Automation technology plays a crucial role in environmental sustainability
A range of pressures are forcing industrial organisations to make a strategic shift in environmental sustainability. Manufacturers must reduce greenhouse gas (GHG) emissions and comply with tighter environmental legislation or risk exposure to litigation on compliance failure. Both activist and institutional investors are driving low-carbon economic strategies and greater risk aversion, while social pressure from consumers with enlightened environmental awareness has never been greater.
As a result, ever more industrial companies are committing to ambitious decarbonisation and environmental sustainability strategies. Energy source decarbonisation through greater use of low carbon power sources and fuels will be fundamental, but all power generation, heavy industries and manufacturers will have a significant role to play. This will require increased carbon capture utilisation and storage, electrification, energy supply optimisation, energy storage, energy efficiency and optimisation, and improved waste management. Automation technology will be crucial to achieving these targets.
Transitioning from a fossil fuels to a sustainable-based energy system and achieving decarbonisation targets is not straightforward and requires considerable investment. Although fossil fuels will still dominate the global energy landscape for some time, for high-emitting sectors it is essential to have alternative low-carbon energy, including biofuels and green hydrogen, available at the right time for key investment decisions. Hydrogen is rapidly emerging as the fuel of the future because it offers a high calorific value and energy density, multiple transport and storage methods, and most importantly, virtually no GHG emissions when combusted with oxygen. As the world transitions away from traditional grey or brown hydrogen production, blue hydrogen will be an important contributor towards decarbonisation, especially in parts of the world with an abundant natural gas resource. Within refineries, hydrogen will most likely transition from existing production methods to a steam methane reformer followed by post-combustion carbon capture.
New infrastructure is required to meet this increased demand, including large-scale electrolysis production using renewable or low carbon energy sources. Providers of electrolysis technology are looking at ways to scale up and improve their designs, which will need to handle higher current density and provide high efficiency over a longer lifetime. Technology providers also need to make their designs ready for production-chain manufacturing, which will lower the cost per kilogramme of hydrogen.
Control and operational strategies for plants are very important. Operational setpoints need to be established and balance-of-plant components and sub-systems must be developed, integrated and optimised. To this end, one solution that is proving to be a game-changer is digital twin technology.
A digital twin is a software-based virtual replica of the complete physical assets of a production facility, including its process equipment, instrumentation and controls, as well as the production processes. Through this replica, the operation of these assets is modelled and simulated through their lifecycles. A typical digital twin will usually represent a replica of the control system, operator displays and alarms, along with process modelling and a real-time execution and integration solution for the automation systems. Digital twins are developed using process design information, including piping and instrumentation diagrams, process flow diagrams and other data governing the process. This information is then converted and developed into a software-based representation of the process using simulation software. As this software has a wide range of unit objects pre-configured, models can be developed efficiently to provide a highly accurate representation of the behaviour and dynamics of the process under consideration. The digital twin becomes an invaluable tool to analyse various ‘what if’ design scenarios, such as different rectifiers or water purification systems, different balance-of-plant design improvement ideas and others. A digital twin can also validate the optimised control and safety schemes, including advanced control models and start/stop procedures.
When the plant is operational, the digital twin can provide data and insight into equipment and system health, helping plant management to optimise preventative maintenance practices and avoid costly unscheduled downtime. The accuracy of the digital twin can be constantly enhanced with data taken directly from the process as it becomes available. With many hydrogen electrolysis projects to be built in phases, this enables the digital twin to facilitate seamless integration of each phase.
Electrification and system integration
Electrification is critical for decarbonisation. With power generation companies significantly reducing their GHG emissions, attention is turning to electrification of end uses to take advantage of both the increasing share of renewable energy and the higher efficiency of electricity-based technologies. This will require the expansion of electricity transmission and distribution networks, and new ‘end-use’ technologies for things like process heating.
For example, Emerson is currently collaborating with Hydro Quebec, a large power utility in eastern Canada, on a solution that combines our industrial compressors with our measurement and control expertise, to provide new, sustainable heat pump technology. The heat pump will deliver large capacity heating, cooling and hot water to commercial buildings, with Hydro Quebec providing power from renewable sources. Ultimately, this technology will be deployed to buildings and will help infrastructure owners to decrease operational energy costs as well as reduce carbon emissions.
Automation providers such as Emerson are also helping to transform and digitise operations to more seamlessly incorporate renewable energy sources and improve energy efficiency and reliability. Emerson’s operations technology software helps provide generation, transmission, distribution and outage management by enabling real-time monitoring, control and resource optimisation across the power enterprise. An example of this is MainPower New Zealand selecting Emerson to supply a new advanced distribution management system that will enable a more reliable, resilient, flexible and efficient electricity distribution network.
Automation technologies also help the efficient and reliable operation of microgrids, which provide self-sufficient energy production and distribution that can incorporate diverse sources of electricity, including solar power, wind power, hydrogen power and advanced storage battery technology. A microgrid can act as an ‘island’ operation, connecting and disconnecting from the larger distribution grid to satisfy its power needs. Should a weather or other emergency event disrupt grid operation, the microgrid can safely disconnect and operate autonomously.
Emerson’s Ovation™ Distributed Control System helps ensure efficient and reliable operation of the microgrid, providing the operator with a concise view of all generating assets and implementing the optimal way to meet energy demands while reducing environmental impact. The Ovation system manages internal microgrid operations, including solar photovoltaic and thermal rooftop systems, wind turbines and battery storage systems, and interfaces to systems controlling the microgrid’s connection to the main electrical grid.
Emissions monitoring and control
Emissions typically come from boilers, gas turbines, diesel engines and flaring, but also through continuous process media leakage from pipelines, tanks or devices. Within process industries, one of the biggest opportunities to increase energy efficiency and reduce emissions is by improving combustion control of fired heaters and boilers. Because of process control variability, fuel gas composition variability and safety risks, the equipment operates with a high level of excess air. While the excess air ensures complete combustion and maintains a safer operating margin, the trade-off is excess NOx emissions and higher fuel and energy costs. Combustion measurement solutions help to optimise combustion control by minimising fuel and excess air requirements. This can result in greater fuel efficiency, reduced GHG emissions and significant operational savings.
Methane is one of the most potent GHGs and a large contributor towards global climate change. Methane is the primary component of natural gas and is emitted to the atmosphere during the production, processing, storage, transmission and distribution of natural gas and crude oil. Methane emissions can be broadly classified into two categories – emissions caused by day-to-day operations, and emissions caused by equipment fugitives (leaks).
Fugitive emissions typically come from pumps, valves, connectors, compressors and pressure relief devices. Worn or damaged seals, valve packing, O-rings and disks can all lead to leaks. These leaks, which are due to incorrect sizing, configuration, installation and maintenance, can be very difficult to detect due to ambient conditions and large areas to monitor relatively small quantities, but when aggregated become the greatest contributors to overall emissions. Without regular monitoring or inspection, these leaks can often go undetected over time until they become problematic or even dangerous.
Accurate tracking and reporting of emissions data are requisite first steps in achieving mandated reductions. Establishing problematic equipment and then performing remedial actions will lead to improved performance. Smart technology, such as intelligent valve positioners and acoustic wireless sensors, enables monitoring and reporting of short duration upsets that can lead to small and/or unnoticed emissions. Plantwide networks supporting device diagnostics and condition monitoring can not only help to identify issues earlier, but also reduce emissions.
Flaring by upstream oil and gas operators has been a large contributor to fugitive emissions. In today’s environment, many operators are either processing the gas or using it for reinjection into the reservoir, but flaring is still widely used to provide a vent system to avoid pressure build-up in the process. Protection against pressure build-up is mainly provided by conventional pressure relief and blow down valves that will discharge gases and liquids to the flare when process design pressures are exceeded. High-integrity pressure protection systems (HIPPS) can help operators reduce fugitive emissions resulting from pressure protection. HIPPS form part of a safety instrumented system (SIS) and are designed to prevent overpressure by shutting off the source and capturing the pressure in the upstream side of the system, thus providing a barrier between the high pressure and low pressure sides of the process plant. The tight shut-off prevents loss of containment and eliminates fugitive emissions.
Organisations can start developing a strong flare management plan by employing wireless pressure relief valve (PRV) monitoring solutions that can quickly identify the source of release in their flare systems, as well as deliver information needed for compliance. Plus, efficient gas analyser technologies that add a fast, one-minute BTU measurement for precise control of flares, enable refineries to easily comply with new regulations that tighten the monitoring frequency of flare vent gas components.
Gas flaring can be exacerbated by non-routine flaring caused by the poor reliability of devices such as control valves or compressors. To prevent this, organisations can implement predictive maintenance strategies and condition monitoring solutions that prevent unexpected failures. Increasing vibration can indicate blade, bearing, shaft or coupling issues that can lead to compressor failure and a potential unit shutdown. Online compressor health monitoring solutions provide early warning alerts of excessive vibration and bearing wear, allowing technicians to perform scheduled repairs or adjustments that can prevent unexpected downtime that leads to excessive flaring.
These solutions are enabled by wireless sensors and networks that instantly interpret key asset health data, with pre-built analytics giving operators the information they need to make faster and better-informed decisions. Similarly, tools such as Emerson’s Plantweb™ Insight industrial analytics solution, help to eliminate the guesswork for PRV monitoring. This application provides an indication of PRV releases, including start and end time and production and emissions loss. This continuous monitoring can reduce unplanned shutdowns that impact production, minimise emergency flaring and reduce emissions.
The Plantweb Insight Steam Trap application determines the online health status of steam traps, helping to reduce loss steam and energy waste, whilst the heat exchanger application provides in-depth monitoring of shell and tube heat exchangers by analysing plant sensor data and delivering predictive diagnostics that help operators maintain optimum performance and energy efficiency.
These analytics tools extend to pipework corrosion and erosion monitoring, with non-intrusive online applications monitoring metal thickness, which is a major factor in determining the heath of piping. Changes can be detected in minutes, enabling corrective actions to be performed before damage occurs that otherwise would impact the health of the asset and create the possibility of emissions due to leaks.
Earlier detection of leaks is another area where significant improvements can be made. Because of the large physical footprint of many processing plants, this presents constant challenges for detecting gas leaks and fugitive emissions. Experts can help by discovering problem areas and suggesting solutions to better control and reduce emissions. With access to a complete line of automated solutions and resources that eliminate the root causes of emissions, organisations can launch a customised emissions control programme and know that their plant will meet environmental regulations.
Advanced technologies are available to provide accurate flow rate measurement and optimised computational pipeline monitoring to ensure pipeline reliability. Ultrasonic gas leak detection devices enable the rapid detection of gas leaks in high pressure processes, such as pipeline monitoring or gas compressor stations. These innovative solutions use acoustic sensors to identify fluctuations in noise that are imperceptible to human hearing within a process environment. Unlike traditional gas detectors that measure accumulated gas, ultrasonic gas detectors ‘hear’ the leak, triggering an early warning system. These solutions provide rapid detection response times and can be applied to air cooled heat exchangers, compressor stations, generators, gas metering skids, well bay areas and separators.
Energy efficiency and optimisation
Improving energy efficiency and reducing consumption and subsequent emissions is another key focus of process industries. Major energy efficiency improvements can be achieved for a low initial cost by optimising the performance of process control loops. Control schemes are generally designed to keep the process stable and minimise variability, but in many cases this does not happen. In a typical plant, almost two-thirds of control loops are underperforming, for reasons such as poor valve performance, incorrect loop tuning and inappropriate control strategy. As a result, huge amounts of energy are wasted.
Poor tuning leads to greater process variability. In turn, this leads operators to run the plant away from the most efficient regions, which are typically close to operating constraints, such as quality limits, to allow for a greater margin of error. Despite this, many facilities do not have a formal, consistent approach to troubleshooting, and the root causes of issues can therefore go undetected for weeks, months or even years.
Emerson is addressing this issue by providing a range of tools and services that can help achieve significantly better control performance. Among these is the DeltaV™ Loop Service, which is designed to optimise system reliability and performance. The performance of every control loop is measured and a control performance score indicates how many control loops have limited control, high variability, uncertain inputs, or are not in the normal operating mode. Control performance experts, working remotely, provide monthly reviews of control performance, identify issues, make recommendations for corrective actions and establish a control performance roadmap with prioritisation as to the control loops that have the greatest impact on the bottom line. This aims to maximise the number of automatic and well-performing control loops, leading to greater product quality and throughput, fewer operator interventions on-site, and increased energy efficiency.
Where there are issues that require more than PID (proportional integral derivative) control, Emerson provides advanced control technologies that automatically account for process interactions and difficult process dynamics, and easily handle issues such as excessive deadtime and loop interactions. Employing these advanced control techniques improves product quality by dramatically reducing key process variabilities, increases profitability by operating closer to process constraints and limits, and further increases energy efficiency.
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