This MIT system can harness solar energy to produce green hydrogen - Interesting Engineering

This MIT system can harness solar energy to produce green hydrogen
This MIT system can harness solar energy to produce green hydrogenThe new design boosts the efficiency of solar thermochemical hydrogen production from 7 to 40 percent.Jijo MalayilPublished: Oct 17, 2023 10:30 AM ESTinnovationGreen Hydrogen factory conceptScharfsinn86/iStock Get a daily digest of the latest news in tech, science, and technology, delivered right to your mailbox. Subscribe now.By subscribing, you agree to our Terms of Use and Policies You may unsubscribe at any time.In an age where "green" energy sources are given prominence to meet net zero emissions targets, a team of MIT researchers has proposed to create completely green, carbon-free hydrogen fuel using a novel, train-like system of reactors powered entirely by the Sun.The technology uses the Sun's heat to split water and produce hydrogen directly. The engineers outline the conceptual architecture for a system that may efficiently manufacture "solar thermochemical hydrogen" in a report published in the Technology Solar Energy Journal. Today, hydrogen is mainly manufactured using natural gas and other fossil fuels, making the otherwise green power more of a "grey" energy source from its inception to its final usage. See Also Related World first 100% hydrogen gas turbine tested in France 25% of global clean electricity now from nuclear thanks to new UAE reactor Green hydrogen successfully produced from plastic waste According to the team, solar thermochemical hydrogen, or STCH, on the other hand, provides an utterly emission-free alternative since it is powered entirely by renewable solar energy. However, contemporary STCH designs are inefficient: only around 7 percent of incoming sunlight is utilized to produce hydrogen. So far, the outcomes have been low yield and high expense.The design proposed by MIT reseachersMIT Complements current systemsThe MIT system would be coupled with an existing solar heat source, such as a concentrated solar plant (CSP), a circular array of hundreds of mirrors that gather and reflect sunlight to a central receiving tower. The heat from the receiver is then absorbed by an STCH system, which directs it to split water and generate hydrogen. This method differs significantly from electrolysis, which splits water using electricity rather than heat.A two-step thermochemical reaction lies at the heart of a proposed STCH system. The first stage involves exposing water as steam to a metal. As a result, the metal absorbs oxygen from the steam, leaving hydrogen behind. This metal "oxidation" is comparable to iron rusting in the presence of water, but it occurs considerably more quickly. "Once hydrogen is separated, the oxidized (or rusted) metal is reheated in a vacuum, which acts to reverse the rusting process and regenerate the metal. With the oxygen removed, the metal can be cooled and exposed to steam again to produce more hydrogen. This process can be repeated hundreds of times," said a statement from MIT. In this system, each reactor would initially be subjected to the Sun's heat at temperatures of up to 1,500 degrees Celsius in a hot station. This tremendous heat would effectively extract oxygen from the metal of a reactor. That metal would be in a "reduced" condition, ready to absorb oxygen from steam. To do this, the reactor would be moved to a colder station at temperatures of 1,000 degrees Celsius, exposing it to steam to make hydrogen. Efficient systemThe MIT design also includes several energy-saving to counter the typical losses seen in other STCH concepts. Reactors on opposing sides of the circular track are permitted to exchange heat via thermal radiation; hot reactors are cooled, while cool reactors are heated. This keeps the heat contained within the system. The researchers also constructed a second set of reactors that would move in the opposite direction as the first train. This outer train of reactors would run at lower temperatures and would be utilized to expel oxygen from the hotter inner train without the use of energy-intensive mechanical pumps.These outer reactors would also include a second sort of metal that oxidizes readily. The outside reactors would take oxygen from the inner reactors as they circled, thereby de-rusting the original metal without needing energy-intensive vacuum pumps. Both reactor trains would operate constantly, producing independent pure hydrogen and oxygen streams.The team ran comprehensive simulations of the proposed design and discovered that the system would significantly increase the efficiency of solar thermochemical hydrogen generation from 7 percent to 40 percent, as earlier designs had indicated.Researchers say if the system can be put to use efficiently, "it could drastically change our energy future — namely, enabling hydrogen production, 24/7. The ability to make hydrogen is the linchpin to producing liquid fuels from sunlight," said Christopher Muhich, an assistant professor of chemical engineering at Arizona State University, in a statement. Over the next year, the team will construct a prototype of the system, which will be tested in concentrated solar power facilities at the Department of Energy's laboratories, which is sponsoring the study. HomeInnovationAdd Interesting Engineering to your Google News feed.Add Interesting Engineering to your Google News feed.SHOW COMMENT (1) For You How air quality systems could solve the biodiversity crisisMassive volcanic blast on comet unleashes spectacular 'horns'Study finds metal traces in Earth’s stratosphere post rocket launchesHow much matter exists in the universe? Scientists find new resultsWhat's all the fuss about 15-minute cities?Human interbreeding contributed 6% to Neanderthal genome, finds studyStudy reveals Mesolithic Europeans ate seaweed and freshwater plantsAfghanistan’s supercar Simurgh shocks the automotive IndustryCan AI accurately identify patients with respiratory symptoms?10 ancient civil engineering projects still in use Job Board