Have you ever noticed that most portrayals of the distant future in print or film show gleaming clean cities and sparkling blue skies? This is because in these visions, the primary power source is derived by hydrogen rather than fossil fuels.
Hydrogen is the simplest - and most abundant - element in the universe. Atomic hydrogen consists of one proton and one electron. The lightest of all the elements, it has an atomic weight of 1.Molecular hydrogen is a binary molecule composed of two hydrogen atoms.
Hydrogen readily reacts with other elements (a reductive reaction, for you chemistry buffs) such as oxygen or carbon. The reaction products become water or methane, respectively. The reaction is highly exothermic, giving off huge quantities of energy as heat and light. The Hindenberg blimp went up in one of the most famous fireballs in history when the hydrogen gas it used for buoyancy ignited with atmospheric oxygen.
In the presence of a catalyst like platinum hydrogen dissociates into protons and electrons. A second catalyst, often nickel, combines the hydrogen with oxygen, generating an electric current. This is the basis for hydrogen fuel cells, which are an important component of a hydrogen economy.
Scientists view the energy potential of hydrogen, and its clean byproducts, as the logical replacement for today’s carbon economy, based on the combustion of fossil fuels and its emissions of the greenhouse gas carbon dioxide.
How is hydrogen made? Commercial hydrogen is typically produced by a process called steam-methane reforming. Methane is combined with1300o F steam in the presence of a catalyst. The byproducts are hydrogen and carbon dioxide.
The use of fossil fuels to generate the steam for steam-methane reforming adds to the carbon dioxide byproduct from hydrogen manufacture.
Hydrogen can also be split from the oxygen in water molecules by the process of electrolysis using high-power electrodes submerged in water. I recall producing hydrogen and oxygen gas on a small scale in my high school chemistry class using distilled water in two test tubes. Introducing a flame to the generated gas produced a satisfying “pop”, which recombined the hydrogen and oxygen gases back into water.
Gray, Blue or Green Hydrogen? In terms of its carbon footprint, not all hydrogen is equal. Hydrogen can be divided into three categories, depending on its manufacture. The hydrogen produced by steam-methane reforming is classified as “gray” hydrogen, which generates the highest mass of carbon dioxide per unit mass of hydrogen. If the heat source utilizes a renewable energy source, and/or carbon capture technology sequesters the carbon dioxide reaction byproduct, that hydrogen is classified as “blue”. Hydrogen electrolyzed by a fossil fuel power source is also considered “blue”.
Electrolysis from a clean power source (fusion, nuclear, or renewable generation like wind or solar) produces“ green” hydrogen.
How will hydrogen technologies be deployed? The fascinating thing about the hydrolysis of water, is that the process is completely reversible. This lends itself to applications for energy storage, and energy generation.
Most forms of renewable electrical energy production are intermittent, making it difficult and expensive to integrate the power generated into a large energy grid. The wind only blows on windy days, and seldom at night. The sun only shines in the day. That lack of reliability is mitigated by natural gas power generation plants that can nimbly make up the difference in demand verses production.
Electrolytic hydrogen production is an energy storage technology being considered by electric utilities. But it comes with its challenges. First, a ready water source is needed. Once generated, the hydrogen needs to be either stored on site or piped to the urban centers where it is ultimately used.
Fuel cells recombine hydrogen and oxygen in the presence of a catalyst to generate electricity. They are currently deployed for both portable and permanent backup power for homes and businesses, much like a fossil fuel-based generator. They are envisioned as the future power plant for electric vehicles, largely replacing bulky lithium hydride battery systems.
Fuel cells are being deployed or developed for the full range of electrified industrial applications: turboprop aircraft, 300-ton mining dump trucks, cargo ships, port terminal equipment, locomotives, agricultural machinery, long-haul semi tractors, local delivery trucks, and of course passenger vehicles.
Hydrogen fuel cells largely overcome the primary obstacles to electric vehicle adoption by most consumers: range anxiety and lengthy recharge times. According to the US EPA, contemporary fuel cell EV’s have a driving range of between 312 and 380 miles. Refilling is as simple as recharging the tank with compressed hydrogen gas, a process taking mere minutes.
Hydrogen is also replacing natural gas and liquid petroleum distillates for direct combustion applications. Airbus is developing storage technologies for hydrogen powered jet aircraft, the final hurdle to deployment. Their conceptual airframe designs utilize a larger fuselage for hydrogen fuel storage rather than in the wings like in contemporary aircraft.
Liquid hydrogen and oxygen fuel has been a mainstay of rocket propulsion for decades.
Several demonstration projects and feasibility studies are evaluating the repurposing natural gas pipelines and infrastructure to carry hydrogen. Conversion costs to carry pure hydrogen are roughly 15% of a brand-new network. Pipe-delivered hydrogen would serve the same purposes as natural gas – heating homes, commercial buildings and for industrial processes.
How far away is it? Two hurdles must be overcome to transition to a hydrogen economy: cost and scale.
As of 2018, global production of hydrogen was 60 million metric tons. Compare that to last year’s global oil production, 4.2 billion metric tons. Most of the hydrogen currently produced is used in the petrochemical industry. With the exception of its use in fossil fuel production, hydrogen will still be required for production of fertilizers, treating metals and processing foods. Scaling up production of blue and green hydrogen will require billions of dollars of investment to keep up with the demand created by electrification of transportation and replacement of natural gas.
It costs $0.70 to $2.20 per kilogram to produce gray hydrogen. Blue hydrogen costs between $1.30 to $2.90due to the cost of carbon sequestration, making it cost-competitive only when hydrocarbon fuel and feedstock costs are low. Over time, the cost of green hydrogen will fall below the cost of gray hydrogen as renewable and fusion energy dominates the power grid. The cost of renewable power is already cost-competitive with fossil fuel power generation and is expected to decline over time as the technologies mature and scale up.
So how close are we to seeing a hydrogen economy? I expect to purchase a fuel cell power plant within the next five years to run my parked recreational vehicle. My next passenger vehicle will be a battery-powered EV. By 2030, my new vehicles will be powered by fuel cells.
Green hydrogen production will track closely with the electrification of transportation. As I noted in my June2021 newsletter, “Hydrocarbon fuel consumption will peak in the mid-2020s. Neighborhood gas stations as we know them will experience a rise in business failures by the late 2020s. By 2035 gas stations will be sited primarily near freeway interchanges or along busy arterial corridors. Grocery stores or other big-box business locations with large parking lots and long customer visit times will deploy more fast-charging stations (440 volts). By the early 2030’s a significant percentage of EVs will feature hydrogen fuel cells. Hydrogen recharge will be offered at the remaining gas stations and as stand-alone facilities.”
I’ll stand by my prediction for EV adoption. The hydrogen economy will be dominant over the hydrocarbon economy by the early 2030s.
For further readinghttps://www.statista.com/statistics/1121207/global-hydrogen-production/https://www.eia.gov/energyexplained/hydrogen/production-of-hydrogen.phphttps://www.hydrogenfuelnews.com/are-fuel-cell-generators-the-future-for-rvs/8540128/https://www.airbus.com/newsroom/stories/hydrogen-aviation-understanding-challenges-to-widespread-adoption.htmlhttps://www.seattletimes.com/business/seattle-rocket-scientists-turn-attention-to-mining-nearing-completion-of-zero-emissions-engine-for-huge-industrial-dump-truck/https://www.offshore-energy.biz/flagships-set-to-debut-worlds-1st-hydrogen-powered-commercial-cargo-ship/https://www.energy.gov/sites/prod/files/2019/10/f68/fcto-h2-at-ports-workshop-2019-viii3-steele.pdfhttps://www.railwaygazette.com/traction-and-rolling-stock/indian-railways-to-test-fuel-cell-trains/59694.articlehttps://fuelcellsworks.com/news/hydrogen-fuel-is-shaping-the-future-of-agriculture/#:~:text=Hydrogen%20Fuel%20Can%20Help%20Make%20Farming%20Sustainable&text=Hydrogen%20fuel%20cell%20alternatives%20to,agriculture%20away%20from%20fossil%20fuels.
https://techcrunch.com/2021/08/11/hyzon-motors-has-begun-shipping-hydrogen-fuel-cell-trucks-to-customers/https://trucknbus.hyundai.com/global/en/products/truck/xcient-fuel-cellhttps://www.siemens-energy.com/global/en/news/magazine/2020/repurposing-natural-gas-infrastructure-for-hydrogen.htmlhttps://extranet.acer.europa.eu/Official_documents/Acts_of_the_Agency/Publication/Transporting%20Pure%20Hydrogen%20by%20Repurposing%20Existing%20Gas%20Infrastructure_Overview%20of%20studies.pdfhttps://www.velaw.com/insights/hydrogen-production-technology-and-infrastructure-restrictions/https://www.eia.gov/energyexplained/hydrogen/use-of-hydrogen.phphttps://www.rechargenews.com/energy-transition/green-hydrogen-will-be-cost-competitive-with-grey-h2-by-2030-without-a-carbon-price/2-1-1001867
