Will Forests Drive the Hydrogen Economy?

In The Hydrogen Economy (Wiley, 2002), author Jeremy Rifkin advocated shifting to a renewable energy infrastructure based on harnessing hydrogen, the so-called “forever fuel.” Hydrogen’s allure stems from its ubiquity, capacity, and clean emissions. The element can be found nearly everywhere on the planet—including water, fossils, and living organisms—and is a potent energy source for applications like rocket fuel. And when the element is combusted for power, the byproduct it emits is harmless water vapor. “Since hydrogen is found everywhere and is inexhaustible if properly harnessed, every human being on Earth could be ‘empowered,’ making hydrogen energy the first truly democratic energy regime in history,” Rifkin proclaimed in his book.

There have been many challenges, however. Although hydrogen does occur naturally in isolation in some reservoirs, it is primarily found as part of compounds—like H₂O—that require significant energy to separate. Safety concerns (remember the Hindenburg?) have limited the development of hydrogen engine technology. Furthermore, conventional production methods of hydrogen gas (H2), such as steam reforming with natural gas, produce CO₂—thus negating the “clean” promise of this energy source.

Despite these hurdles, the past year has shown a measurable uptick in hydrogen energy production. Two primary drivers have been the war in Ukraine, which has motivated the expansion of renewable energy sources as alternatives to Russian oil, and the U.S. Inflation Reduction Act, which includes support for hydrogen production. Significantly, the new legislation offers credits that make low-carbon hydrogen production cost-competitive with so-called “gray” hydrogen produced via steam reforming, which generates eight to 12 kilograms of CO₂ per kilogram of hydrogen. One emerging industry aims to take advantage of the low-carbon hydrogen trend by producing H2 from an unexpected source: wood waste.

Canada-based Hydrogen Naturally has developed technology to convert residual fiber and waste-wood biomass to what it calls “bright green” hydrogen fuel via gasification. The company aspires to play a pivotal role in the utilization and management of carbon in forests by altering the fate of the material left after timber harvesting. In common practice, this waste-wood fiber is either burned in slash piles or left to rot, releasing stored carbon back into the atmosphere. “It is our conviction that this squanders the work of the tree in extracting the carbon from the air,” argues Ian MacGregor, Hydrogen Naturally’s executive chairman. Instead, by converting this material to clean hydrogen fuel and sequestering the resulting CO₂, the company can take advantage of the stored energy with significantly better carbon performance. In this way, Hydrogen Naturally claims it can produce carbon-negative hydrogen because it sequesters the carbon that would otherwise have been returned to atmosphere. “We think by taking advantage of the carbon concentration of the tree, we have developed a more economical method of extracting carbon from the air,” MacGregor says.

To drive the conversion process, Hydrogen Naturally has conceived and will build the first carbon-capturing hub of its kind, which will cost more than $5 billion. In addition, the company will utilize “the world’s largest system for transporting and sequestering man-made CO₂ at a cost of more than $1 billion,” MacGregor explains. Through past projects, the company has already stored approximately three million metric tons of CO₂ in its Enhanced Oil Recovery (EOR) reservoir in Clive, Alberta, which is operated by Canadian spin-off company Enhance Energy. Hydrogen Naturally plans to build four facilities in North America, each of which will sequester four million metric tons of carbon and produce 160,000 metric tons of hydrogen. (The sequestered CO₂ from these hubs will not be used for EOR.) The first of these hubs will be located near Edmonton, Alberta.

Economics is a driving factor in addition to environmental aims. The Canadian wood pulp industry has faced financial challenges due in part to the narrow profit margins of its products. Hydrogen Naturally has positioned itself as a beneficial partner to the timber industry, offering to make productive use of the leftover fiber from harvested trees and the residual pulp from lumber milling. The company is also collaborating with Fort Nelson First Nations in British Columbia to provide desirable jobs for the Indigenous community.

MacGregor says that the feedstock material is derived from managed forests that are primarily cut for timber (no old-growth forests). A portion of the wood fiber is used for energy in the conversion process: Wood-fired boilers dry the feedstock before the gasification process. A small quantity of ash remains after the production of hydrogen and CO₂, and the company plans to utilize this material as fertilizer in the forests where it harvests its material.

Now that wood is a preferred material for building construction based on its lower carbon emissions than steel and concrete, timber operations will continue to expand. According to a recent United Nations report, the use of primary processed wood products is anticipated to grow nearly 40 percent by 2050. Given forests’ fundamental role in sequestering carbon (among many other ecosystem services), it is therefore crucial to consider the entire carbon life cycle of forest resources.

The intriguing idea of converting residual fiber to hydrogen does raise some questions. For example, dead wood does play a role in forest health, furnishing nutrients for new growth and habitats for various species. Although decaying biomass can make forests more susceptible to fires, the view that such material is waste requiring removal is part of an outdated paradigm. Future efforts to cull post-harvest residue should therefore seek an appropriate balance—removing excess biomass while leaving more nutrient-rich, habitat-conducive materials behind. Another question pertains to using Carbon Capture and Storage as a carbon drawdown strategy. Although sequestering CO₂ deep underground seems sensible, critics point out that it is unproven at scale and maintains reliance on fossil fuels.

Nonetheless, Hydrogen Naturally points to a fascinating future for the energy and forest products industries. With increased chain-of-custody and energy accounting capabilities, one might eventually imagine the ability to purchase construction materials with a carbon-negative designation—made possible by the hydrogen derived as part of their harvesting. Such an achievement would represent a significant step toward the bright green future Rifkin imagined.

The views and conclusions from this author are not necessarily those of ARCHITECT magazine or of The American Institute of Architects.

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