Monthly Archives: July 2020

Hydrogen as an Renewable Fuel

The future of transportation, at least the clean air kind of transportation, will be powered by electricity. Fully electric cars are being manufactured by some companies most notably Tesla and most manufacturers have plans for them. Even big trucks such as semis are being developed to run on electric motors. Plug-in hybrids and simple hybrids utilize a combination of electric motors and Internal Combustion Engines (ICE) for greater fuel efficiency than straight ICE-powered vehicles.

Vehicles that use electricity for at least part of their motive power use batteries for onboard energy storage. These batteries can be charged from the grid for plug-in hybrids. Hybrids such as the Toyota Prius are charged on the fly by regeneration from braking or alternatively by charging from the ICE.

Under certain circumstances such as rail traffic, the electricity can be provided through the tracks or overhead wires. Depending on the country most to all rail traffic in Europe is powered by motors charged by overhead electric lines.

An as yet exploited alternative to batteries or electric lines are fuel cells powered by hydrogen. A fuel cell is a device which uses hydrogen as the fuel to be converted directly to electricity. The only product of the process is water.

Hydrogen as a fuel has several advantages. As noted it is “clean burning” the only product being water. Important for transportation is its very high energy density. For a given weight Hydrogen has about three times as much energy as gasoline and over 100 times as much as that stored in a battery used in electric vehicles.

Under normal conditions, what chemists call Standard Temperature and Pressure, Hydrogen is a gas but it can be pressurized to decrease its volume. The biggest drawback to Hydrogen as compared say to a fossil fuel is that it can’t be pulled from the air or mined from the ground, it has to be created. Currently, the cheapest way is to strip the Hydrogen from natural gas. Alternately, it can be made from water via a process called electrolysis.

If the energy to make the electricity needed is from wind or solar, it is a way of making a storable form of renewable fuel. And that is a really big area of research. Of course one can always just use solar/wind-generated electrical energy to do electrolysis, but there are inefficiencies.

Two areas of research are microbial biomass conversion and direct photocatalytic production. Microbial production of Hydrogen comes from engineered bacteria that produce Hydrogen when fed. If the feed is something such as fructose made from corn, then the process is renewable.

Likely the best method is the latter, photocatalytic production. Some materials, Titanium Dioxide is one example, when placed in water and exposed to sunlight cleave the water releasing Hydrogen and Oxygen. The problem is low efficiency. Intense research is examining a welter of more exotic materials that are of much greater efficiency.

Currently, Toyota is the only manufacturer selling a Hydrogen fuel cell vehicle. In the United States, they are for sale only in California and Hawaii, and even in these locations, Hydrogen fueling facilities are few and far between.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Coronavirus and Science

As a scientist, I find it difficult to rationalize how some reject knowledge gained by a simple process of being careful about how things come to be known. Science is not some arcane unyielding body of knowledge but rather a process of ensuring that what we learn about something represents reality. There are numerous definitions of science but my favorite comes from the Nobel laureate Richard Feynman: science is what we do to keep from fooling ourselves.

The value of wearing a mask and social distancing as an effective means of disrupting the transmission of a serious disease comes from an understanding of the germ theory as shown by Louis Pasteur around 1860. This is nothing new and certainly not political. One hundred and sixty years of medical wisdom supports the fact that disrupting the transmission of an infectious agent is the way to prevent the spread of the disease. In this case, the infectious agent, SARS CoV-2 (the virus), may be new but how to address it’s spread is not.

Covid-19 (the disease caused by the virus) can go away but not by magic, rather by an informed and compassionate public taking the right steps to break the chain of transmission. Here in the United States, a relatively ill-informed public took half-hearted measures and then abandoned them too soon. New cases are on the rise both here in Arkansas and across the United States. More people are becoming ill and more people are dying because too many reject science. Too many people are rejecting hundreds of years of medical wisdom.

The leadership and citizens of much of the technologically advanced world get it. Life in New Zealand is back to normal as they are free of any new cases of Covid-19. The member states of the European Union have a larger population but hundreds of times fewer new cases. Meanwhile here in the United States, we are see-sawing in and prematurely out of closing down businesses to prevent disease transmission.

There is a furious global effort to develop a vaccine to combat Covid-19, but that can take a year or more to properly develop, test, and distribute. This could be the solution but again, reluctance to accept science stands in the way. Polling shows that up to fifty percent of the public will reject vaccination.

There is a long line of scientists; Pasteur, Jenner, Koch, Hooke, Harvey, Paracelsus, Vesalius, and on and on, and many more. More modern medical luminaries such as Reed and Salk and up to the present – Dr. Anthony Fauci . They all have provided the knowledge as to how we should address the pandemic if we care.

There is no alternate host, no reservoir for the coronavirus, it only exists in active cases. Stop transmission, and the disease goes away. It really is that simple.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Sustainable Energy is Booming

By late in 2019, the combined electricity produced by grid-connected wind and solar photovoltaics represented 10% of the total production. And the share of these intermittent but sustainable energy sources continues to grow. Energy production from coal is in free fall, despite the current administration’s attempts to favor it.

A constant refrain from detractors is intermittent sources such as wind and solar require expensive backup when the wind isn’t blowing or the sun isn’t shining, and therefore can’t be a serious part our electricity production until such batteries or other energy storage systems are available. That however is just not the case. It is estimated that a national network of electricity production and distribution can utilize up to about 30% wind and solar without the need for additional storage to back up the intermittency.

Consider what happens when one of our local nuclear reactors goes down to refuel. Is there another reactor on stand by to make up for the power not produced during the refueling? No, of course not, there is plenty of “slack” in the system to make up for that not produced during the refueling.

Other factors help balance the power from wind and solar. Solar is well matched to demand. Demand is higher during the day when solar panels are producing, and lower at night when the power from solar panels isn’t needed. Without the input from solar panels, a power company may have to buy power from sources that are on standby. Some power companies utilize time-of-day pricing, charging less at night when power is relatively abundant, and more during the day when demand is higher.

Wind and solar also balance each other seasonally. As sunlight passes through the atmosphere light is scattered and less reaches the earth. The lower the sun angle the more atmosphere it must pass through. Solar panels are more productive in the summer due to the the higher sun angle. A higher sun angle means less scattering of the light and more sunlight striking the panels.

Conversely, wind turbines are more productive in the winter. There are two reasons. Wind is generated by temperature differences between locales and the differences are greater in the winter, hence higher wind speeds. Additionally, colder air is denser. More power will be generated by the denser air at a given wind speed.

One final balance is that the sun shines during the day (duh) so solar power is available during the day, but wind speeds are greater at night. Wind and solar are both intermittent but complementary, both daily and seasonally.

As intermittent energy sources grow there will be a need in the future for energy storage and that constitutes a huge area of research. Electrochemical batteries, pumped water storage, other gravitational energy storage systems, compressed air, flywheels, and on and on. The future will be powered by the wind and the sun, cleanly without the need for fuel, and without waste disposal issues.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Fungi, a Few Highlights

There are estimated to be some five million species of fungi, from deadly mycotoxin producing molds to gastronomic delights worth hundreds of dollars per ounce. From the fungus singularly responsible for the global alcohol industry to a fungus responsible for jock itch.

The defining characteristics include the fact that they are eukaryotes – they have a cell nucleus unlike bacteria and possess specialized organelles that allow for the “burning of fuel;” that is, combining oxygen with sugars to produce energy. They are all sessile – they can’t get up and move around nor do they use sunlight like plants. As absorptive heterotrophs, they gain nutrients by digesting food externally and then absorbing it. By this function alone they are very important in recycling plant and animal matter.

On the positive economic side, the arguably most important fungus is yeast, specifically of the genus Saccharomyces, or Brewer’s yeast. The global market for alcohol is one to two trillion dollars per annum. There is evidence of wine production dating to circa 6000 BCE in eastern Europe. A minor side product of brewing is a one-hundred-year-old product called Vegemite, a mixture of leftover brewer’s yeast and some flavoring – Australians swear by it.

Some fungi known as smut can cause damage to plants and especially stored grains. An interesting example that plagued medieval Europe is ergot, Claviceps purpurae. This fungus can grow on rye and related grains and when the infected grain is consumed causes a condition known as Saint Anthony’s Fire. Chronic low-level ergot poisoning leads to gangrene with damage to extremities whereas acute poisoning results in headache, spasms, disturbances of the GI tract, convulsions, and psychosis. During the middle ages in Europe whole communities would have been occasionally affected. The last know outbreak of St Anthony’s Fire occurred in France in 1951.

Alkaloids from ergot were later used to produce a semi-synthetic derivative known as LSD – the hallucinogenic drug made famous by Timothy Leary in the 1960s. Other hallucinogens are known to occur naturally in several different species of mushrooms, They were traditionally used during religious ceremonies.

The Aztecs consumed a mushroom known as Teonanacatl, Pslyocibe mexicana. In Siberia a mushroom called Fly Agaric, Amanita muscaria was similarly employed with a unique twist. In a Siberian ceremony the Shaman would consume the mushrooms, then because the active drug was not transformed, would serve his urine to acolytes. Drinking the urine produced the same effects as having consumed the mushrooms themselves.

Consumption of many wild mushrooms is capable of producing all sorts of untoward symptoms from minor GI problems up to an agonizing death. One edible, but it depends, mushroom is called the inky cap, Coprinopsis atramentaria. Consumption of this mushroom, common in both Europe and North America, is not a problem unless alcohol is consumed ant the same time or shortly thereafter.

The mushroom has a compound that interferes with the metabolism of alcohol. This causes a mildly toxic intermediate, acetaldehyde, which induces nausea and vomiting within minutes of consumption of alcohol. Not surprisingly another common name for this mushroom is tippler’s bane.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University. His website is Bob of the Ozarks,