged that smarter instrumentation and automation systems are the need of the hour and will be increasingly integral to refinery operations. With significant advances in technology on an almost daily basis , smarter and more sophisticated systems will be developed to make refineries safer, more profitable, more predictable and more environmentally friendly.