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Tag: green ammonia

Coffee Biochar Concrete Carbon Sequestration

Posted on by dishanth
Coffee Biochar Concrete Carbon Sequestration

Coffee is one of the most popular drinks worldwide; on average, 400 billion cups of coffee are consumed each year. As a result, approximately 18 million tonnes of coffee grounds are produced annually. Coffee grounds can be used for a variety of purposes. It can be used to fertilize your garden or added to compost. Coffee grounds can neutralize odors, can be used to exfoliate your skin, tenderize meats, and many other uses.

Despite all of these amazing uses for coffee grounds, the reality is that most of the coffee grounds produced actually end up in landfills; about 75% in fact. Rotting coffee grounds generate methane, a powerful greenhouse gas contributing to warming. Rotting coffee grounds also emit carbon dioxide, nitrous oxide, and ammonia. While there have been programs from coffee shops that will donate their coffee grounds to customers to use in their gardens (Starbucks has been part of the Grounds for Your Garden program since 1995), but most coffee shops are not implementing these initiatives.

Researchers from the Royal Melbourne Institute of Technology University in Australia have found a way to use coffee grounds on a larger scale and to eliminate the risk of them ending up in landfills. And that is to use coffee biochar concrete in the construction industry.

The researchers have developed concrete that is almost 30 percent stronger than traditional concrete by mixing in coffee-derived biochar. The coffee biochar was created using a low-energy process called pyrolysis. The organic waste is heated to 350 degrees Celsius without oxygen to avoid the risk of generating carbon dioxide. Under pyrolysis, organic molecules vibrate and break down into smaller components, creating biochar. This is a similar process that is used to roast unused beans to enhance their taste, except without the use of oxygen.

In coffee biochar concrete, about 15 percent of the sand they would use to make concrete is replaced with the coffee biochar, thus creating new concrete. The coffee biochar is finer than sand, and its porous qualities help to bind to organic material. Reducing the total use of sand in concrete will minimize the construction industry’s environmental footprint. It is said that over 50 billion metric tons of natural sand are used annually in construction. Sand mining significantly stresses ecosystems, including riverbeds and riverbanks, coffee biochar concrete can relieve some of that pressure on the environment.

The cement industry is the third largest source of industrial air pollution, including sulfur dioxide, nitrogen oxides, and carbon monoxide. Moreover, cement currently accounts for around 8% of global carbon dioxide emissions. Turning coffee- biochar into concrete will reduce the construction industry’s reliance on continuous mining of natural resources, making the industry more sustainable.

When introduced into concrete mixtures, the coffee biochar concrete was found to act as a microscopic carbon repository within the concrete matrix. The alkaline conditions within hardened concrete enable biochar to mineralize and firmly bind carbon dioxide into its structure over time. Concrete containing even a small percentage of spent coffee biochar was shown to sequester meaningful quantities of CO2 from the curing process and surrounding environment.

Utilizing waste coffee grounds to synthesize biochar for carbon sequestration could offer a sustainable way to offset concrete’s sizable carbon footprint while giving new purpose to spent grounds. With further research, coffee biochar concrete could provide a feasible carbon capture pathway for the construction industry.

The researchers estimate that if all the waste grounds produced in Australia annually could be converted into coffee biochar, it would amount to roughly 22,500 tonnes. Compare that to the 28 million tonnes of sand that are required to produce over 72 million tonnes of cement concrete in Australia. Just think: Australia has over 13 thousand coffee shops, whereas the United States has over 38 thousand coffee shops. If this project expands outside of Australia, coffee biochar concrete could significantly impact the environment and waste.

The research on coffee biochar concrete is still in the early stages; there is still a lot of testing to be done, but it shows that there are innovative and unique ways to reduce and repurpose organic landfill waste. Once the researchers can account for things like durability, the researchers will collaborate with local councils on future infrastructure projects, including the construction of walkways and pavements. Just think, we are one step closer to adding sustainability into the construction industry and one step closer to walking on coffee biochar concrete!

 

 

 

 

Source   Happy Eco News

New eco-friendly way to make ammonia could be boon for agriculture, hydrogen economy

Posted on by dishanth
New eco-friendly way to make ammonia could be boon for agriculture, hydrogen economy

Chemical engineers at UNSW Sydney have found a way to make ‘green’ ammonia from air, water and renewable electricity that does not require the high temperatures, high pressure and huge infrastructure currently needed to produce this essential compound.

And the new production method — demonstrated in a laboratory-based proof of concept — also has the potential to play a role in the global transition towards a hydrogen economy, where ammonia is increasingly seen as a solution to the problem of storing and transporting hydrogen energy.

In a paper published today in Energy and Environmental Science, the authors from UNSW and University of Sydney say that ammonia synthesis was one of the critical achievements of the 20th century. When used in fertilisers that quadrupled the output of food crops, it enabled agriculture to sustain an ever-expanding global population.

But since the beginning of the 1900s when it was first manufactured on a large scale, production of ammonia has been energy intensive — requiring temperatures higher than 400oC and pressures greater than 200atm — and all powered by fossil fuels.

 

Source: https://www.greencarcongress.com/

 

Dr Emma Lovell, a co-author on the paper from UNSW’s School of Chemical Engineering, says the traditional way to make ammonia — known as the Haber-Bosch process — is only cost-effective when produced on a massive scale due to the huge amounts of energy and expensive materials required.

“The current way we make ammonia via the Haber-Bosch method produces more CO2 than any other chemical-making reaction,” she says.

“In fact, making ammonia consumes about 2 per cent of the world’s energy and makes 1 per cent of its CO2 — which is a huge amount if you think of all the industrial processes that occur around the globe.”

Dr Lovell says in addition to the big carbon footprint left by the Haber-Bosch process, having to produce millions of tonnes of ammonia in centralised locations means even more energy is required to transport it around the world, not to mention the hazards that go with storing large amounts in the one place.

She and her colleagues therefore looked at how to produce it cheaply, on a smaller scale and using renewable energy.

“The way that we did it does not rely on fossil fuel resources, nor emit CO2,” Dr Lovell says.

“And once it becomes available commercially, the technology could be used to produce ammonia directly on site and on demand — farmers could even do this on location using our technology to make fertiliser — which means we negate the need for storage and transport. And we saw tragically in Beirut recently how potentially dangerous storing ammonium nitrate can be.

“So if we can make it locally to use locally, and make it as we need it, then there’s a huge benefit to society as well as the health of the planet.”

 

OUT OF THIN AIR

ARC DECRA Fellow and co-author Dr Ali (Rouhollah) Jalili says trying to convert atmospheric nitrogen (N2) directly to ammonia using electricity “has posed a significant challenge to researchers for the last decade, due to the inherent stability of N2 that makes it difficult to dissolve and dissociate.”

Dr Jalili and his colleagues devised proof-of-concept lab experiments that used plasma (a form of lightning made in a tube) to convert air into an intermediary known among chemists as NOx — either NO2- (nitrite) or NO3- (nitrate). The nitrogen in these compounds is much more reactive than N2 in the air.

“Working with our University of Sydney colleagues, we designed a range of scalable plasma reactors that could generate the NOx intermediary at a significant rate and high energy efficiency,” he says.

“Once we generated that intermediary in water, designing a selective catalyst and scaling the system became significantly easier. The breakthrough of our technology was in the design of the high-performance plasma reactors coupled with electrochemistry.”

Professor Patrick Cullen, who led the University of Sydney team, adds: “Atmospheric plasma is increasingly finding application in green chemistry. By inducing the plasma discharges inside water bubbles, we have developed a means of overcoming the challenges of energy efficiency and process scaling, moving the technology closer to industrial adoption.”

 

STORAGE SOLUTION

Scientia Professor Rose Amal, who is co-director of ARC Training Centre for Global Hydrogen Economy, says in addition to the advantages of being able to scale down the technology, the team’s ‘green’ method of ammonia production could solve the problem of storage and transport of hydrogen energy.

“Hydrogen is very light, so you need a lot of space to store it, otherwise you have to compress or liquify it,” says Professor Amal.

“But liquid ammonia actually stores more hydrogen than liquid hydrogen itself. And so there has been increasing interest in the use of ammonia as a potential energy vector for a carbon-free economy.”

Professor Amal says ammonia could potentially be made in large quantities using the new green method ready for export.

“We can use electrons from solar farms to make ammonia and then export our sunshine as ammonia rather than hydrogen.

“And when it gets to countries like Japan and Germany, they can either split the ammonia and convert it back into hydrogen and nitrogen, or they can use it as a fuel.”

The team will next turn its attention to commercialising this breakthrough, and is seeking to form a spin-out company to take its technology from laboratory-scale into the field.

 

 

Story Source:

Materials provided by University of New South Wales. Original written by Lachlan Gilbert. Note: Content may be edited for style and length.

Journal Reference:

  1. Jing Sun, David Alam, Rahman Daiyan, Hassan Masood, Tianqi Zhang, Renwu Zhou, Patrick Cullen, Emma Catherine Lovell, Ali Rouhollah Jalili, Rose Amal. A hybrid plasma electrocatalytic process for sustainable ammonia production. Energy & Environmental Science, 2021; DOI: 10.1039/D0EE03769A