Tag Archives: ammonia

New ammonia production method could cut 2% of greenhouse gas global output

A farmer sprays liquid urea ammonium nitrate fertilizer to pre-emergent crops. Credit: Flickr.

About 50% of the world’s food production relies on ammonia fertilizer, an important source of nitrogen that is essential for plant growth. In some fields, it is not uncommon to see 90 kg (200 pounds) of ammonia per acre for each growing season. Elsewhere, ammonia is a valuable ingredient used to make pharmaceuticals, plastics, textiles, explosives, and much more. In other words, ammonia provides an essential service to modern society. There’s just one problem: ammonia production is hugely taxing on the environment, being responsible for about 2% of the global CO2 output. Its carbon footprint is equivalent to all the greenhouse gas emissions released by South Africa.

But that may change since scientists at Monash University in Australia have devised a novel ‘green’ production method for ammonia. To make ammonia today, industrial plants employ what’s known as the Haber-Bosch cycle, during which methane gas is refined to produce hydrogen, which reacts with nitrogen from the atmosphere to synthesize ammonia. In the process, about six tons of carbon dioxide is released for every 1.1 tons of hydrogen.

Besides releasing copious amounts of carbon dioxide that warms the atmosphere, industrial-scale ammonia production also causes nitrate pollution as a byproduct, which often ends up in rivers and groundwater.

The alternative ammonia production method developed at Monash came about while the researchers were focused on an entirely different goal. During the grim 2020 COVID lockdown, researchers Alexandr Simonov and Bryan Suryanto working at the lab of Chemistry professor Doug MacFarlane wanted to make bleach from saltwater using electrolysis —  the process of using electricity to split water into hydrogen and oxygen.

This environmentally-friendly bleach could be used to disinfect hospital surfaces while the byproduct alkaline solution is great for handwashing, being kinder to the skin than regular soap. But in the process, the scientists realized that the phosphonium salts they were working with could be precursor chemicals for making ammonia.

Much to their amazement, the researchers were able to  “produce ammonia at room temperature, at high, practical rates and efficiency.” No methane – or any kind of fossil fuel for that matter – was involved in the green ammonia synthesis, which can be powered by electricity from renewable energy sources.

The prototype used in the research to produce ‘green’ ammonia without any methane input. Credit: ACES Electromaterials.

This is not the first time that ammonia has been produced from green sources, but the previous effort only yielded small amounts, not enough to be commercially viable at least. In fact, when Suryanto shared the results of the experiments with his colleagues, everyone was dumbfounded.

When Suryanto shared the results of the experiments with his colleagues, everyone was dumbfounded by the excellent output.

“To be honest, the eureka moment was not really ‘Eureka!’, it was more like, ‘Are you sure? I think you need to do that again,’” Professor MacFarlane said in a statement.

“It takes a long time to really believe it. I don’t know that we’ve yet really had a proper celebration. The launch of our spin-out company will possibly be the time that we genuinely celebrate all of this.”

The Monash researchers are currently working with a local company called Jupiter Ionics to bring their ammonia manufacturing method to market.

“The technology opens a broad range of possibilities for future scale-up to very large production facilities for export, attached to dedicated solar and wind farms,” Professor MacFarlane says.

Unlike the huge behemoth industrial plants required to produce ammonia at scale with the Haber-Bosch technique, the new method can produce green ammonia at much smaller plants.

“You don’t need a huge chemical engineering setup. They can be as small as a thick iPad, and that could make a small amount of ammonia continuously to run a commercial greenhouse or hydroponics setup, for example,” Professor MacFarlane said.

“It means that the distributed production of fertilizers becomes possible because the ammonia manufacturing unit is so small and simply constructed,” he added.

Ammonia is obviously coveted in agriculture, but it can also just well double as fuel in transportation. A lot of attention is given to fuel cells that use hydrogen to power vehicles, but ammonia is safer because it’s less combustible and it’s much easier to store than the lightest molecule in the universe that has a tendency to easily escape from tanks. Ammonia’s biggest downside, though, is that it is an important source of nitrogen oxides that is extremely harmful to our health.

The new findings appeared in the journal Science.

Scientists potty-train cows to tackle climate change

calf in a latrine undergoing MooLoo training. Credit: FBN.

Cow farms produce a lot of waste that harms the environment by producing greenhouse gases and contaminating the local soil and waterways. Researchers in Germany want to minimize these impacts by proposing a seemingly wacky, but effective and novel way to manage cattle urine and feces: just potty-train the cows.

Just crazy enough to work

The beef and dairy industry is among the most environmentally damaging in the world for a myriad of reasons. Intensive livestock breeding requires a lot of feedstock, water, and land, and produces copious amounts of greenhouse gases that heat the planet’s atmosphere.

A report by the UN’s Food and Agriculture Organization estimates that livestock accounts for nearly 15% of man-made greenhouse gas emissions. You may have heard that a lot of methane is produced by cattle burps and farts, but they produce another potent greenhouse gas that is often overlooked.

When a cow’s feces and urine combine, they produce ammonia due to the enzymatic hydrolysis of urea in the urine by urease in the feces. Further down the stream, when ammonia is leached into the soil, microbes eat it up, generating nitrous oxide as a byproduct, the third-most important greenhouse gas after methane and carbon dioxide.

“About 95% of ammonia emissions come from agriculture, and a considerable proportion comes from cattle farming, either directly from barn air or indirectly from slurry. Ammonia is an indirect greenhouse gas. Ammonia is responsible for a large amount of atmospheric N deposition which in turn leads to eutrophication of the soil and water, soil acidification, and direct plant damage. In accordance with the National Emission Reduction Commitment (NERC) from 2016, Germany has committed itself to reduce its emissions of ammonia by 29% compared to 2005. Ammonia is released when urine and feces meet. It is formed by the enzymatic hydrolysis of urea in the urine by urease in the feces,”  Jan Langbein,  an animal psychologist at the Research Institute for Farm Animal Biology (FBN) and co-author of the new study, told ZME Science.

If you thought cows are dumb, I have moos for you. Cows are actually quite intelligent animals that are known to interact in socially complex ways. For instance, they can develop friendships over time and, conversely, will sometimes hold grudges against other cows that treat them badly.

Far from being mere burger and milk machines, cows are sentient and well emotionally developed. Cognitively speaking, they have a level of performance comparable to that of children, with research showing they possess complex spatial memory, can discriminate between individual cows or humans, and display a full range of personality traits, such as shyness, boldness, sociability, and gregariousness.

Bearing all of this in mind, the researchers in Germany believed that cows were clever enough to be potty-trained — and they were right.

Writing in the journal Current Biology, they describe their process, dubbed MooLoo training, by which 16 calves were trained to urinate in latrines fitted inside their barn with a combination of reward and mild punishment.

Researchers carefully watch calves undergoing MooLoo potty training. Credit: FBN.

After they became accustomed to the experimental environment and learned how to enter and exit the gates to the latrine, the cows were taught how to use them. Every time they urinated into the designated area, they received a food reward consisting of a mixture of molasses and glucose or crushed barley. When they urinated outside the toilet, the researchers conditioned them against this behavior by inflicting a mild punishment. Initially, the negative stimulus consisted of playing an annoying sound through headphones placed inside the cow’s ears, however, the animals couldn’t seem to care less. Ultimately, a spray of water worked as a gentle deterrent, and the researchers stuck with that for the rest of the training.

In time, 11 out of the 16 calves learned to enter the latrine only when they needed to urinate and how to use the toilets properly, thereby avoiding ammonia production.

The researchers are confident they can refine their training method to improve their training conversion and scale it even for farms with thousands of individuals.

“We are preparing a follow-up project, in which we want to realize our results, which were worked out under experimental conditions, under practical conditions. For this purpose, the entire training procedure must be automated. Appropriate sensors should detect urination and trigger a reward output in case of urination in the latrine. For now, we are focusing on dairy cows that are kept indoors. In the pasture, the distances for the cow are significantly longer,” Langbein said.

Building designated latrines, fitting them with sensors and automation machines, and training calves sounds prohibitively expensive — and it might very well be. However, seeing how the livestock sector generates copious amounts of emissions, farmers may be incentivized to go down this route through government subsidies. Alternatively, a carbon tax may level the playing field in the market by rewarding farmers who produce less ammonia with carbon credits.

In the not-so-distant future, don’t be surprised to see cows queuing for the toilet like in a busy pub.

US astronauts evacuated as ammonia leak threatened the ISS [UPDATE: no leak, hatch reopened]

The threat of a possible ammonia leak in the US sector of the International Space Station (ISS) forced the American astronauts to abandon their research and relocate to the Russian quarters. The hatch was reopened hours later after no leak was detected, NASA reported.

Mission control, NASA/ESA confirmed there was no ammonia leak, hoping to get astronauts back into USOS as soon as possible. All research was successfully protected, and nothing was lost, though some replanning is required.

“At this time the team does not believe we leaked ammonia,” ISS program manager Mike Suffredini said. “There was never any risk to the crew,” he added.

There alarm was raised when astronauts reported an increase in water pressure in thermal loop B, which is only indicative of an ammonia leak. The crew took refuge in the Russian quarters and planned to stay there for a week in case a leak actually existed, but now, they’re trying to move back to their own area.

NASA says the false alarm may have been caused by a “transient error message in one of the station’s computer relay systems, called a multiplexer-demultiplexer.” So – not so much a leak, and more like a sensor error. NASA continues to analyze the situation to see if there are further issues with the equipment. The response from astronauts was excellent, as expected.

“The safety of the crew has been secured by prompt joint action by the US and Russian crewmembers, as well as by mission control staff in Moscow and Houston,” said the head of the Russian Mission Control Center, Maksim Matyushin. JAXA and ESA also helped on the problem.

 

 

MIT scientists have devised a new technique for carbon nanotube sensors, as simple as etching on a sheet of paper. (c) Jan Schnorr

Carbon nanotubes drawn with a pencil render cheap and reliable sensors

Researchers at MIT have developed a novel technique of creating cheap and reliable sensors for toxic gases by simply etching carbon nanotubes with a mechanical pen on a special paper, fitted with electrodes. The method allows for easy to make, cheap and reliable sensors that detect noxious gases in the environment, without the hassle that usually follows carbon nanotube manufacturing.

MIT scientists have devised a new technique for carbon nanotube sensors, as simple as etching on a sheet of paper. (c) Jan Schnorr

MIT scientists have devised a new technique for carbon nanotube sensors, as simple as etching on a sheet of paper. (c) Jan Schnorr

Instead of graphite, MIT chemists developed a special pencil lead made out of compressed carbon nanotube powder, which can be used with any kind of mechanical pencil. A carbon nanotube is a tube shaped carbon molecule arranged in a hexagon lattice, only one nanometer in diameter or 50,000 times thinner than a human hair. Using the pencil,  Timothy Swager, the lead researcher, and colleagues, inscribed a sheet of paper, fitted with electrodes made out of gold. An electrical current was then applied to the sheet of paper, and measured as it flows through the carbon nanotube strip, now transmuted into a resistor.  Many gases bind to the carbon atoms in the carbon nanotubes, and thus disrupt electrical flow. By detecting this flow disruption, the presence of the gas can be determined.

For their research, the MIT scientists focused on detecting minute quantities of ammonia, a highly dangerous gas, but they claim the system can easily be adapted to a slew of gases. Two major advantages of the technique are that it is inexpensive and the “pencil lead” is extremely stable, says Swager. On top of that, conventional carbon nanotube sensors rely on hazardous manufacturing techniques likedissolving nanotubes in a solvent such as dichlorobenzene  – the present research  uses a solvent-free fabrication method.

“I can already think of many ways this technique can be extended to build carbon nanotube devices,” says Zhenan Bao, an associate professor of chemical engineering at Stanford University, who was not part of the research team. “Compared to other typical techniques, such as spin coating, dip coating or inkjet printing, I am impressed with the good reproducibility of sensing response they were able to get.”

The carbon nanotube sensor was described in the journal Angewandte Chemie

source: MIT