How to Suck up Carbon Pollution

Scientists have set out a way to suck planet-heating carbon pollution from the air, turn it into sodium bicarbonate and store it in oceans, according to a new paper. The technique could be up to three times more efficient than current carbon capture technology, say the authors of the study, published Wednesday in the journal Science Advances.

Tackling the climate crisis means drastically reducing the burning of fossil fuels, which releases planet-heating pollution. But because humans have already pumped so much of this pollution into the atmosphere and are unlikely to sufficiently reduce emissions in the near term, scientists say we also need to remove it from the airNature does this – forests and oceans, for example, are valuable carbon sinks – but not quickly enough to keep pace with the amounts humans are producing. So we have turned to technology.

One method is to capture carbon pollution directly at the source, for example from steel or cement plants. But another way, which this study focuses on, is “direct air capture.” This involves sucking carbon pollution directly out of the atmosphere and then storing it, often by injecting it into the ground. The problem with direct air capture is that while carbon dioxide may be a very potent planet-heating gas, its concentrations are very small – it makes up about 0.04% of air. This means removing it directly from the air is challenging and expensive.

“It’s a “significant hurdle,” Arup SenGupta, a professor at Lehigh University and a study author. Even the biggest facilities can only remove relatively small amounts and it costs several hundred dollars to remove each ton of carbonClimeworks’ direct air removal project in Iceland is the largest facility, according to the company, and can capture up to 4,000 tons of carbon dioxide a year. That’s equivalent to the carbon pollution produced by fewer than 800 cars over a year. The new technique laid out in the study can help tackle those problems, said SenGupta. The team have used copper to modify the absorbent material used in direct air capture. The result is an absorbent “which can remove CO2 from the atmosphere at ultra-dilute concentration at a capacity which is two to three times greater than existing absorbents,” SenGupta said. This material can be produced easily and cheaply and would help drive down the costs of direct air capture, he added. Once the carbon dioxide is captured, it can then be turned into sodium bicarbonatebaking soda – using seawater and released into the ocean at a small concentration.

The oceansare infinite sinks,” SenGupta explained. “If you put all the CO2 from the atmosphere, emitted every day – or every year – into the ocean, the increase in concentration would be very, very minor.” Gupta’s idea is that direct air capture plants can be located offshore, giving them access to abundant amounts of seawater for the process.


Microwave Air Plasmas Could Replace Fuel For Jet Propulsion

Humans depend on fossil fuels as their primary energy source, especially in transportation. However, fossil fuels are both unsustainable and unsafe, serving as the largest source of greenhouse gas emissions and leading to adverse respiratory effects and devastation due to global warming.

A team of researchers at the Institute of Technological Sciences at Wuhan University has demonstrated a  that uses microwave air plasmas for . They describe the engine in the journal AIP Advances.

The motivation of our work is to help solve the problems owing to humans’ use of fossil fuel combustion engines to power machinery, such as cars and airplanes,” said author Jau Tang, a professor at Wuhan University. “There is no need for fossil fuel with our design, and therefore, there is no carbon emission to cause greenhouse effects and global warming.

Beyond solid, liquid and gas, is the fourth state of matter, consisting of an aggregate of charged ions. It exists naturally in places like the sun’s surface and Earth’s lightning, but it can also be generated. The researchers created a plasma jet by compressing air into high pressures and using a microwave to ionize the pressurized air stream.

This method differs from previous attempts to create plasma jet thrusters in one key way. Other plasma jet thrusters, like NASA‘s Dawn space probe, use xenon plasma, which cannot overcome the friction in Earth’s atmosphere, and are therefore not powerful enough for use in air transportation. Instead, the authors’ plasma jet thruster generates the high-temperature, plasma in situ using only injected air and electricity.

The prototype plasma jet device can lift a 1-kilogram steel ball over a 24-millimeter diameter quartz tube, where the high-pressure air is converted into a by passing through a microwave ionization chamber. To scale, the corresponding thrusting pressure is comparable to a commercial airplane jet engine. By building a large array of these thrusters with high-power microwave sources, the prototype design can be scaled up to a full-sized jet. The authors are working on improving the efficiency of the device toward this goal. “Our results demonstrated that such a jet engine based on microwave air plasma can be a potentially viable alternative to the conventional fossil fuel jet engine,” Tang said.


The Rise Of The Hydrogen Electric Car

China‘s State Council has announced last month a proposal to promote the development and construction of fueling stations for hydrogen fuel-cell cars. It was a Friday, and too late to trade on the news. On Monday, Chinese punters were ready: In the first few minutes of trading, fuel cell-related stocks gained more than $4 billion in market value, with several hitting their daily limits. The bullishness lasted all week. It’s likely to run for much longer. In less than a decade, the Chinese government has used subsidies and other policies to create the world’s largest market for battery-powered electric vehicles. That market isn’t without problems and limits, so the government is looking to diversify its bets on carbon-free transportation. Fuel cells, a technology that’s being hotly pursued in other East Asian countries (as well as the  U.S.), is their favored means of doing it. Chinese investors, having seen the opportunities created by the support for battery-electric vehicles, are right to get in early.

Fuel cells, like batteries, generate electricity that can drive a motor and vehicle. The similarities mostly stop there. Batteries are large, heavy and require charging by electricity that may or may not be generated from renewable resources. By contrast, fuel cells generate electricity (and, as a byproduct, heat and water) when hydrogen interacts with oxygen. They don’t need charging; instead, they require onboard hydrogen tanks, which are both lighter and capable of holding far more energy than a battery (allowing them to travel further). And unlike batteries, which can require hours to charge, vehicles powered in this way can be refueled in minutes, similar to traditional internal combustion engines.

Of course, if it were so easy, hydrogen vehicles would already dominate battery-powered cars (and internal combustion engines, too). Several crucial bottlenecks have inhibited their growth. First, fuel cells are the most expensive components in the car, and for years they’ve made the technology uncompetitive with battery electrics. For example, the Toyota Mirai – the Japanese company’s signature fuel-cell vehicle – sells for around $70,000 (unsubsidized). Meanwhile, Chinese battery-electric vehicles can sell for less than $10,000. Second, fuel cells might be clean-burning but hydrogen is often generated from fossil fuels, including coal. That’s problematic if the goal is carbon reduction. And third, hydrogen infrastructure – everything from pipelines to fueling stations – is both expensive and rare. In China, the cost of a hydrogen station is around $1.5 million. That’s a tough investment to make, especially when there are fewer than 5,000 fuel-cell vehicles operating in the country.

Ultimately, success will require overcoming significant technical and market hurdles. China‘s success in building a battery-electric industry guarantees that it’ll be in the race, if not the eventual leader, in this next stage in decarbonizing transport. For Chinese investors, that’s a bet worth making.


How To Offer Commercially Attractive Carbon-Capturing

Chemical engineers from the Ecole Polytechnique Fédérale de Lausanne  (EPFL ) in Switzerland have designed an easy method to achieve commercially attractive carbon-capturing with metal-organic frameworksMetal-organic frameworks (MOFs) are versatile compounds hosting nano-sized pores in their crystal structure. Because of their nanopores, MOFs are now used in a wide range of applications, including separating petrochemicalsmimicking DNA, and removing heavy metals, fluoride anions, hydrogen, and even gold from waterGas separation in particular is of great interest to a number of industries, such as biogas production, enriching air in metal working, purifying natural gas, and recovering hydrogen from ammonia plants and oil refineries.

The flexible ‘lattice’ structure of metal-organic frameworks soaks up gas molecules that are even larger than its pore window making it difficult to carry out efficient membrane-based separation,” says Kumar Varoon Agrawal, who holds the GAZNAT Chair for Advanced Separations at EPFL Valais Wallis.

Now, scientists from Agrawal’s lab have greatly improved the gas separation by making the MOF lattice structure rigid. They did this by using a novel “post-synthetic rapid heat treatment” method, which basically involved baking a popular MOF called ZIF-8 (zeolitic imidazolate framework 8) at 360°C for a few seconds. The method drastically improved ZIF-8’s gas-separation performance – specifically in ‘carbon capture’, a process that captures carbon dioxide emissions produced from the use of fossil fuels, preventing it from entering the atmosphere. “For the first time, we have achieved commercially attractive dioxide sieving performance a MOF membrane,” says Agrawal.