Common kitchen ingredient may be key to world’s green energy transition, scientists say

‘What’s exciting are the possibilities’

Some special chemical properties of baking soda may help develop safe and long-term storage of hydrogen, a fuel seen as essential to achieve “net zero” emissions in the future, according to a new study.

As the world continues to warm at alarming rates due to continued global greenhouse gas emissions, scientists have looked beyond coal, oil, and natural gas towards getting more energy from renewable sources.

Over the recent years, clean hydrogen, produced without fossil fuels, has emerged as a key contendor among renewable energy sources.

Hydrogen being an ubiquitous element, is found in nearly three-fourths of all matter in the known Universe, and is also non-toxic and highly combustible.

However, one major hurdle in utilising the full potential of this clean fuel is that until now there is no safe, cost-effective, and energy-efficient way to store it at large scales.

But a new study, published recently in the journal Green Chemistry, finds baking soda as a potential solution to the big problem.

“You have to be a little creative... Not every chemical is going to be efficient at storing hydrogen. You have to work with what Mother Nature gives you,” said Thomas Autrey from the Pacific Northwest National Laboratory (PNNL) in the US, one of the co-authors of the study.

Scientists agree that achieving safe, long-duration storage is key to hydrogen’s future as a carrier of renewable energy.

There are also attempts across the world to reduce the cost of producing the fuel itself from $5 to $1 per kg of hydrogen in a decade – an 80 per cent reduction.

But without figuring out how to move and store hydrogen, the fuel’s prices may remain high, researchers say.

While it can be compressed into a gas, this requires very high pressures of up to 10,000 pounds per square inch.

Experts say achieving this pressure would need walls of very thick steel or expensive space-grade carbon fiber.

The new study points to the non-toxic and abundant sodium salt of bicarbonate as a potential solution.

Scientists are now studying the hydrogen energy storage properties of the long-known bicarbonate-formate chemical cycle.

Solutions of formate ions – hydrogen and carbon dioxide – in water carry hydrogen based on non-corrosive alkali metal formate.

These ions undergo a reaction with water in the presence of a catalyst, researchers say, leading to hydrogen and bicarbonates – the “baking soda” that scientists like Dr Autrey admire for its properties.

With some tweaks to this process, researchers say an “on-off switch” can be introduced into the bicarbonate-formate cycle, leading to an aqueous solution that can alternately store or release hydrogen.

Scientists say the idea of using formate-bicarbonate salts still needs to be developed into economically feasible scenarios to store greater quantities of hydrogen that meets the industry standards.

But in theory, they say the bicarbonate-formate cycle represents “a feasible green alternative for storing and transporting energy” from hydrogen.

“At present, more information on both the fundamental and systems level is needed to identify the feasible scenarios for using formate/bicarbonate salts for hydrogen/energy storage,” researchers wrote in the study.

Dr Autrey calls the current status of the baking soda idea an “amazing shiny thing,” adding that “what’s exciting are the possibilities”.