Smart automation supports blue and green hydrogen deployments
PLCs and IIoT edge control upgrades equipment used in hydrogen production.
Sustainable clean fuel is increasingly an imperative today. Production is first link in a value chain including storage, transportation and consumption. Each step must be controlled and monitored for safe handling.
Many aspects of hydrogen production are similar to, or more complicated than, hydrocarbon production. Hydrogen production involves equipment, valves, pumps, tanks, and instrumentation. Two hydrogen production methods are steam methane reforming (SMR) and water electrolysis.
As hydrogen production scales up, there’s opportunity to apply automation beyond basic control, including data connectivity and management. In the past, PLCs and HMIs automated equipment, with DCS used for large-scale petrochemical and refinery operations.
In modern hydrogen production, edge control and innovative HMI/SCADA platforms supplant traditional control. Hydrogen producers attain reliability, security and accessibility with newer architecture and edge capabilities. Using hardware and software with built-in Industrial Internet of Things (IIoT) capabilities, designers develop modular, scalable solutions for safe and smart operation every step of hydrogen production and handling (Figure 1).
Going grey, blue, or green
Though hydrogen is abundant on earth it is complicated process to accumulate it in gaseous form. Colors are used to characterize hydrogen production types. The most common production paths are referred to as grey, blue and green.
- Grey hydrogen: Uses non-renewable energy to power steam methane reforming (SMR) equipment, converting natural gas (methane) to hydrogen, but also creating greenhouse gas emissions.
- Blue hydrogen: Follows the same production process as grey hydrogen but uses advanced techniques to capture up to 95% of emitted carbon.
- Green hydrogen: Also called clean hydrogen, uses renewable electricity to power electrolysis, splitting water molecules into two hydrogen and one oxygen atom.
Over 95% of hydrogen produced today is blue or grey hydrogen produced at industrial scale. Green hydrogen is a tiny fraction of production and a good fit for intermittent renewables and localized production. Green hydrogen production is more than ten times more expensive than blue, sometimes even 10 times, but prices continue to drop based on growing efficiency and scale. Blue hydrogen production is here today and a near-term solution to meeting demand, while green production will address increasing demand based on a longer-term vision.
Common to blue and green deployments is the need for effective automation and data connectivity of smaller production skids, not to mention distribution systems, storage networks and refueling stations.
Many SMR designs are adopting an on-site modular approach, and green electrolysis equipment is also well suited for localized and containerized form factors. Another benefit of modular and local installations is that it minimizes hydrogen transportation needs. While some new production facilities are coming online, there is also a need to convert existing grey hydrogen systems to blue by adding equipment and enhancing automation.
Due to the distributed nature of hydrogen production, solutions must address a range of automation requirements, while providing exceptional connectivity. Digital platforms and methods for automating hydrogen production must included:
- Provide reliable deterministic control in harsh field conditions
- Offer options for redundancy
- Be scalable and modular for expanding and converting infrastructure
- Support fast-track designs
- Enable open and interoperable connectivity in the field
- Incorporate native security
- Include cloud connectivity and data management for remote access and detailed analysis.
Designers need PLCs, both compact and high-performance models, with IIoT capabilities to effectively transfer data and inform better decisions. More advanced equipment needs the extra computing capabilities of edge controllers, or even industrial PCs, to execute innovative control schemes and to closely integrate operational technology (OT) field equipment with information technology (IT) to deliver best performance.
It is important to consider whether an automation partner offers a breadth of complementary elements such as safety devices, instrumentation, analyzers, and valves — especially as each of these items becomes more intelligent and readily networked with control platforms (Figure 2). Availability of asset management system, maintenance and support services ensures investment protection.
A solution provides a single point of support for digital automation infrastructure, developing automated hydrogen production equipment in the most agile manner possible and further enabling their OEM and SI vendors to execute requirements more easily.
Hydrogen production challenges
Advanced automation does more than just turn pumps on/off or stroke valves open/closed at the right times. Modern systems must deliver advanced monitoring and predictive analytics. Here are a few hydrogen-specific cases.
Corrosion monitoring: Hydrogen production skids can be subject to product streams with excessive corrosion-causing sulfur. Modern PLC controls must connect to analytical instruments to enable real-time gas purity analysis, detect problematic conditions, advise operators, and even automatically add inhibitors to improve plant safety by maintaining equipment integrity. Advanced corrosion detection instruments can be integrated to track equipment degradation (Figure 3).
SMR optimization: Operators want to run SMRs at the maximum possible efficiency, but overly aggressive steam firing leads to unacceptable pressure increases, equipment failure, and even personnel injuries. Edge controllers go beyond basic PLC automation by performing advanced calculations with local and external data to determine the optimum operating setpoints within safe boundaries, and to ramp steam injection up or down to avoid unplanned disruptions.
Leak prevention: Hydrogen leaks represent an extreme hazard anywhere, but especially so at storage units. It is extremely important to integrate instrumentation and remote I/O with automation to detect leaks and command the systems to a safe state. With the right measurement technologies, it is possible to monitor hydrogen tank lining conditions, thus avoiding leaks.
Fueling stations: Fueling station are widely distributed. However, they have many of the same needs for automation and condition monitoring as hydrogen production equipment, plus they need to work autonomously, while interacting with supervisory systems for commercial reasons. IIoT-capable PLCs provide a cost-effective and right-sized solution to control smaller local installations, while integrating IT-friendly data connectivity.
Safe, smart hydrogen production
Hydrogen production plays an increasingly important role for the world’s clean energy needs. In the short term, existing large-scale grey hydrogen production needs to be upgraded and converted to blue methods, and modular blue production systems will be developed and deployed where needed. Broadly speaking, more green hydrogen production at the point-of-use is the ultimate goal but advances in technology must be applied to make this approach cost-effective.