Washington University: Researchers create novel electro-biodiesel more efficient, cleaner than alternatives

[OKIsItJustMe]

https://source.washu.edu/2024/11/researchers-create-novel-electro-biodiesel-more-efficient-cleaner-than-alternatives/

Researchers create novel electro-biodiesel more efficient, cleaner than alternatives

Researchers in the labs of Joshua Yuan, at the McKelvey School of Engineering, and Susie Dai, at the University of Missouri, used electrocatalysis of carbon dioxide to turn carbon dioxide into intermediates that are then converted by microbes into lipids, or fatty acids, and ultimately became biodiesel feedstock. The process is much more efficient than photosynthesis and uses significantly less land than soybean-based biodiesel. (Image: Kainan Chen)

By Beth Miller November 15, 2024

Vehicles fueled by diesel lead to substantial carbon emissions that are challenging to decarbonize. In 2022, diesel fuel use made up about one-fourth of total U.S. transportation carbon dioxide emissions and about one-tenth of total energy-related carbon dioxide emissions, according to the U.S. Energy Information Administration.

Joshua Yuan, the Lucy & Stanley Lopata Professor and chair of the Department of Energy, Environmental & Chemical Engineering in the McKelvey School of Engineering at Washington University in St. Louis, and Susie Dai, a MizzouForward Professor of Chemical and Biomedical Engineering at the University of Missouri, and their collaborators at Texas A&M University, have used electrocatalysis of carbon dioxide to create an electro-biodiesel that is 45 times more efficient and uses 45 times less land than soybean-based biodiesel production. Results of their work were published online Oct. 31 in Joule.

“This novel idea can be applied to the circular economy to manufacture emission-negative fuels, chemicals, materials and food ingredients at a much higher efficiency than photosynthesis and with fewer carbon emissions than petrochemicals,” said Yuan, who began the work with Dai at Texas A&M University. “We have systemically addressed the challenges in electro-biomanufacturing by identifying the metabolic and biochemical limits of diatomic carbon use and have overcome these limits.”

The team used electrocatalysis, a type of chemical reaction initiated by electron transfers to and from reactants on surfaces of catalysts, to convert carbon dioxide into biocompatible intermediates, such as acetate and ethanol. The intermediates were then converted by microbes into lipids, or fatty acids, and ultimately became biodiesel feedstock, said Yuan, who is also director of the National Science Foundation-funded Carbon Utilization Redesign for Biomanufacturing-Empowered Decarbonization Engineering Research Center.

…

https://doi.org/10.1016/j.joule.2024.10.001

[GoreWon2000]

1. Disel is one of the dirtiest burning fossil fuels

Decades ago, diesel particulates where classified as cancer causing.

[OKIsItJustMe]

2. Right. More immediately, diesel exhaust can cause heart attacks

However, displacing diesel immediately is practically impossible so, what shall we do in the meantime?

Shall we continue to burn petroleum-based diesel? Or, perhaps a less damaging alternative?

https://afdc.energy.gov/fuels/biodiesel-benefits

Biodiesel Benefits and Considerations
Biodiesel is a domestically produced, clean-burning, renewable substitute for petroleum diesel. Using biodiesel as a vehicle fuel improves public health and the environment, provides safety benefits, and contributes to a resilient transportation system.

Public Health and the Environment
The transportation sector is the largest source of greenhouse gas emissions in the United States. A successful transition to clean transportation will require various vehicle and fuel solutions and must consider life cycle emissions. Engines manufactured in 2010 and later must meet the same emissions standards, whether running on biodiesel, diesel, or any alternative fuel. Selective catalytic reduction (SCR) technology in diesel vehicles, which reduces nitrogen oxide (NOx) emissions to near-zero levels, makes this possible. The criteria air pollutant emissions from engines using diesel fuel are comparable to those from biodiesel blends.

Using biodiesel reduces life cycle emissions because carbon dioxide released from biodiesel combustion is offset by the carbon dioxide absorbed from growing soybeans or other feedstocks used to produce the fuel. Life cycle analysis completed by Argonne National Laboratory (PDF) found that B100 use reduces carbon dioxide emissions by 74% compared with petroleum diesel. The California Air Resources Board (CARB) reported similar values (PDF) from various sources for its life cycle analysis of biodiesel.

Air quality benefits of biodiesel are roughly commensurate with the amount of biodiesel in the blend. Learn more about biodiesel emissions.

…

[GoreWon2000]

3. No such thing as "clean diesel"

"Clean diesel" is another fossil fuel industry scam just like "carbon capture". They're nothing but excuses to keep burning the planet killing fossil fuels. My father was an engineer with more than 49 years of aviation and automotive engineering work experience and was a member of the Society of Automotive Engineers so such issues were part of my childhood

[OKIsItJustMe]

4. Uh, this is not "clean diesel" (like "clean coal.")

There are a multiple problems with petroleum-based diesel fuel. The one which people are beginning to appreciate is that burning it produces greenhouse gases which will kill us, another is the impurities (e.g. sulfur.) Electro-bio diesel would be essentially “carbon neutral,” and does not contain impurities (like sulfur.)

Here’s the thing, ;iquid fuels have a very high energy/volume ratio. You’re not liable to see battery-powered jetliners, or battery-powered cargo ships. Potentially, they can be converted to fuel-cells, but that requires fuel (it’s right there in the name) and you will not convert them all overnight. (Would that we could!)

The first stage of the Saturn V contained RP-1 (highly purified kerosene.) SpaceX's Falcoln 9 uses the same thing. The Starship booster uses methane. None of these things will be flown using electricity, but we can use electricity to make renewable fuels (without drilling oil wells.)

[GoreWon2000]

11. It's all snake oil

designed as an excuse to continue to burn the planet killing fossil fuels. BTW, your schooling and work credentials on this issue?

[OKIsItJustMe]

12. Please go back and read the OP - better yet, follow the links I provided

Vehicles fueled by diesel lead to substantial carbon emissions that are challenging to decarbonize. In 2022, diesel fuel use made up about one-fourth of total U.S. transportation carbon dioxide emissions and about one-tenth of total energy-related carbon dioxide emissions, according to the U.S. Energy Information Administration.

Cargo ships (for example) run on diesel fuel, and it is very difficult to transition them to something else. It will be decades before the entire fleet of them are replaced. This technology allows you to take renewable electricity (in the illustration, they are using PV solar panels) and generate diesel fuel without a drop of fossil fuel.

[GoreWon2000]

13. Curious, where are your schooling and work credentials on this issue?

Reading an article that's about justifying the continued burning of one of the dirtiest burning fossil fuels is not an example of expertise on the issue. My engineer father had bachelors and masters degrees in engineering, more than 40 years of aviation and automotive engineering work experience and was a member of the Society of Engineers. My engineer father's extensive schooling and work experience in engineering taught him how toxic all fossil fuels are for our planet and for the survival of humanity and why we must stop burning them. Cargo ships will eventually run on green hydrogen as will commercial airplanes because batteries carry too much weight and need to be charged much more frequently than filling these modes of transportation with green hydrogen..

[OKIsItJustMe]

14. You have obviously mistaken me for an opponent

Your father’s credentials are not terribly relevant.

My engineer father had bachelors and masters degrees in engineering, more than 40 years of aviation and automotive engineering work experience and was a member of the Society of Engineers. My engineer father's extensive schooling and work experience …

I will not resort to an “Appeal from authority.”

[OKIsItJustMe]

15. Powering transport with "Green Hydrogen"

… Cargo ships will eventually run on green hydrogen as will commercial airplanes because batteries carry too much weight and need to be charged much more frequently than filling these modes of transportation with green hydrogen..

They may very well eventually do this (I’m an advocate.) However, the technology to accomplish that is not available today (R&D continues) and, even if it were, we do not have time to either retrofit the various fleets, or replace them all.

Today, it is easier to replace their fuel with something which is either generated using electricity or (indirectly) from “green hydrogen” (like “green ammonia” for example.)

https://newatlas.com/energy/green-ammonia-primer-clean-fuel/

Indeed, in many ways, ammonia does a better job of storing hydrogen than hydrogen gas itself; H2 is notorious for leaking away through the metal walls of containers, for embrittling steel it comes into contact with, and for taking a lot of energy to liquefy at cryogenic temperatures. And then there's density: it may sound weird, but there's one and a half times more hydrogen in a gallon of ammonia than there is in a gallon of hydrogen, all else being equal.

Today, “bio-diesel” is (essentially) being made from food.

This is not sustainable, but it is seeing increasing use, converting large areas of forest into farms to produce it.


Like “green hydrogen” this is a way to generate fuel using electricity. Unlike “green hydrogen” it also uses CO₂, and creates an alternative fuel that could be used by today’s fleet. (It too requires R&D.)

https://source.washu.edu/2024/11/researchers-create-novel-electro-biodiesel-more-efficient-cleaner-than-alternatives/

“This research proves the concept for a broad platform for highly efficient conversion of renewable energy into chemicals, fuels and materials to address the fundamental limits of human civilization,” Yuan said. “This process could relieve the biodiesel feedstock shortage and transform broad, renewable fuel, chemical and material manufacturing by achieving independence from fossil fuel in the sectors that are fossil-fuel dependent, such as long-range heavy-duty vehicles and aircraft.”

[NNadir]

5. Wow!!!! We're saved! Of the 11300 CO2 to C2 electrochemical papers...

...published in the last ten years, according to Google Scholar - I usually come across 5 or 10 a month in my general reading - this is surely the bestest ever! Super! If say we cover all of Washington State with solar cells, except for little holes for the cities to break through, a divert the Columbia River to fill the big bioreactors with water and bugs to transform the C2 compounds to biodiesel, why all of our energy problems will be solved!

...and here I was thinking it would be difficult to do.

Simple!

Better I'm sure than all the benchtop renewable energy breakthroughs that have populated this forum in the 20 year period in which CO2 concentrations in the planetary atmosphere rose by about 50 ppm to be scraping 430 ppm.

We're saved.

[OKIsItJustMe]

6. No we're not

However, your nuclear-powered dreamworld is just that. (A dreamworld.)

Face facts, we will need fuels for the foreseeable future.

[NNadir]

7. Look, I fully recognize that nuclear power will not...

...save the world, mostly as a result of catcalls from people who address it from the prism of extreme ignorance, coupled with selective attention. It's very similar to the reason that Trump and not Harris is President elect.

As for what is and is not a "dream world" with respect to nuclear energy, the expenditure on nuclear energy this year world wide amounts to 67 billion dollars according to the EIA. The expenditure on so called "renewable energy" this year was 735 billion dollars, not including the 416 billion spent on energy storage and grids.

The combined wind and solar junk according to the EIA produced just 16 Exajoules of primary energy in 2023 combined with wind energy growing zero Exajoules from 2023 and solar by 2 Exajoules to 8. Fossil fuels are growing faster than this junk.

For more than three decades in an atmosphere of catcalls and vituperation from people who know as much about nuclear energy as Magats know about economics, nuclear energy has routinely and reliably produced between 28 and 30 Exajoules of primary energy every year, a figure that all the solar and wind crap ever built, all of which will be landfill in less than 25 years, have never, not once, matched nuclear by providing 28 or 30 Exajoules in as single year. And let's be clear, the main focus of people hyping this expensive and useless (in terms of addressing the extreme global heating that has left the plant in flames) was never and clearly still isn't about addressing fossil fuels. It was and still is about attacking nuclear energy.

It is clearly too late to recover much of what has been lost because of antinuke ignorance. The finest minds of the 20th century developed the technology and lesser minds trashed it in that century and this, so that it could not accomplish what it might have done.

I fully agree it's too late. What's done cannot be undone.

I have my own view of what is and is not delusional. Catcalls addressed at me to my mind define from whom I'm hearing, their intellectual and moral standing which I am in no way compelled to take seriously and for whom no respect can be asked of me.

I spent a lot of my time in the primary scientific literature both for professional reasons and personal concerns about the horror we leave for the future. Having done so, I'm a little jaded with respect to hyping benchtop grant fulfilling research as a "breakthrough" or even as being promising. In my career I've developed a sense about scale-up and the cheering for journalist readings of press releases about benchtop work is just bread and circuses, useful perhaps only a a narcotic salve to kill the pain of an ever more dire reality but otherwise of no value.

Thank you for your observations even if, sorry to say, I am precluded from taking them seriously.

[OKIsItJustMe]

8. Six words stopped nuclear power

Atoms for Peace: Atoms for Peace was propaganda. All the world knew about atomic power was that you could destroy cities with it. Eisenhower wanted people to see nuclear power as our friend! Hence the title of the movie, Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb. We were told that we could harness the mighty power of the atom to power our cities! We could have nuclear powered aircraft carriers, nuclear powered submarines, nuclear powered airplanes, even nuclear powered cars! Indeed, nuclear power would be “too cheap to meter.” We started building reactors, with little thought regarding what we would do with their spent fuel, or their reactor cores, and, they were not “too cheap to meter.” The “hype” was overblown.

Three Mile Island. The China Syndrome with its warnings of a “nuclear meltdown” had barely made it to the theaters, before we had one on our hands (although at the time, it was not acknowledged.) As the drama proceeded, people in the vicinity were greeted with “what if” maps in the local newspapers, portraying possible radiation exposure levels which bore a striking resemblance to maps of a nuclear detonation.

Virtually overnight, we stopped building new reactors, and existing ones were eyed as threats.


In the 1970’s we knew that fossil fuels were finite, and we knew that the “Greenhouse Effect” was a threat (although it was perceived as a distant one.) Gerald Ford started a campaign to make Solar Power practical. Jimmy Carter picked up his program, and expanded upon it, researching other forms of renewable energy sources as well.

Ronald Reagan came to town, and cut the R&D into renewable energy sources, and did not resurrect the nuclear industry. His answer was simply to produce and burn more fossil fuels.

In spite of Reagan R&D continued, although at a slower pace. Today, renewable energy sources can be installed faster and more cheaply than nuclear plants, and nuclear plants are not the climate panacea they are made out to be. (Back to propaganda again…)

https://www.sciencealert.com/here-s-why-nuclear-won-t-cut-it-if-we-want-to-drop-carbon-as-quickly-as-possible

25-Year Study of Nuclear vs Renewables Says One Is Clearly Better at Cutting Emissions
ENVIRONMENT 11 October 2020 By DAVID NIELD

Nuclear power is often promoted as one of the best ways to reduce our reliance on fossil fuels to generate the electricity we need, but new research suggests that going all-in on renewables such as wind and solar might be a better approach to seriously reducing the levels of carbon dioxide in the atmosphere.

Based on an analysis of 123 countries over a quarter of a century, the adoption of nuclear power did not achieve the significant reduction in national carbon emissions that renewables did – and in some developing nations, nuclear programmes actually pushed carbon emissions higher.

The study also finds that nuclear power and renewable power don't mix well when they're tried together: they tend to crowd each other out, locking in energy infrastructure that's specific to their mode of power production.

Given nuclear isn't exactly zero carbon, it risks setting nations on a path of relatively higher emissions than if they went straight to renewables.

…

In my opinion, nuclear fission likely has a role to play for some time. I believe it will be eclipsed by nuclear fusion (if we live long enough to deploy either.) In the meantime, we need to cut emissions as quickly as possible, and nuclear power just isn’t doing it.

Your utter rejection of renewable sources of energy, at every opportunity, in spite of the facts is simply irrational.

[NNadir]

9. Um no. What stopped nuclear power was selective attention driven by deliberate ignorance driven by propaganda.

Last edited Mon Nov 18, 2024, 08:43 PM - Edit history (1)

I don't live all that far from Three Mile Island. I've traveled through Harrisburg many times. There are about 50,000 people living there now, healthy and useful lives.

In the week of March 1978, when the Three Mile Island unit 2 melted, shortly before President Carter visited it, according to the data provided by the Mauna Loa CO₂ Observatory's Data Pages, the concentration of the dangerous fossil fuel waste carbon dioxide was 337.29 ppm.

Now clearly, anyone still carrying on about Three Mile Island 46 years, and 7 months and 21 days after the event, obviously doesn't give a shit about the readings at Mauna Loa today, but I do, because I'm fucking paying attention. Although this will no more distract anyone who spent more than four and a half decades carrying on with obsessive tripe, here are the numbers as of this week:

Week beginning on November 10, 2024: 423.60 ppm
Weekly value from 1 year ago: 421.00 ppm
Weekly value from 10 years ago: 397.33 ppm
Last updated: November 18, 2024

Weekly average CO2 at Mauna Loa

Let me see if numbers get any attention, not that I expect that certain parties who would rather google their way to opinion pieces from dumb journalists at popular science websites (as opposed to the primary scientific literature) to give a shit - clearly they don't - in the last 46 and a half plus years with continual whining about TMI, the concentration of the dangerous fossil fuel waste carbon dioxide has risen by 86.31 ppm. In the "percent talk" used by apologists for squandering trillion dollar sums, the concentration of fossil fuels, we've added another 26% to the already unacceptable levels of CO₂ that were present in 1978.

Anyone carrying on about TMI, I repeat, clearly doesn't give a shit. I'll add to that a remark about whining about a policy from the 1950's is even worse, more reflective of cultish indifference than even whining about TMI does. The fucking planet is in flames.

Now, I frequently post reference to the primary scientific literature, to a Lancet paper, giving the deaths from air pollution, about which people whining about TMI couldn't care less about.

It is here: Global burden of 87 risk factors in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019 (Lancet Volume 396, Issue 10258, 17–23 October 2020, Pages 1223-1249). This study is a huge undertaking and the list of authors from around the world is rather long.

In 1978, when nuclear plants were replacing coal plants, the plants did not have scrubbers to remove sulfur oxides or particulates; presumably they were even more deadly than the coal plants operating today about which antinukes couldn't care less. The modern paper gives a death toll of roughly 19,000 human beings a day, but let's round down to a 15,000 deaths a day to reflect the smaller population in 1978. With 17,037 days since March 28, 1978, this represents (conservatively) 255,600,000 million deaths.

Again, in the primary scientific literature, and not some idiotic opinion piece from a nominal "science journalist" at a website.

One of the world's most prominent climate scientists, with a colleague, calculated how much the maligned nuclear industry saved in terms of carbon dioxide, 61 billion tons.

Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power (Pushker A. Kharecha* and James E. Hansen Environ. Sci. Technol., 2013, 47 (9), pp 4889–4895)

Now, the scientific literature is not monolithic, nor should it be; it is not even free of fraud, although scientific fraud has never killed as many people as have died from the fraudulent carrying on about TMI for more than 46 and a half years.

As I read the scientific literature daily, seven days a week, probably at least 350 days a year, if not more, I can claim a modicum of critical thinking, which is why I understand that electricity to drive an electrochemical cell to carry out one of thousands upon thousands of papers on electrochemical cells to reduce CO₂ to make C₂ compounds, in this case, for bugs to eat to make biodiesel isn't about so called "renewable energy" at all. It's about electricity, a thermodynamically degraded form of energy most of which is generated by combusting fossil fuels.

Now.

Here's an opinion piece from a Taiwanese scientist and a Hong Kong scientist, open sourced, from Joule out of the Cell Press:

A Reliability Look at Energy Development Kuo, Way et al. Joule, Volume 2, Issue 1, 5 - 9

I'll quote liberally from it.

It refers to "Atoms from Peace."

...US President Dwight D. Eisenhower's speech “Atoms for Peace” to the UN General Assembly on December 8, 1953, initiated the commercialization of nuclear power plants in the 1970s, mainly in North America, Europe, and East Asia. According to the International Atomic Energy Agency (IAEA), currently 446 nuclear power units operate around the world, providing about 12% of the world's electricity.3 The operation of these nuclear units has dramatically affected the greenhouse gas problem. Nuclear power plants were responsible for removing around 64 Gt of CO2-equivalent from the atmosphere from 1971 to 2009.4 Climate change would have been worse otherwise...

I know...I know...I know...TMI!!!!!, TMI!!!! Much much worse than climate change and the deaths of a quarter of a billion people.

... One-third of the world's 7.5 billion people live barely above the poverty line, without or with extremely limited electricity resources, clean water, uncontaminated food, basic education, and medical services. As a result, these 2.5 billion people usually live shorter lives, about 50 years on average. But they are the ones who have to bear the consequences of air pollution created by the other 5 billion relatively affluent people on the planet.
These poverty-stricken and energy-deficient regions are plagued by diseases such as AIDS, SARS, Ebola, and Zika as well as other rarer viruses, which in turn spread to the other 5 billion residents who generated the air pollution in the first place. Human beings living in a contemporary environment behave in just the same satirical manner as the two giants in Rabelais' The Life of Gargantua and of Pantagruel, don't they?...

Fear of radiation killed people, radiation itself didn't at the big bogeyman at Fukushima:

... Since 2016, Taiwan's drive to abandon nuclear power, being forced to rely heavily on fossil fuels, has left Taiwan barely able to meet its electricity needs. On August 15, 2017, Taiwan suffered its worst blackout in nearly two decades. Around 6.8 million households and business users were affected for several hours. The power cut, which was due to a flawed supply replacement process, amounted to a 10% loss in Taiwan's generation capacity, far exceeding Taiwan's dangerously low backup power supply, which is only 4% of capacity that day.

Before the Fukushima nuclear power plant accident triggered by an earthquake on March 11, 2011, nuclear power accounted for more than one-quarter of Japan's power consumption. But after the accident, Japan decided to suspend operations so that safety inspections could take place. The country officially entered the “no nuclear power” stage on May 5, 2012, only to see smog return in Tokyo. At the same time, not a single person has died of radiation sickness from the Fukushima accident according to the latest UN report and the World Nuclear Association, updated in 2017. But carbon dioxide emission targets for 2011 have been missed, and a trade deficit has been reported for the first time in 30 years. Japan restarted some of its nuclear power plants in July 2015 because of need and in an effort to confront air pollution. Currently, there are five units in commercial operation. By 2030, the share of nuclear power in electricity is targeted to return to 20%–22%...

And then, a quasi moral statement with which I couldn't fucking agree more, including some words about thermodynamic reality in the face of the hydrogen idiots who've been prattling on even longer than the TMI obsessives:

...The biggest crisis we face today is the risk of misusing data. For example, long-term ignorance about air pollution and greenhouse gas emissions owing to the use of fossil fuels leads to more deaths and global warming. Similarly, effects may result from ignorance of the fact that water splitting into hydrogen requires more energy from the hydrogen carried, ignorance of the limitation of renewables with intermittent nature, such as solar and wind power, before the availability of viable energy storage techniques for very large capacity, and overexaggeration of the impact of nuclear accidents and waste.

It is true with the 9/11 terrorist attacks and the 3/11 Fukushima nuclear accident, as well as smog, environmental protection, national security, and so forth, that unreliable “human beings” are the source of most problems. The majority of disasters today are the result of self-packaged decisions. Honey-tongued decision makers quickly shrug off responsibility even if they are clearly accountable.

The challenge today is how to prevent the misuse of data and how to manage slogan-slinging politicians. Only then will we cease to see progress as double edged. Energy transition is not possible without global cooperation and international policy on decreasing the use of fossil fuels in both electricity generation and other types of energy consumption.

Truer words than the part I've bolded have seldom been spoken. I underlined the thermodynamic truth for the people around here and elsewhere, people who don't give a flying squirrel's ass about extreme global heating, who are working here and elsewhere to rebrand fossil fuels as "hydrogen," and just as contemptible, electricity as "renewable energy." Electricity isn't "green;" hydrogen isn't "green;" and tearing the shit out of the wilderness that remains for wind turbines and solar cells isn't "green" either.

The fucking planet's on fire, continents strain alternately under extreme droughts, extreme heat, and extreme floods, and still we hear the same fucking chanting I've heard, with ever growing disgust, TMI! TMI! Fukushima!!!!!! Chernobyl!!!

The world is falling apart, and one reason for it is a complete lack of sense or decency, and as the authors of the Joule paper point out, misusing data.

Have a wonderful day tomorrow.

[OKIsItJustMe]

10. I guess you don't bother to try to understand things you don't want to

I did not say that Three Mile Island was some sort of horrible nuclear wasteland. I too am quite familiar with Pennsylvania’s nuclear plants. (I am also familiar with the coal seam fires, and the piles of tailings. I know the depressing little mine towns, their ramshackle houses built right on the street, roof drains suspended above the sidewalks to empty onto the street. I know the larger ones, like Carbondale…)

Here’s what you fail to grasp, people realized that “Atoms for Peace” was a lie. They also realized that they had been lied to about the accident at Three Mile Island (I knew a family who lived in the area.)

When people realize they have been lied to, they tend to be distrustful. Prior to “Three Mile Island” I would say the iconic “cooling tower” (not unique to nuclear power plants) represented scientific progress, a source of pride of accomplishment. Following “Three Mile Island” people saw them as threatening.

It was irrational, but it’s also understandable.