Key points
The global warming crisis – and our response to it – are fast approaching a tipping point. Where we are and how we got here are perhaps best summed up by a single number — the total gross weight of greenhouse gases (GHG), including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases (F-gases), measured in metric tons (mt), released into the environment annually. Since 1970 that figure has increased by 145% to a record high of 36.7 billion mt in 20191, which is roughly equivalent to the collective mass of every manmade object on Earth at the start of the 20th century, or about 360 times the weight of the Great Wall of China, all emitted in a single year.2 Not until the Covid-19 pandemic hit in 2020 did GHG emissions in the United States fall below 6 billion mt for the first time in 30 years.3
Most environmental, social and governmental (ESG) initiatives today are based on achieving net-zero emissions, or the equivalent of carbon-neutral operations, by the year 2050, which is the timeframe set by the 2015 Paris Climate Accords. Technological challenges, geopolitical conflicts, disease, natural disasters, supply chain breakdowns, and not least of all finding agreement among global governments and regulatory agencies, many of whose political and economic agendas seemed irreconcilable not long ago, has meant that real progress toward the 2050 goal has come in fits and starts, at least so far.
Unlike other paradigm shifts in the past, however, the incentive for transitioning from fossil fuels to a green economy goes far beyond the usual business, social and legal concerns. Such an undertaking, with the scientific advancement and agreement required among leaders of industry and government about how to best to tackle the issue, will almost certainly look and feel different than technological revolutions in the past. The transition to sustainability will be gradual, and the world’s primary energy sources will still come from fossil fuels for the foreseeable future, but there are without question unprecedented and uniquely powerful forces of solidarity and urgency driving innovation today.
The public and private sectors have recognised not only the ethical and existential imperatives, but also the opportunity to transform global commerce for the better, encouraging research and development, spurring investment, and creating millions of skilled-labor jobs. In 2021, almost 81% of new energy capacity expansion around the world came from renewable sources, a sharp increase over the previous 20-year rate, and an indicator that investing in green technology isn’t just feasible but practically mandatory to maintain a competitive advantage.4
Why Hydrogen, Why Now?
For the past 15 years the renewable energy discussion has centered mostly on photovoltaic solar panel and wind turbine technologies, but as solar and wind have developed into more cost-effective and globally available sources of power, another alternative has come to the forefront: hydrogen (H2). Elemental hydrogen, in gaseous or liquid form, has the highest energy content by weight of all known fuels—three times greater than gasoline—and is a critical feedstock for the ammonia, steel, and cement industries.
So why hydrogen and why now? Hydrogen fuel cells and H2 combustion-based technologies could virtually eliminate all GHG emissions in transportation, stationary power and portable power applications, and hydrogen can store practically limitless gigawatt hours of energy as a ‘responsive load’ on the power grid, improving stability and increasing the efficiency of nuclear, coal, natural gas, and renewable sources. Perhaps most importantly, hydrogen is extremely fungible, flexible, and easily synthesised into different forms. It’s due to this versatility that renewable hydrogen could potentially reduce global GHG emissions by 25% if produced at scale.5
Indeed, scale, along with cost, is ultimately what hydrogen’s market viability as a renewable fuel and global commodity depends on. Hydrogen is the most abundant element in the universe but is rarely found in its pure form on Earth, so it must be manufactured either by separating it from oxygen in water molecules using electrolysis in the case of so-called renewable or “green” H2, or by refining it from fossil fuel feedstocks such as coal or natural gas and using carbon capture utilisation and storage (CCUS) technology to create decarbonised, or “blue,” hydrogen.
Demand for hydrogen has increased 28% over the last decade, to the point where about 70 million mt are currently produced each year, compared to 4.1 billion mt of oil and gas.6 Almost all of that output, 99.6%, is in the form of H2 processed from fossil-based feedstocks in large central plants through steam methane reforming (SMR) or coal gasification, methods that have been in use since the 1970s. Only a small fraction of the hydrogen produced today can rightly be called “renewable,” being produced from electrolysis with power generated from hydroelectric, wind or solar sources. But that share is beginning to grow at an exponential rate, and with it so are novel ways of producing, delivering, storing, converting and using hydrogen as a raw material.
According to a 2021 estimate by the Energy Transitions Commission, it will require $15 trillion in investment to decarbonise the world’s manufacturing industries using hydrogen-based technologies by 2050.7 If that figure seems arbitrary or prohibitive, the reality is that where there may have been skepticism before, industrial consumers in many sectors are now looking at low-carbon H2 in a new light, especially those with the most GHG emissions to abate like transportation, agriculture, textiles, construction and forestry, and energy-intensive sectors such as ammonia, steel, and in particular cement production, which emits almost as much CO2 as the entire global transportation sector.
ESG initiatives and stronger emissions regulations have pressured the petrochemical industry to make cleaner, higher-grade products. A vehicle can travel twice as far running on a hydrogen fuel cell as it can on a combustion engine using the same amount of gasoline or diesel, a rate of energy efficiency that given recent uncertainty around gas prices is difficult to ignore. It's also one of the reasons why analysts project that demand for low-carbon hydrogen could skyrocket from less than 1 million mt today to 223 million mt by 2050, with renewable power overtaking ammonia production as the biggest consumer of H2 around 15 years from now. And as cost efficiencies rise with demand, an estimated $600 billion in capital expenditure investment opportunities will open up in the US market alone.8
At the same time, government, technological and commercial leaders must overcome significant but solvable challenges to fully realise hydrogen’s benefits and growth potential. Hydrogen-enabling technologies are not one-size-fits all for every application, particularly where it involves transmission from producer to consumer using ammonia, liquid organic hydrogen carriers (LOHC), or metal powders as safer, less volatile H2 storage mediums. Many novel applications for hydrogen are in the research and development stage.
Rising diesel prices due to the 2022 war in Ukraine and the ensuing embargo on Russian crude oil have also put a renewed focus on hydrogen’s market viability as an alternative fuel in the trucking and passenger transportation sectors. The war has put more pressure on the European Union (EU) to become energy independent even faster, ramping up investment in renewable hydrogen and other alternative streams and prompting governments to begin strategically stockpiling H2 as an emergency energy source at major ports such as Antwerp, Belgium.
The H2 Value Chain Explained
The global hydrogen value chain can be broken down into three main stages: production; transmission, storage and distribution; and utilisation and consumption. Hydrogen can be made from a diverse group of production pathways, namely fossil fuels with carbon capture; biomass and human and animal waste streams; and water-splitting technologies, all of which are being actively explored and developed by public and private research. Today the vast majority of low-carbon hydrogen is produced from natural gas, typically methane, using catalytic steam methane reforming to separate the hydrogen molecule from the feedstock, and then applying CCUS to mitigate the amount of carbon released into the environment.
While they are the lowest-cost, highest-capacity option at the moment, fossil streams are being supplemented by fermentation of biomass sources such as switchgrass and poplar trees, and biogas from landfills and agricultural waste, which can also be gasified or reformed and combined with CCUS to provide cleaner water, electricity and raw materials for chemical products.
The most potentially transformative and economically sustainable hydrogen production method is electrolysis, which splits water into H2 and oxygen using electric, thermal, or light energy from solar, wind, nuclear, and other sources. Electrolyzers, including those that use liquid-alkaline and membrane-based technologies, offer near-term commercial viability, with units being constructed today at the multi-megawatt (MW) scale, and a growing list of greenfield projects planned throughout EU and North America in the next decade.
Regardless of how hydrogen is made, it must be safely transported and stored until it’s ready to be used. This is done either as a gas in pipelines and high-pressure tube trailers, as a liquid in specially equipped tanker trucks and ships or using chemical hydrogen carriers such as LOHC or ammonia. H2 in either gaseous or liquid state can be stored in tanks at terminals or in geological formations such as salt domes. The technologies and infrastructure required to support these delivery pathways are at various stages of development, but they must be both cost-effective and meet the level of safety, convenience, reliability, and energy efficiency expected from existing infrastructure for fossil fuels.
Hydrogen is usually consumed through the electric and gas grids in four forms: as an energy storage medium and engine fuel; via commercial and residential heating; in chemical refining, agriculture and food production; and through transportation, using compact H2 fuel cells or traditional combustion engines in shipping, trains, aviation and heavy transport. Low-carbon hydrogen can also be blended with natural gas and injected into existing transmission pipelines and used for heat and power, with lower emissions than natural gas alone.
Prerequisites for H2 Value Chain Success
There are several key factors that must be taken into consideration when it comes to spurring investment and realising the full economic potential of low-carbon hydrogen. Chief among these is the learning rate, which represents the total percentage of cost savings achieved every time the production capacity of a manufactured good is doubled. A high learning rate will enable cost effective H2 production at scale required to meet net zero goals. As has been the case when developing other renewable energy sources, the true learning rate for hydrogen is not yet known, but analytical software tools such as digital twins and artificial intelligence (AI) are making it easier to model how future expansion of the value chain will likely affect cost, which can only be reduced by designing facilities and processes that are testable, reliable, and, most importantly, repeatable.
Getting the price of renewable H2 down to a viable range for industrial and consumer users – the target is $1-2 per kilogram, down from around $6-7 where it is now — will take time, capital, and innovation on the production end, but it also requires a way of balancing the highly complex dynamics that affect the rest of the value chain. Perfecting novel production methods is equally as important as building up a level of reliable storage and distribution infrastructure that is commensurate with the amount of capacity needed to meet global demand.
Advanced automation solutions are needed to manage the trade-off between production costs and the optimal level of output, which not only improves efficiency and ensures that a stable and reliable supply of energy is available. Integrating a wide array of data sources into a single balance-of-plant control system using data management software to gather and contextualise key metrics, such as carbon intensity (CI), is critical to optimising performance, reducing risk, abating emissions and improving efficiencies throughout the many processes involved.
Another essential requirement for growth is a strong culture of collaboration among all stakeholders in the value chain around the world. Business leaders, technology providers, distributors, original equipment manufacturers (OEM), contractors, employees, and government agencies must all work together to scale up and standardise production, transmission, storage, consumption and CCUS techniques. Facility and infrastructure construction projects must be extremely well managed to ensure that they stay on-schedule, on-budget, and meet all regulatory and safety requirements.
The European Clean Hydrogen Alliance, set up in 2020, is a prime example of such a coordinated effort.9 Composed of private companies – including Emerson – public authorities, civil society and other stakeholders, the group meets twice annually with roundtable committees for each stage of the value chain to exchange information and discuss projects and research, all dedicated to the ambitious but increasingly attainable goal of spurring enough investment to establish large-scale, low-carbon hydrogen technology throughout the EU by 2030.
Intensive public-private partnerships like these are the only way to solve the unique technical challenges posed by migrating, integrating and scaling up renewable hydrogen infrastructure. Priorities for ramping up production include maintaining H2 purity from source to tap; increasing the efficiency of water-splitting systems and fuel cells; designing better processes for SMR, gasification, and pyrolysis, which turns biomass into a refinable liquid; and lowering the cost of CCUS technologies.
Transmission, storage and distribution requires that gases and liquids are constantly maintained at very high pressures and low temperatures and that the entire supply stream is free of emissions. Reliable and accurate flow metering, especially during custody transfer from one stakeholder to the next, is crucial for facilitating commercialisation and adapting to price changes, as well as for ensuring safety and gauging CI and other key performance indicators. Hydrogen is also highly corrosive, so measures must be put in place to carefully gauge and protect against metal fatigue in pipelines and any other equipment that comes into contact with the element.
On the utilisation and consumption end of the value chain, engineers are working on ways to mass produce low-cost, lightweight, durable H2 fuel cells for transportation applications. A fuel cell is a compact, suitcase-size or smaller, electrochemical power plant that converts a continuous source of fuel and oxygen into electricity using chemical reactions rather than combustion. Hydrogen fuel cells generate electricity by changing the charge of hydrogen ions moving from the H2 fuel through an electrolyte (usually platinum) along with oxygen, where they react giving off electrons and water vapor. Fuel cells can produce electricity continuously as long as fuel and oxygen are supplied at the proper rate.
For drivers, hydrogen refueling stations look and feel the same as traditional gasoline filling stations, with hand-operated pumps and point-of-sale systems, differing mainly in that they must be equipped to safely and reliably handle the temperatures and pressures required for liquified H2. The liquid must be kept at -40 degrees Celsius (-40 Fahrenheit) after it is compressed so that it does not covert back to gas before it’s dispensed. The number of operating stations, most of which are in Germany, Spain, Japan, China and South Korea, roughly tripled from 215 worldwide in 2012 to 685 in 2021, with 86 stations operating in the US, mostly in California and New England, and hundreds more currently planned in the EU and Asia.10
In addition to building out refueling infrastructure, other consumption-related challenges include integrating hydrogen energy storage and grid services; the development of large-scale hybrid and blended gas systems; new turbines that can generate electricity operating on pure H2; developing new systems integration, testing, and validation techniques; and creating appropriate uniform codes and standards to address all end-use applications.
How Automation Can Help
Automation will play a leading role in bringing the clean-hydrogen economy to fruition by enabling flexibility, stability, availability, and compatibility with fossil fuels and hybrids, while improving quality, safety and repeatability at each step along the way. No area is more important today than in increasing the capacity of electrolyzer plants, which will directly affect the ultimate learning rate and viability of low-carbon H2.
H2 Production
Scaling up electrolysis plants means dramatically increasing the complexity of the process, especially given the previously mentioned balancing act between energy costs, demand and rate of H2 production. Precise calculation and control are essential, since overproduction can drive hydrogen prices down, and the grid can only handle a finite amount of load. Meanwhile continuous optimisation is needed to ensure profitability. Avoiding shutdowns is essential, since restarting an electrolyzer unit is a long, costly and resource-intensive process.
Bigger projects also mean more risk, so OEMs must be able to test iterative designs without disrupting production or increasing safety risk. Highly accurate measurement of all properties of gasses and liquids throughout the process is necessary to ensure sufficiently safe, high-pressure water flow, which prevents temperatures that could ignite hydrogen gas. Monitoring the integrity of electrolyzer membranes is also required to prevent flame, accurately detect the mixture of O2 and H2, and protect against water vapor in the system. Finally, the conductivity of water supplied to electrolysis stack must be tightly controlled and levels in separators gauged to prevent overfills and keep O2 gas from contaminating the water system.
At the heart – or rather brain – of the solution are plant-wide integrated control systems with advanced analytics capabilities. Emerson’s DeltaV™ and Ovation™ distributed control systems (DCS) and the Plantweb™ digital ecosystem make it possible to operate multiple, large, interconnected electrolyzer units by analysing data from necessary process variables and responding to changes in cost and demand in real time. When combined with wireless instrumentation, including guided wave radar level gauges, water conductivity sensors and gas detectors, and final control elements, these software suites can constantly monitor performance and equipment health.
Along with providing greater process visibility, non-intrusive wireless sensors reduce engineering, design and installation time when constructing new electrolyzer plants, while reliably detecting the hydrogen-oxygen mix, identifying leaks, and flagging potential maintenance issues before they lead to shutdowns. Similarly, by providing early indication of problems with water quality prior to it entering the electrolyzer units, wireless sensors can prevent irreversible damage to hardware, while digital twin solutions enable engineers to virtually simulate and test new designs with real-time dashboard process mockups so that flaws and opportunities for efficiency can be better understood without risking any actual impact on production.
Until global electrolysis capacity reaches levels needed to achieve economies of scale, SMR combined with CCUS will continue to be the most used and well-established method for manufacturing decarbonised hydrogen. SMR works by heating methane with steam and a chemical catalyst to produce a mixture of carbon monoxide and hydrogen. Pilot-scale plants have been deployed that integrate systems for
SMR of natural gas with vacuum-swing adsorption (VSA) to manufacture hydrogen for petroleum refining along with concentrated carbon dioxide for use in enhanced oil recovery.
Maintaining the optimal ratio of steam to carbon is critical to ensuring profitability and safety in SMR processes, as is protecting the catalyst from coke buildup, managing general maintenance requirements and minimising energy costs. When paired with gas composition analysers and mass flow sensors, advanced automated process control systems precisely measure and control the rate of natural gas and steam entering the SMR unit to maximise yield, meet H2 purity standards and extend catalyst life, while asset health monitoring software makes it easier to predict faults, automate work orders, and optimise energy consumption and reporting, all of which lead to improved reliability, lower maintenance costs, increased uptime and greater throughput.
CCUS technology also depends on automation to ensure carbon capture rates in SMR and other hydrogen production processes are high enough – usually above 90% — to meet regulatory and commercial CI targets. The three most common CCUS methods in hydrogen production are VSA, pressure swing adsorption (PSA), and post-combustion, amine-based absorption, each of which uses a different chemical reaction to strip and sequester CO2 from the gasses generated by SMR or coal gasification. All three approaches are prone to breakdowns due to high cycle rates, leaks that can affect capture rates, low liquification efficiency and high energy costs.
To mitigate these issues, durable rotary and globe valves specifically rated for high-cycle rates and leak prevention are required throughout the CCUS process, as are special seal requirements for all instrumentation and valves due to the erosion of rubber parts from coming into contact with volatile chemicals. Continuous in-line gas analysers like Emerson’s X-STREAM system ensure that the composition and properties of gasses are within desired ranges. Energy management information systems (EMIS) that monitor trends and efficiencies in power usage is essential to controlling costs, while pervasive sensing networks together with alarm management tools and advanced process control systems minimise safety risks by providing early warning of containment loss and certifying that CO2 capture rates are sufficient to meet CI goals.
H2 Transmission, Distribution and Storage
Moving to the transmission, distribution and storage stage of the value chain, automation can be particularly beneficial in gas blending and pipeline injection systems. The biggest challenges include managing the safety and environmental risk of overpressure, high process noise levels, steel embrittlement and containment loss. All valves and final control elements must be reliable in high-vibration, high-pressure conditions, and be able to operate without leaks. There must also be a way to continuously measure the chemical composition of products in the blending system so that the correct mixture of hydrogen and natural gas is always maintained.
To achieve this, blending system operators can use gas chromatographs that provide full compositional data of the product stream in real time. Application-specific, high-pressure valves that use double-stage actuators and block-and-bleed designs are necessary to adhere to strict shutoff requirements, especially in case of emergencies. Superior valve packing technology with die-formed expanded graphite that meets the highest possible emissions class for their design should be used to meet emissions compliance standards and minimise product losses. Wireless vibration detectors and noise attenuation devices, such as Emerson’s patented WhisperTube system, can help suppress process noise in pipelines and monitor the health of auxiliary equipment.
H2 Consumption and Utilisation
In the third and final stage of the value chain, consumption and utilisation, automation technologies are being applied to improve the performance and reliability of both fuel cells and refueling stations. Like all fuel cell technologies currently being developed, hydrogen fuel cells require precise measurement and control capabilities to ensure that the electrochemical energy conversion process is sustained with the proper flow rates and pressures, which are relatively high. The cost of making platinum electrolytes can also be high, although new methods of reducing the amount required are in development.
Mobile automation solutions, such as logic controllers, solenoid valves and pressure regulators, are available that are reliable and durable enough to ensure that the optimum levels of hydrogen and oxygen under the right pressure are fed to the fuel cell. Because each application is different and the safety concerns given the pressures involved, these technologies are scalable and rated for everything from passenger cars to cargo vessels and everything in between.
In the case of H2 filling stations, advanced automation technologies such as Coriolis mass flow meters with 0.5% accuracy, microprocessor-based controllers that allow precise algorithmic pressure control, long-distance hydrogen flame detectors, non-intrusive temperature sensors rated for extreme cold, and valves able to handle high operating pressures of up to 15,000 pounds per square inch, have all been developed specifically to suit hydrogen fueling applications, helping to make them safer, easier to maintain and more commercially viable as an alternative to gas stations.
Automation Expertise Key to H2 Economy
Renewable hydrogen may well represent the world’s best opportunity to support growing energy demand while reducing its CO2 footprint by decarbonising sectors whose emissions are the most difficult to abate. As efforts to scale up the H2 value chain continue, today’s technology is ready to safely produce, move and use hydrogen, with storage applications that will help stabilize variable output of other renewable sources to improve the dependability of supply and demand.
Low-carbon energy is still costly but is no longer cost prohibitive, although mass production on a global scale is several years away. The interdependence of the value chain requires concurrent development and adoption across many industries, which means widespread adoption will take time, with the scale of production the key factor in driving cost-efficient manufacturing for critical infrastructure like electrolyzers, fuel cells and refueling equipment.
As an automation technology leader, Emerson is dedicated to collaborating with engineers, builders, operators and end users around the world to scale designs and capacity in response to market demand, execute projects on-time and on-budget with low complexity, select scalable, advanced technology platforms, reduce cost and complexity of production and distribution, and above all operate safely, reliably and profitably.
For more information, visit: Emerson.com/hydrogen-value-chain
References
- United States Environmental Protection Agency, Global Greenhouse Gas Emissions Data.
- National Geographic, “Human-made materials now equal weight of all life on Earth,” Dec. 9, 2020.
- United States Environmental Protection Agency, US Inventory of Greenhouse Gas Emissions and Sinks, 1990-2020.
- International Renewable Energy Agency, Renewable Capacity Highlights.
- Bloomberg, “Hydrogen Is a Trillion Dollar Bet on the Future,” Dec. 2, 2020.
- Wood Mackenzie, “The Rise of the Hydrogen Economy.”
- Reuters, “$15 trillion global hydrogen investment needed to 2050-research,” Apr. 26, 2021.
- Wood Mackenzie, “Hydrogen: the US$600 billion investment opportunity,” Apr.6, 2022.
- European Clean Hydrogen Alliance.
- H2Stations.org by LBST.
Emerson Automation Solutions
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