March 17, 2023
Carbon capture or bust
Experts say California needs to immediately do more on the state level to incentivize polluters to adopt carbon capture and sequestration if it wants the technology to play a part in helping the state reach carbon neutrality by 2045.
George Peridas, the director of carbon management partnerships at Lawrence Livermore National Laboratory said that he doesn't think polluters will be quick to jump on board with California’s current plan, even with the incentives that exist right now.
“These projects aren’t profitable and are quite an undertaking, so I just can’t see anybody suddenly becoming rich from doing it,” he said.
In fact, tax credits for installing carbon capture technologies have been available to refineries and gas power plants in California since 2018; as of December, last year, when the carbon plan was finalized, not one facility has taken the state up on the offer.
Peridas believes the best path forward is for the state to do as much as it can to pay for the first wave of projects, which will offer valuable lessons about making the projects both cost-effective and efficient.
“The state can say, ‘OK, we’re going to incentivize a first wave of projects, or demonstrations, and we’re going to use those opportunities to bring down costs and to figure out exactly how these plans need to be designed and operated. And then from the learnings, we’re going to have a much smoother path to scale-up,’” Peridas said.
Break it on down
When it comes to studying particles in motion, experimentalists have followed a 100-year-old theory that claims the microscopic motion of a particle is determined by random collisions with molecules of the surrounding medium, regardless of the macroscopic forces that drive that motion.
Scientists at Lawrence Livermore and the Massachusetts Institute of Technology have found that this famous fluid dynamics relation, discovered by Walter Nernst and Albert Einstein in the beginning of the 20th century, breaks down completely under strong spatial confinement inside carbon nanotube pores.
In 1888, Nernst proposed a universal relation between the mobility of a charged particle and its diffusion coefficient. The microscopic origins of this relation were revealed in 1905 by Einstein, during his annus mirabilis period, culminating with his work on Brownian motion. The NE relation, as it is known, is an essential building block of several important theories of ion transport.
Confined micro- and nano-environments, such as carbon nanotube porins, can test the NE relation, because confinement can restrict ion mobility, amplify proximity effects, enhance particle–surface interactions and force unusual long-range structuring of liquids, all of which affect the particle motion.
LLNL engineers and scientists have developed a method for detecting and predicting strut defects in 3D-printed metal lattice structures during a print through a combination of monitoring, imaging techniques and multi-physics simulations.
The high-strength and low-density properties of metallic lattices have found applications in many fields. During the process of laser powder bed fusion (LBPF) 3D printing, missing struts and defects can occur that affect the mechanical behavior of the printed lattice. To ensure quality, researchers said, scientists typically perform a post-build inspection, which takes time and is not always possible, especially with complex builds. To address this issue, an LLNL team has investigated the ability to monitor build quality in situ to decide, on-the-fly, if the part will satisfy quality requirements.
The researchers monitored the printing of a metallic micro-lattice structure using a photodiode, a pyrometer — both of which measure light emitted from the melt pool — and thermal imaging. The team printed normal struts and intentionally defective ‘half-struts’ through the LBPF process, measuring the thermal emissions from the melt pool. The team then developed a method to use those thermal emissions to predict defects with high accuracy.
Looking into the Chelyabinsk event, one simulation at a time
On the morning of Feb. 15, 2013, a small asteroid exploded over Chelyabinsk, Russia, sending a loud shockwave and sonic boom across the region, damaging buildings and leaving around 1,200 people injured. The resulting meteor, with a diameter of approximately 20 meters (roughly the size of a six-story building), was one of the largest to be detected breaking up in the Earth's atmosphere in more than a hundred years.
A decade later, scientists from Lawrence Livermore’s Planetary Defense program are releasing details of their research of the airburst event. The team spent the last three years modeling and simulating the atmospheric breakup of the Chelyabinsk meteor. Their study underscores the important role material strength and fracture played in the breakup dynamics.
Though various research organizations have studied the Chelyabinsk event, LLNL scientists were the first to simulate the Chelyabinsk meteor in full 3D with a material model based on research data from meteorites recovered from the event. Unlike historical meteoric events, the 2013 airburst event was recorded on cell phone and security camera video from multiple angles and a 500-kilogram fragment was recovered from Lake Chebarkul shortly after impact.
Tough as knots
In the latest advance in nano- and micro-architected materials, engineers have developed a new material made from numerous interconnected microscale knots.
The knots make the material far tougher than identically structured but unknotted materials: they absorb more energy and are able to deform more while still being able to return to their original shape undamaged. These new knotted materials may find applications in biomedicine as well as in aerospace applications due to their durability, possible biocompatibility, and extreme deformability.
The knotted materials, which were created out of polymers, exhibit a tensile toughness that far surpasses materials that are unknotted but otherwise structurally identical, including ones where individual strands are interwoven instead of knotted. When compared to their unknotted counterparts, the knotted materials absorb 92 percent more energy and require more than twice the amount of strain to snap when pulled.
“The capability to overcome the general trade-off between material deformability and tensile toughness (the ability to be stretched without breaking) offers new ways to design devices that are extremely flexible, durable, and can operate in extreme conditions,” said former Caltech graduate student Widianto Moestopo, now at Lawrence Livermore National Laboratory.