Are Advanced Biofuels for Airplanes Ready for Takeoff?

The first in a two-part series on advanced biofuels.

In 2008, a group of airlines came to Boeing Co., the world’s largest aerospace company, with a big problem. At that point, the United States, under President Obama, was instituting policies to fight climate change. One of them involved cutting emissions from jet fuel.

A year earlier, bipartisan support from Congress had given the new administration what seemed to be a powerful new tool to do it, a law calling for “advanced biofuels.” It promised to be a new category of fuels that would reduce greenhouse gas emissions by at least 50 percent compared with petroleum-based fuels. It was aimed at the transportation sector, second to only electricity generation as the biggest emitters of CO2.

At the time, solar and wind power were already beginning to reduce power plant emissions, and the general assumption was that within 10 years the auto industry would begin to reduce its share of the transportation problem by producing electric cars. But the airlines worried that there was no way to use solar and wind to power commercial airplanes. Electric airliners weren’t on the drawing boards.

“They said, ‘Hey, we need help. We can’t do this on our own.’ And we said, ‘Yep, we can do that,’” recalled Darrin Morgan, Boeing’s chief strategist for creating new aviation fuels.

As a major U.S. exporter that has dealings with over 150 countries, Boeing had worked with airlines in the development of more fuel-efficient aircraft and better flying practices. Now it helped form and lead the Sustainable Aviation Fuel Users Group (SAFUG). It currently represents 27 airlines that consume one-third of the world’s jet fuel.

This was a step completely outside the global reach of Boeing or the world’s airlines: New aircraft fuels that met greenhouse gas reduction targets had to be developed and tested to meet tough aircraft standards. They could not freeze and had to be powerful and safe enough to run standard jet engines and use existing fuel delivery systems. Another goal was that airline passengers would not sense any difference in performance.

“We were trying to create a new industry that does not exist in the way we need it to exist,” explained Morgan, a former financial expert who was brought into Boeing because he was familiar with biofuels.

Finding low-carbon biofuels that can meet the requirements of the airlines, environmental groups and governments has undergone a long, lumbering takeoff. But, he said, he sees it as a step that’s beginning to happen.

Advice has come from many places. Environmental groups, worried about the sources of new fuels, rejected proposals to make biofuels out of trees. They were particularly worried about destruction of rainforests to create palm oil plantations. Social groups were unhappy about making advanced biofuels from food sources, such as corn, or on land used for food crops because a growing population will need more food.

Boeing and other SAFUG members also worked with another group. The Roundtable on Sustainable Biomaterials (RSB) was formed to include representatives of environmental, farm and social groups as well as experts from companies that make aircraft and jet engines. The idea was to forge a consensus for one standard of sustainability, not dozens.

“We sent a signal to the market very early that says we’re going to set a high bar. We said, ‘Folks, if you want to serve our industry, you need to meet that high bar,’” explained Morgan.

ENTER THE FINNISH PIONEER

There is a lot at stake in this.

Airlines produce about 2 percent of the world’s greenhouse gases. If the industry does not succeed in reducing its emissions, they are expected to grow to 3 percent by 2050.

In retrospect, Morgan thinks that the peculiarity of the airlines’ dilemma turned out to be an asset in drawing support for clear standards and new ideas.

“That was the beauty of not having an incumbent industry. There was none for biofuels, so we could make it the way we wanted from the beginning.”

Flight tests that followed showed that some of the most promising results came from Neste Corp., a company that was formed in 1948 as the state-owned petroleum company for Finland. In 2005, it became focused on a process that made diesel fuel using fatty acids and oily agricultural residues that included palm oil.

There was a large market for cleaner fuels in Europe, and Neste soon dominated it, making diesel used for trucks and cars. After being attacked by Greenpeace and other environmental groups, Neste began to modify its process. It agreed to phase out the use of palm oil, which is used for a variety of foods, and rely mainly on non-edible vegetable and animal wastes and residues to make what the company calls a “hydrotreated vegetable oil,” a product that closely resembles kerosene.

Working with Boeing and other members of the RSB, Neste came up with what is called a “drop-in” fuel that can be used in jet and turboprop engines. So far, according to Neville Fernandes, general manager for Neste in the United States, it has been successfully tested in 1,200 commercial flights.

What makes Neste’s fuel different from other competitors in the race to develop a bio-jet fuel is that the company already operates two refineries that make biodiesel for it, so it can quickly scale up and produce much larger quantities of jet fuel that can, according to the company, cut an airliner’s greenhouse gas emissions from 40 to 90 percent.

“It is definitely fair to say that Neste is a pioneer,” explained Boeing’s Morgan. “They took a big risk and deserve a lot of credit. They bet a large percentage of their company on the future of renewable fuels at a time when a lot of people were not making that bet.”

The hurdle that remains is called ASTM International. It was formed in 1898 as the American Society for Testing and Materials, and its first decision was to approve the steel used for rails by the Pennsylvania Railroad. It has since become international and has offices around the world that help set health, quality and safety standards for over 12,000 products.

Boeing and other aircraft and jet engine manufacturers have formed an ASTM committee to decide whether the fuel from the Neste process can be used globally for making low-carbon jet fuel.

THE END OF “BIOFUELS 1.0”

If ASTM approves, then the pool of renewable jet fuel will grow from a tiny 2 million gallons to a potential 2 billion gallons annually.

That’s not nearly enough to fuel the entire global airline industry, but, as Morgan explains, “it’s really an important step because it gets us out of the experimental phase and gets industries into large quantities at cost-competitive prices.”

An enlarging market, he hopes, will encourage more oil refiners and other companies to get into the business. It will also mark the end of what Morgan calls “Biofuels 1.0,” a risky period for governments, innovators and investors who assumed low-carbon jet fuels were a venture that would promptly take flight. Unlike Neste, several companies that have tried to make biofuels have crashed into bankruptcy. Others have made sudden shifts into products that don’t have to fly.

One of these survivors is Cool Planet Energy Systems, a Greenwood Village, Colo., firm that made a splash in 2009 with a technology called pyrolysis that can heat farm wastes, wood chips and nutshells in the absence of oxygen to create fumes that are then passed through a catalyst to make a liquid biofuel. “You don’t have any further refining or upgrading processing. It’s a ready to use liquid fuel. You just have to blend it together,” explained Wes Bolsen, the head of business development for Cool Planet.

The process also resulted in a dirtlike waste called char.

According to Bolsen, the process attracted investments from three major oil companies and won a $91 million grant from the Department of Agriculture. The potential feedstocks to be used by the company to make renewable jet fuel seemed unlimited.

“There are 42 million acres of beetle-killed trees in the northern Rockies. Those trees are going to fall down and rot and turn into methane, which is much worse than carbon dioxide,” he said, noting that by turning wood chips into biofuel, his company would actually be reducing greenhouse gases from the atmosphere.

Cool Planet built a pilot plant that worked, but it never got to the point where it could begin selling a biofuel. Its investors balked at raising the hundreds of millions it needed to build the first commercial-sized facility.

“The hardest thing to do is to get the first commercial-scale plant. It will be the most inefficient plant ever built because you’re going to learn from it,” explained Bolsen.

To stay in business, the company quickly needed a product to sell, so it turned to the char, the waste left over from pyrolysis. The char was branded “Cool Terra,” which the company describes as “an engineered biocarbon designed to improve soil health.” It is a soil additive that Cool Planet now markets in 48 states.

According to Bolsen, it has become popular with golf courses and nurseries that grow tomatoes and strawberries.

Cool Planet says it has raised $30 million and is building a plant in Louisiana that is designed to produce the char. Bolsen explained that it may not be ready to carry out the company’s dream to produce a biofuel. “You’ve got to do this step-wise,” he said.

Another survivor that managed a soft landing was Solazyme, a San Francisco startup that developed a biofuel from algae and sugar that seemed to hold promise until the company’s stock price began to crash last year. Then it transformed itself into a company called TerraVia Holdings Inc., which sells algae-based oil for cosmetics and food products.

At least a half dozen companies followed the trajectory of KiOR, a high-flying Pasadena, Texas, company that took off in 2007, briefly enjoyed a valuation of $1.5 billion for its process to turn wood chips into biofuels, failed to live up to its production estimates, and then crashed into a messy bankruptcy in 2014.

Then the attorney general of Mississippi—selected as the home of KiOR’s first commercial plant—called it “one of the largest frauds ever perpetrated on the state of Mississippi.” But others survived to meet the next challenge.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.

The Human Nose Knows More Than We Think

The smell of coffee may urge you out of bed in the morning, and the perfume of blooming lilacs in the spring is divine. But you do not see police officers with their noses to the ground, following the trail of an escaped criminal into the woods. Humans do not use smell the way other mammals do, and that contributes to our reputation for being lousy sniffers compared with dogs and other animals. But it turns out the human sense of smell is better than we think.

In a review paper published in Science last week neuroscientist John McGann of Rutgers University analyzed the state of human olfaction research, comparing recent and older studies to make the argument our smelling abilities are comparable with those of our fellow mammals.

McGann traces the origins of the idea that humans have a poor sense of smell to a single 19th-century scientist, comparative anatomist Paul Broca. Broca, known for discovering Broca’s area—the part of the brain responsible for speech production—noted that humans had larger frontal lobes than those of other animals, and that we possessed language and complex cognitive skills our fellow creatures lacked. Because our brains’ olfactory bulbs were smaller than those of other mammals and we did not display behavior motivated by smell, Broca extrapolated these brain areas shrank over evolutionary time as humans relied more on complex thought than on primal senses for survival. He never conducted sensory studies to confirm his theory, however, but the reputation stuck.

Scientists built on that tenuous foundation over the years, McGann says. Geneticists saw supporting evidence for humans’ limited olfactory abilities because we have a smaller fraction and number of functioning olfactory genes—but again this was not well tested. The idea that color vision took the evolutionary pressure off olfaction was later debunked when no link was found between that evolutionary development and smell loss. In addition, the size of olfactory bulbs, both in absolute terms and in proportion to the brain, does not relate directly to smelling power as scientists once thought.

Now that more sensory tests are being done, the results are mixed. Experiments conducted in previous decades have found humans are just as sensitive as dogs and mice to the aroma of bananas. Furthermore, a 2013 study found humans were more sensitive than mice to two urine odor components whereas mice could better detect four other sulfur-containing urine and fecal-gland odors tested. A 2017 study also revealed humans were more sensitive than mice to the smell of mammal blood.

One biological feature that does appear to be linked to smelling ability is the number of olfactory bulb neurons an animal has. This number is not linked to the size of the brain or bulb, however. Human women, whose sense of smell is more sensitive than men’s, have more olfactory neurons than the general population of mice but fewer than rats, and have much larger olfactory bulbs than both rodents. Men rank just below mice in olfactory neuron count, but all these species (as well as several other mammals) differ by just 10 million olfactory neurons or fewer.

The lack of a standard metric for scent is the main challenge, McGann says, in comparing absolute olfactory abilities across species. “It’s tempting to say humans are way more sensitive than mice at smelling human blood, and that sounds like a good ecological story,” he says. “But then you look at a whole range of other odors and realize that actually it just seems like there’s quite a lot of odors that humans are better at detecting than mice, dogs or rats, and other odors that we’re less good at detecting.” It’s impossible, therefore, to make sweeping generalizations about which species has the winning nose.

Gustavo Glusman, a geneticist at the Institute for Systems Biology, agrees. “Different species specialize in smelling different things, and it’s therefore very hard to compare [them] meaningfully,” he explains. He also points out the brain’s plasticity. “It is well known that when one function is lost, other functions become more nuanced,” such as increased hearing ability after vision loss.

McGann also says humans use smell much more than we generally assume. It affects how we experience food and take in our surroundings, and some of the most recent studies have looked at how body odor can reveal whether a person is anxious or aggressive, in addition to other details about the individual’s lifestyle. McGann thinks smell loss has been largely neglected as a medical issue because we underestimate its importance. He hopes to raise the profile of clinical olfaction and biomedical research in the field, he says, “so people who [have] lost their sense of smell can understand you really did lose something important. You’re not crazy that this is bothering you.

Charles Lindbergh Made Flight History 90 Years Ago, Changing Aviation Forever

Charles Lindbergh arrives at Le Bourget, near Paris, in his Spirit of St. Louis aircraft on May 21, 1927.

Credit: Hulton Archive/Getty Images

American aviator Charles Lindbergh was the first person to fly solo across the Atlantic Ocean on May 21, 1927, without stopping.
On May 20, 90 years ago, after completing several test flights and setting a transcontinental record, Lindbergh hopped aboard his Spirit of St. Louis plane at Roosevelt Field in Long Island, New York, and took to the skies for his 3,610-mile (5,800 kilometers) journey. On May 21, after soaring for 33 hours, 30 minutes, Lindbergh landed at Le Bourget Field near Paris, France. There, "he was greeted by a wildly enthusiastic crowd of 100,000," according to the Smithsonian's National Air and Space Museum, where the famous single-engine monoplane is on display.

"Our messenger of peace and goodwill has broken down another barrier of time and space," said President Calvin Coolidge of the exceptional flight

On April 30, 1928, Lindbergh flew the Spirit from St. Louis to Washington, D.C. — the craft's final flight — where he donated it to the Smithsonian.
The so-called Lindbergh boom, in which stocks for the aircraft industry soared and interest in flying skyrocketed, can be attributed to Lindbergh's transatlantic flight, according to the Air and Space Museum. For instance, in 1931, Swiss physicist Auguste Piccard and his assistant Charles Kipfer flew into the history books when they completed a 17-hour flight aboard a hot-air balloon; they were the first to ride a balloon into the stratosphere, ascending to 51,775 feet (15,781 meters).

Lindbergh did not always fly through smooth skies in his personal life. In March 1932, his 20-month-old son was kidnapped and murdered. (The FBI has a detailed account of the kidnapping, murder and investigation that led to the conviction of Bruno Richard Hauptmann, who was put to death by electrocution on April 3, 1936.)
In 1932, Amelia Earhart attempted, unsuccessfully, to become the first woman to take a nonstop solo flight across the Atlantic.

NASA Calls for Europa Mission Instrument Ideas

Credit: NASA, JPL-Caltech

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It's time for scientists to start thinking about the instruments they'd like to put on a potential life-hunting lander mission to Jupiter's ocean-harboring moon Europa, NASA officials said.
Yesterday (May 17), the space agency issued a "community announcement" about the possible Europa lander mission, telling researchers to get ready for an upcoming science-instrument competition.
"The possibility of placing a lander on the surface of this intriguing icy moon, touching and exploring a world that might harbor life, is at the heart of the Europa lander mission," Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate in Washington, D.C., said in a statement. [Photos: Europa, Mysterious Icy Moon of Jupiter] 
"We want the community to be prepared for this announcement of opportunity, because NASA recognizes the immense amount of work involved in preparing proposals for this potential future exploration," Zurbuchen added. 
NASA is already working on a $2 billion mission known as Europa Clipper, which will orbit Jupiter and study Europa over the course of dozens of close flybys. The main goals of that mission, which is currently targeted for launch in the early 2020s, involve investigating the structure and composition of Europa and gauging the habitability of its subsurface ocean.
In late 2015, Congress requested that NASA study the possibility of adding a lander component to the Europa project. The space agency has since concluded that the lander would be a separate spacecraft that would launch toward the Jupiter system on its own, not with Clipper. 
But the lander is still just a concept, not an approved mission. And its odds of getting off the ground are tough to gauge; the White House did not allocate any money to a Europa lander in its preliminary 2018 budget request, which was released in March.
However, NASA has money in its 2017 budget to fund the "announcement of opportunity" activities, agency officials said.  
The lander-instrument competition will be a two-step process. About 10 proposals will likely be chosen to advance to "Phase A"; the investigators behind those proposals will each get about $1.5 million to develop their ideas for 12 months, NASA officials said.
"At the conclusion of these studies, NASA may select some of these concepts to complete Phase A and subsequent mission phases," the officials wrote in the same statement. 
Potential instrument investigations, they added, must address one or more of the following scientific objectives:

• Searching for signs of life on Europa.
• Assessing the moon's habitability using techniques available only to a lander mission.
• Making lander-scale characterization of Europa's surface and subsurface properties.

The Triassic's Mystery Creature

The desert of Petrified Forest National Park. Credit: Brian Switek

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Dinosaurs are our ambassadors to the deep past. There’s hardly a better example of this fact than the Triassic. This stretch of time, the first chapter of the three-part Mesozoic epic, is often referred to as the Dawn of the Dinosaurs and ran from about 250 to 200 million years ago. This is despite the fact that dinosaurs were minor players in the Triassic drama. 
Sure, the first dinosaurs evolved by about 235 million years ago, but they were small and ecologically marginal animals for most of the period. The true rulers of the Triassic world were stranger creatures, many of them more closely related to crocodiles, and we are only just now becoming acquainted with the various species that we’ve let dinosaurs overshadow. The Triassic menagerie is far weirder than previous generations of paleontologists expected, and it’s only set to get more bizarre. Consider Kraterokheirodon.

Nobody knows what Kraterokheriodon is. The nature of this animal is totally inscrutable, joining the ranks of species like the Tully Monster in the ranks of fossil Problematica. But the two fossil teeth that represent this animal signal that there was something very odd shuffling around the Late Triassic of Arizona. Paleontologists Randall Irmis and William Parker, who named Kraterokheriodon in 2005, followed the fossil trail as far as they could.
The story of the “cupped hand tooth” started in 1946. It was in that year that geologist G.E. Hazen found an unusual tooth from the Triassic Chinle Formation of Arizona and gave the tooth to paleontologist Edwin Colbert. It was unlike any fossil found before, having a curved, shell-like shape. And that’s as far as the story of the tooth went until 1984, when Lynette Gillette found a similar tooth in Petrified Forest National Park. This was enough to reignite Colbert’s interest, although he couldn’t confidently assign the teeth to any known group. He was still studying them when he passed away in 2001.

A cast (top set) and fossil of Kraterokheriodon. Credit: Irmis and Parker 2005

Paleontologists Robert Long and Phillip Murry had an idea about who those teeth originally belonged to. In a 1995 paper, they proposed that the strange teeth were those of herbivorous protomammals called traversodont cynodonts. That’s why these animals had such a big role in the Petrified Forest episode of Walking With Dinosaurs. But Irmis and Parker didn’t find any direct support for this idea in their analysis of the fossil. (Hazen’s initial find is now only known as a cast, with the original missing, making Gillette’s find the only existing specimen.) The furthest they were able to narrow their identification of Kraterokheriodon colberti was Amniota, the major group that includes mammals, reptiles, and their closest relatives.
Kraterokheirodon is so bizarre, Irmis and Parker explained, that it’s difficult to understand how the unusual teeth even fit into the animal’s mouth. The fossils definitely are teeth – there’s enamel, dentine, a root, and other details which confirm this – but the certainties don’t go much further than that. The teeth don’t resemble those of lungfish, bony fish, or amphibians. And while the Kraterokheriodon teeth somewhat resemble those of some cynodonts, Irmis and Parker wrote, they are far larger and the superficial similarities may be a case of convergence rather than family relationships.
Ultimately, Irmis and Parker concluded, “the recognition of these teeth as a new and unique taxon is a reminder of how little is still known about the fauna of the Late Triassic Period.” That’s certainly understating how frustrating the lack of additional material has been. Based upon the size of the teeth, Kraterokheriodon must have been a large animal. This was not a small, delicate creature unlikely to fossilize. This was an animal that should have had similar fossilization potential to the phytosaurs, aetosaurs, dinosaurs, and other big-bodied fauna of Arizona’s Late Triassic. So where is it? The experts who explore the Petrified Forest continually ask themselves that question as they wander out into the Painted Desert. Somewhere out there, the key to Kraterokheriodon is waiting.   
This post was supported by my generous backers on Patreon. For details on how you can get an early view of new blog posts and exclusive natural history essays, click here.
Reference:
Irmis, R., Parker, W. 2005. Unusual tetrapod teeth from the Upper Triassic Chinle Formation, Arizona, USA. Canadian Journal of Earth Sciences. doi: 10.1139/e05-031 

America's Relationship with Volcanoes Changed Forever

Credit: USGS

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Many of you probably hadn't even been born when Mount St. Helens erupted on May 18th, 1980. You've never lived in an America that basically didn't expect exciting eruptions to happen in the lower 48. So it may be hard to imagine a time when most Americans were utterly astonished that one of our backyard volcanoes roared to life and caused a staggering amount of destruction, along with a substantial number of deaths, within an easy drive of major metropolitan centers.

Mount St. Helens in eruption on May 18th, 1980. Credit: USGS

This turned into one of the most well-studied eruptions in human history: American volcanologists had eyes on the mountain from the beginning, and were quick to get instruments to her slopes the instant she woke up. We were able to see the process of an eruption from the initial stirrings of magma deep within the ground, to the paroxysmal blast and its aftermath.
When the precursors were over and the volcano blew its summit on that sunny May morning, things were pretty much complete chaos. Nobody knew quite what was happening. Landmarks had been wiped out or drastically changed. It seemed to many observers that Spirit Lake was completely obliterated; the whole valley appeared to be exploding. It took a while for geologists to sort things out and figure out what happened, where, and why; what remained and what was gone; and what all those explosions in the river valley were all about.

Steam blasts pits in the debris and blast deposits in this view over Spirit Lake. Credit: USGS

 

When you look at this picture of steaming craters where Spirit Lake used to be, you can see why everybody was flummoxed. Turns out, though, that the explanation was fairly simple: when the summit fell, it brought down glaciers and chunks of that extremely hot cryptodome with it. The magma of the cryptodome was actually hot enough to turn the glacial ice, along with water from the rivers and lakes it buried, into steam, which then blew out craters in the deposits.

This moonscape is the result of pyroclastic flow deposits pocked with phreatic explosion craters. Credit: USGS

 

What remained looked lifeless, and in places, eerily like the moon. Geologists starting their initial post-eruption studies and the folks doing search and rescue were astounded by the change. It hardly seemed like the kind of devastation one average-sized volcano could deal.

Mount St. Helens on the morning of May 19th. She's been completely changed. Credit: USGS

 

We'd never seen a volcano change her shape quite so dramatically. We'd never seen a lateral blast of this scope in the continental United States. We'd never had to cope with mudflows pouring off a volcano's slopes, flooding towns and clogging up a major shipping channel. We'd seen plenty of eruptions in places like Alaska and Hawaii. We'd studied volcanoes worldwide. But Mount St. Helens was special. She was home-grown, she was easy to access even after she destroyed bridges and roads, and she's stayed active for decades, teaching generations of volcanologists what to expect before, during, and after a major eruption. We've never been able to study a volcano quite this conveniently before.
On this day, remember the geologists like David Johnston who gave their lives so that we could better understand these beautiful but dangerous fire mountains. Take a look through the archives here and read up on the prelude to the catastrophe, the cataclysm, and some of the immediate aftermath. Go through the series of photos from the 1980s we've collected. And if you haven't had a chance to see our very special volcano live, try to plan a trip to the Pacific Northwest to visit before she changes again.

David Johnston. posing with a gas detection instrument a month before his death. Credit: USGS

New Concrete Recipes Could Cut Cracks

There's a stretch of highway in Pennsylvania, along US-422. "And like every probably 20 feet you see a big pothole or cracking at the joint. Like everywhere. It was so bad." Yaghoob Farnam is a construction materials engineer at Drexel University in Philly. And this road is pretty much his worst nightmare. "Yeah and just imagine I was driving like 60 miles per hour, I could see, I could feel it, I was driving, I was so mad, like, 'what is going on with this?'" 
The culprit, he says, may be calcium chloride road salt, used to de-ice highways in the winter. Because calcium chloride reacts with a compound in concrete called calcium hydroxide to form something called calcium oxychloride. "It's a huge molecule that causes a lot of pressure inside concrete. And starts degradation of concrete." 
The solution? Novel blends of concrete that use cheap leftover materials from the coal and steel industries: fly ash, silica fume and slag. In his latest work, Farnam and his team created plugs of these experimental concretes, and submerged them in salty solutions—along with plugs of conventional concrete. Then they eavesdropped on any cracking with high-sensitivity acoustic sensors. And they tracked heat flow through the material, to monitor chemical reactions.
The results: concrete slugs made with ingredients like fly ash and slag held up remarkably well after more than a month. Whereas normal concrete was cracked to pieces in just a week. Their recipes are in the journal Cement and Concrete Composites. [Yaghoob Farnam et al, Evaluating the use of supplementary cementitious materials to mitigate damage in cementitious materials exposed to calcium chloride deicing salt]
Farnam says some states have actually started using this sort of concrete—because it's already known to make the material more durable against other factors, like corrosion of internal steel reinforcement. As for those cracks on US-422, and elsewhere? Farnam has another project in the works—to apply a bacterial slurry, which forms limestone when it interacts with salt, plugging up the gaps. But he says that work is still a ways…down the road.
—Christopher Intagliata