Plants use photosynthesis to convert carbon dioxide (CO)2) into molecules that can be metabolized. However, this is not the only process that can produce these molecules. paperpublished on October 23rd. Jouleis considering the possibility of nourishing plants through a process that allows them to grow without photosynthesis at all.
If this could be achieved, plants would be able to grow without sunlight, opening the door to what the paper calls “electric farming.” The paper foresees a utopian future in which crops could be grown in all kinds of places where farming is currently impossible. The paper cites “urban centers, arid deserts, and even space environments” as possibilities, but vast tracts of land are currently used for agriculture. You can also replant trees. They also speculate about the possibility of using this technology in space or on Mars.
The techniques behind these lofty goals are relatively mundane. electrolyticwhich is the use of electrical current to cause a chemical reaction. This process is hundreds of years old and was pioneered in the late 18th century. Famous for its use by British chemist Sir Humphrey Davy to isolate multiple new elements in the early 1800s. Today it is used for all sorts of things. metal refining to hair removal.
Electrolysis of CO2 Create simple molecules related to various basic hydrocarbons. Examples include methanol, ethanol, ethylene, formate, acetate, etc. However, not all of these can be metabolized by plants, and those that can be metabolized, namely ethanol and acetate, are relatively difficult to produce.
Feng Jiao, one of the paper’s co-authors, explains: popular science‘In basic CO2 In electrolysis, acetate is a minor product and the selectivity is less than 10%. ” This number needs to increase significantly for electrolysis to become a viable source of plant nutrition. This paper describes an important advance in this field: the use of a two-step approach that the researchers refer to as a “tandem electrolysis process.” During this process, CO2 It is first reduced to carbon monoxide (CO). The second step converts the CO to acetate.
This avoids problems with direct conversion of CO.2 To acetic acid:CO2 is an acidic gas, but acetic acid, as an anion, is basic. In contrast, CO is not acidic, and as Jiao explains, “The resulting high pH promotes the formation of acetate during the electrocatalytic CO reduction reaction. This is why the tandem process That’s why it shows much higher efficiency in “How high?” “With this process, almost 90% acetate selectivity can be achieved,” Jiao said.
The remaining 10% are by-products, primarily ethylene and hydrogen. As Zhao points out, both can be put to good use.[Ethylene and hydrogen] It is a versatile chemical widely used in industry and can be recycled for other uses, such as converting ethylene into plastics and polymers. ”
Of course, electrolysis, as the name suggests, requires electricity. In this respect, electric farming is fundamentally different from conventional farming. Farms obviously consume electricity, but at the most basic level, photosynthesis does not require electricity.
In an ideal world, power for electric farming would come from renewable sources, Zhao says, but he admits that’s not the case. have “The electricity can be sourced from the existing grid and does not necessarily have to be renewable.” The paper envisions growing plants in tiered structures with rooftop solar panels. (Harnessing solar energy could also be beneficial, Zhao says, because “some plants may grow better under low-light conditions than in complete darkness.”)
However, to introduce electric farming on a large scale, many About solar panels. The paper estimates that electric agriculture would require 19,600 TWh per year to feed the entire United States using tandem processes. That’s almost five times more than in the United States. Overall electricity demand In 2023.
Of course, no one is advocating a large-scale electrolysis-based restructuring of the U.S. food chain, and electric farming could be deployed on a much smaller scale to grow food in urban food deserts, for example. You could also do it like this. But beyond such uses, the obvious question is whether there is any benefit to harnessing solar energy for electrolysis, rather than just allowing plants to utilize it for photosynthesis. That’s it.
The paper states that electrolysis is itself a significantly more efficient process than photosynthesis.2solar, water, etc.), electric farming is at least four times more efficient at converting sunlight to food than traditional farming. ” It may also have other benefits, such as reducing fertilizer runoff. “Growing plants in a controlled environment can greatly improve fertilizer utilization by preventing runoff,” Zhao said. Combined with high conversion efficiency from solar energy to biomass, [electro-agriculture] Fertilizer waste could be reduced by as much as 90%. ”
Beyond the power issue, another pressing question regarding the viability of electric farming is where the CO is generated.2 It will come from Plants grown outdoors photosynthesize carbon dioxide from the atmosphere2However, electric farming requires a dedicated gas source. This paper investigates how much of the U.S. population could be fed by capturing 963 million tons of carbon dioxide.2 Currently, electricity is generated by powering the industrial sector in the United States, which reaches 56% of the population. Applying this to the amount of CO2 The amount needed to feed the entire U.S. population comes out to 1,719 Mt.
Again, this is a lot. For comparison, net emissions across the United States in 2024 were 5,489 tons of CO .2– Equivalent. In theory, this sounds like the perfect use for these emissions, but carbon capture and storage has long been proposed as a silver bullet against climate change, but as of 2024 it remains a hypothetical. It’s just a solution above. Only 50 CCS projects in operation A total of 51 million tons of CO can be captured worldwide2 per year.
Despite the paper’s vision of the future, “half of the [the USA’s] land [could be freed] “For ecosystem restoration and natural carbon sequestration,” the idea of using electrolysis as a large-scale alternative to conventional agriculture seems a long way off, at least on Earth. As the paper points out, Mars’ atmosphere is 95% CO2This may perhaps suggest another reason why “much of the recent research seeks to push electric farming technologies towards commercialization.”
Returning to Earth, it is no exaggeration to say that while the efficiency of acetate production has improved dramatically, carbon dioxide emissions have increased.2 Electrolysis is a promising prospect, but there are significant challenges to its realization. Jiao predicts that this new technology could find niche applications within 10 years, but ultimately, “growing plants without light is still in its infancy. Further research and development is required to fully commercialize and realize its full potential.”
