[ production ] green hydrogen could be used to co-fire current coal and natural gas facilities to increase efficiency and reduce pollution .
Something ’ s got to give
While there are some common drawbacks with hydrogen – including storage , transportation , and safety – none are viewed as obstacles large enough to deflate hydrogen ’ s potential as an ideal fuel of the future .
The problem continues to be the limitations of current production techniques . While hydrogen is abundant , it is almost always found within compounds , like water ( H 2
O ) or methane ( CH 4
). Separating hydrogen from methane using steam methane reforming ( SMR ), also referred to as grey hydrogen , is by far the most common commercial option and , up until now , the most cost-effective .
with a recipe that essentially consisted of soda cans , seawater , and caffeine .
Documented in a paper published in the journal Cell Reports Physical Science , researchers dropped aluminum pellets , which had been pretreated with a rare-metal alloy , into filtered seawater . The process released hydrogen , but at a very slow pace . By adding caffeine , the team was able to significantly speed up the process .
“ This is very interesting for maritime applications like boats or underwater vehicles because you wouldn ’ t have to carry around seawater – it ’ s readily available ,” said Aly Kombargi , a PhD student in MIT ’ s Department of Mechanical Engineering and the lead author of the study , in a recent interview .
However , a byproduct of the SMR includes carbon dioxide ( CO 2
), which contributes to climate change and can have negative environmental and health impacts . As a result , SMR increasingly requires carbon capture and storage , which increases both the cost and complexity of the production process , ultimately inflating the final price of the fuel .
Electrolysis – the process of running an electric current through clean , distilled water to separate the hydrogen from oxygen – does not produce any byproducts other than hydrogen and oxygen . However , it currently requires an excessive amount of electricity . In fact , according to some studies the process requires about 54 kWh of electricity ( input ) to produce just one kilogram of hydrogen – which results in 33 kWh hours of electricity ( output ). With almost a 40 % loss in usable energy , transitioning to this form of green hydrogen will require significant improvements in the process .
Kicking the can down the road
In an effort to move hydrogen forward , MIT recently innovated a clever solution to produce hydrogen
Aluminum , an abundant and inexpensive material with high energy density per volume , holds significant potential for hydrogen gas generation through water splitting . In a solution developed by MIT researchers , the aluminum surface is treated with a liquid metal eutectic , allowing its exothermic reaction with water . Seawater , an abundant ionic solution , favors complete recovery of the eutectic post-reaction . Approaches such as reacting at elevated solution temperature and catalyst addition were tested to identify optimal reaction conditions , ensuring high hydrogen production rates , yields , and eutectic recovery . Reprinted from Kombargi , Aly et al ., “ Enhanced recovery of activation metals for accelerated hydrogen generation from aluminum and seawater ,” Cell Reports Physical
Science , Vol 5 , Issue 8 , August 21 , 2024 , under the Creative Commons CC-BY-NC license .
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