Cars and Hydrogen

Is this love affair headed for destruction?

There is no doubt that we love our automobiles.  The earliest models ran on either steam or batteries.  Gasoline actually came somewhat later.  Why did we switch?

That happened because there is so much energy stored in gasoline.  We could drive dozens of miles without having to recharge our batteries or stop to stoke the fire and find more water to make more steam.

Of course it was fantastic to have cars whether they were steam, gasoline, or electric.  If you could find a suitable place to get up to speed you could go faster than a horse, and do it continuously, long after a horse would have had to reduce its speed due to exhaustion.

Gasoline just made it more convenient and even more durable.  Steam and batteries faded into history.

What goes around…

Now we have finally come full circle, haven’t we?  We’re back to electric cars because we’ve created new batteries with large energy densities so that you can drive hundreds of kilometres or miles before you have to find some place to plug in and recharge.  The new 100 kW battery pack in the Tesla X P100D will manage 483 kilometres/300 miles on a single charge and manage 0-100 k/h (0-60 mph) in 2.9 seconds.

In many cases we could simply change the battery out and replace it with a fuel cell.  Fuel cell systems are smaller and lighter than the heavy membrane-type batteries currently in use.

Of course battery-powered vehicles won’t be replaced by vehicles with fuel cells.  The convenience of a battery powered vehicle for people with short commutes is undeniable.  They’re clean, green, quiet, and cheap to charge.  And right now a kilogram of hydrogen (in this early testing stage) is selling for about US$10 per kilogram (2.2 lbs).  The price will come down as our hydrogen infrastructure improves so that it is more comparable with the price of gasoline.

In terms of energy density, a 4 kilogram tank of hydrogen (the normal size for a car) will provide about 500 kilometres (280 miles) of driving, so that would cost you US$40.  It can be refilled in just 3–5 minutes, about the same amount of time as filling a car with gasoline.

So now it is fast, comparably priced, and provides a good range for a vehicle…what’s left?  Oh yes… the Hindenburg…

Safety

hindenburgThe lighter-than-air craft Hindenburg comes up in almost every conversation about hydrogen.  People like to point to the 1937 disaster as an example of how dangerous hydrogen is.  The truth is that probably nobody was burned by the hydrogen.

Burns were traced to the aluminiumised fabric of the outer envelope which supposedly protected the ballonets of hydrogen within, and to the spilt and splashed diesel fuel used to power the engines.  What most people don’t know is that 61 of the 97 passengers survived.

Despite still being 100 metres/300 feet in the air, the (presumed) lightning strike from the thunderstorm that started the fire in the tail section, allowed the rear section to descend to the ground briskly, but not fatally so.  People do not survive a 30-storey drop ordinarily.

The flames quickly flashed the length of the ship as the Hydrogen escaped and burned.  To be burned by the hydrogen a person would have to above the gas cells because hydrogen only goes up, never down.

Is It Safe For Cars?

hydrogen-car-burningActually, there’s more stored energy or explosive power in a car’s tank of gasoline than there is a tank of hydrogen.  More importantly, gasoline splashes, and pools, and volatises (evaporates) whereas Hydrogen goes straight up.

In a study performed by the University of Miami, in 2001, a leak-simulation test was conducted.

As you can see, the gasoline powered car (on the right), was destroyed within a minute.  The hydrogen powered car with a leak (on the left) was left completely unharmed.  It’s just basic physics: gasoline drips, pools, and collects, awaiting its opportunity to expend all of its stored energy.  Hydrogen just wants to escape.

Batteries for electric cars are probably very safe, much like hydrogen.  Still, given the choice, I would rather be in an accident with a hydrogen fuelled car, than either a gasoline or battery type.  Gasoline is obvious, but a shorted-out battery large enough to power a car could melt and fuse releasing a lot more energy.

The Takeaway

There are a lot of reasons to pick the various types of Power Systems for vehicles.  It might be the availability of fuel; how much it cost to move from point A to point B; the environmental impact of your choice; or whether the vehicle has the capability to take you from your point-of-origin to your destination, and then back again, without unnecessary complications about finding fuel.

Within the next few years we will probably phase through from gasoline, to pure electric, and then finally to hydrogen.  Good old hydrogen is the most abundant element in the Universe, and aren’t you tired of hearing the same old story about “running out”?  Me, too…

External links

National Fuel Cell Research Center

Fueleconomy.gov – page about hydrogen cars

Bilforsikring –  Elbil forsikring

Hydrogen Cars Insurance

Energy Efficiency in Hydrogen Based Vehicle Systems

The 21st century gave birth to a race all humankind takes part to. Like it or not, the reign of fossil fuel is about to end with a large bang. Engineers, scientists and pioneers of technology developed viable alternatives with two goals in mind:

  1. Provide a virtually non-depletable source of energy
  2. Make sure said-energy is clean, or at least cleaner than fossil fuel

Still, what’s wrong with fossil fuel, as long as there’s still some left? In short words, greenhouse emissions. On a worldwide scale, humanity is getting around 80% of the energy it requires by burning fuel, according to World Bank stats. While the percentage may have dropped since the 60s, the quantity of fuel burnt increased dramatically, thus raising the level of greenhouse emissions. Carbon Dioxide (CO2) is the main element of the heat blocking blanket our Earth has been covered with and vehicles produce tons of it every single day. A study done by EPA shows 6,780 metric tons of CO2 have been released in the air in 2014.

How does hydrogen come into play?

Unlike conventional heat engines, eco-friendly machines can electrochemically transform hydrogen in usable electric energy. The energy resulted is used to power electric motors, for example in consumer vehicles.

The entire process is possible thanks to one or more fuel cells. A fuel cell uses a polymer electrolyte membrane (PEM) to harness electric power. The system is composed of a cathode and an anode sunk in an electrolyte, all covered on both ends by energy harnessing bipolar plates. In the anode, the hydrogen is separated into protons and electrons, while a membrane allows only protons to move further. In the meantime, electrons travel on a separate route towards the cathode, creating electricity through their movement. Once they return from the trip, hydrogen electrons react with oxygen and hydrogen protons, generating heat that can be further used by other systems.

Hydrogen cell efficiency in transportation

For the moment, hydrogen cells are not being used on a full scale in the automotive industry. The first ever commercial vehicle to run solely on hydrogen is the 2015 Toyota Mirai. It runs solely using hydrogen cells and exhausts drinkable water.

Of course, all hydrogen based cars use electric motors to generate thrust. There are various advantages of an electric engine compared to a standard fossil fuel unit:

  • Higher efficiency (60% electric vs 35% gasoline/diesel)
  • Instant torque over a wide RPM range
  • Removes the need for a geared transmission
  • Low maintenance costs (fewer elements requiring replacement)
  • Less noise

Hybridization – path to cleaner air and cheaper transportation?

It is pretty obvious that hydrogen fuel cell vehicles are better from almost any point when compared to traditional fossil fuel cars. They indeed allow for a cleaner air especially within cities where the exhaust fog is a serious issue in the last decade. Exhausting just water is a main plus when working in this direction.

It also needs to be mentioned that current fuel cell vehicles can achieve ranges of around 400 miles before needing to be recharged. And, compared to electric vehicles that rely on batteries to work, filling a tank of hydrogen takes just as much as it takes to fill one with gasoline. However, Tesla CEO Elon Musk considers hydrogen cars as being silly. What could be the reason?

First of all, it is true that creating electricity from hydrogen takes a lot more in account than simply delivering it to a set of batteries. With hydrogen, atoms must be separated in protons and electrons, then reunited and then finally exhaust the resulting water. Even more, it is a known fact that fuel cells heat up more than you’d want to. It’s a prime reason why Toyota Mirai is using large air intakes on the front fascia, to dissipate the heat.

Furthermore, when compared to fully electric vehicles, hydrogen cars aren’t all that cheap in terms of fuel. It costs around $40 to fill a tank with hydrogen, lasting for around 350 miles, in case of Honda Clarity. On the other hand, according to Tesla’s calculator, it costs just around $16 to charge your vehicle for 400 miles. Of course, it will take 90 minutes to do that.

Conclusion – Do Hybrid Vehicles present a Viable Future?

Someone has to admit it: Elon Musk’s statement on hydrogen vehicles only last as long as the current hydrogen infrastructure and technology does not advance. However, given the amount of research and development done in the field, hydrogen vehicles may very well become a popular choice along consumers, ensuring breathable air and lower costs.

Hydrogen: What goes up…goes up

Hydrogen is so light that the Earth’s gravity cannot hold it.  It wanders up to the top of the atmosphere where it escapes like a molecule of steam coming off of boiling water, or where it is simply eroded away by the solar wind.  Hydrogen loves to combine with other things though so there’s plenty of it bound at the molecular level.  Most notably of course it is bound up with oxygen to make water.

Watts up, Doc?

All of the energy we use comes from hydrogen.  Of course, it may have been created using hydrogen millions of years ago and sequestered somewhere (say as fossil fuels, or radioactive elements buried in the soil), but without hydrogen nothing else would exist.

Across Europe incoming solar energy (insolation) ranges between 2.75 and 5.44 kilowatts per square metre, annually.  In North America that range falls between 2.87 and 5.89; in Australia, it runs from 4.17 – 6.46 kw/m².  To put that all into perspective, the amount of energy we receive on our planet in just one hour exceeds the total amount of energy all of humanity uses in one year.

Most of our daily energy comes from the Sun.  It drives our weather system, keeps us warm, powers our waterfalls, solar collectors, wind turbines, and it concentrates its energy in food that we eat and feed to our domestic animals.  Without the only continuously operating hydrogen-powered nuclear fusion reactor within 4.36 light years, everything we know would grind to a complete halt.

Light of my Life

Liquid hydrogen is the lightest liquid.  At -250° C one litre of the substance has a mass of only 67 grams, as compared to water which is 1000 grams per litre (the de facto standard).  Part of the explanation for this is that hydrogen is the only element which can exist without a neutron, essentially halving its mass.

It IS Rocket Science

This is also why it makes such a great rocket fuel.  The U.S. Space Shuttle used hydrogen and oxygen to power its main engines in a ratio of 1:6 by mass, respectively.  The external tank held 106,000 kg of hydrogen and 629,000 kilograms of oxygen.  The difference in volume is almost reversed, with the heavier oxygen being only 553,000 litres, but the lighter hydrogen requiring 1,497,000 litres of space.  Consequently, the exhaust gas of the space shuttle main engines was environmentally friendly steam.

Solid hydrogen is also the lightest solid at only 86 grams per cubic litre.  If we could actually manufacture that much, it would take almost 12 litres of solid hydrogen to attain a mass of one kilogram.  Experiments in 2016 at 325 GPa (gigapascals) produced Phase V hydrogen between diamond anvils, but at that pressure the gap between the anvils was too small to get a conductor inside to see if it conducted electricity and if it was therefore a semimetal.

One GPa is equal to 9,870 Earth atmospheres.  325 GPa would equal 3,207,500 atmospheres.  In one experiment they believe they reached 388 GPa (3,829,560 atmospheres).  They hope to attain ~425 GPa in the next iteration and create a true metal of hydrogen.

It is not certain, of course, but it is theorized that hydrogen can be a true metal, but only at pressures normally found at a planetary core.  Experiments are being undertaken to hopefully find the VI (sixth) phase of hydrogen, which should be metallic.

If they manage to create it, scientists suspect that it will be a superconductor at room temperature, or possibly exist as a superfluid that defies gravity.  If it retains both states of superfluid and superconductor, which scientists have put forward as a possibility, they will have a completely unknown substance with contradictory properties on their hands.  Superconductors conduct, naturally; superfluids are insulators.  What will we get?

It’s Everywhere

Hydrogen is about 11% of everything biological.  Naturally that includes water which accounts for a large percentage of its presence, but it also includes fats, proteins, starches, sugars, or just about any other biological material you can name.

We actually go out of our way to add hydrogen to certain foods.  Rendered fats from meat processing were treated with hydrogen, or hydrogenated.  This turned a liquid fat into a solid and it could be used to make flakey, non-elastic pastry in the form of shortening.

Later, in the mid-20th century, we began hydrogenating perfectly clear vegetable oils, and they had the advantage of not requiring refrigeration, in a time when refrigerators were rare.  The Crisco /Cookeen/Copha generation was born.

Just For Fun

If you want to flummox your friends you can refer to hydrogen by its less common name protium (sometimes specified as 1H), named thusly because it has one proton and no neutron.  In the rare case where hydrogen obtains a neutron, we then call it deuterium (2H), and in an even rarer instance, if it acquires two neutrons, that isotope is called tritium (3H).

Keychain Amusement

Tritium is radioactive to a very small degree, and is often sold as semi-permanent light source to hang on your key chain.  Its specific radioactivity is so low that the glass vial that contains the tritium is more than adequate to shield the radiation.  It does make it easier to find your keys in the dark though, and the light in the vial is likely to last for a decade or more (tritium has half-life of more than 12 years) before it starts to fade.

No Small Matter

The only antimatter we have ever created was made at CERN, home of the Large Hadron Collider (LHC), and it was anti-hydrogen.  We could make that because all it requires is an antiproton and a positron, which are reasonably easy to come by in a particle accelerator (albeit somewhat expensive to make).  The reasonably small sample was maintained for 17 minutes.

Quite Illuminating

Before we had electric street lamps, night time illumination was most often provided by burning hydrogen gas.  There were alternatives, of course, such as carbon monoxide, acetylene, methane, natural gas, and coal gas, but hydrogen was relatively easy to produce.

The Takeaway

Don’t worry about running out of hydrogen.  We have a lifetime supply right here on our planet.  When it floats up to the sky it doesn’t necessarily escape.  Molecular hydrogen, H2, on its way through the ozone layer, often encounters monatomic oxygen, and joins with it, creating a heavy molecule of water that eventually makes its way back down to Earth.

Just 5 kg of hydrogen will let you cover more than 500 kilometres/300 miles in a full size car.  Hydrogen is currently selling at $10 per kilogram but as the infrastructure builds up, that is expected to drop.

Household fuel cells are available from a limited number of respectable manufacturers now.  They all have their good and bad points.  Some will only run on purified hydrogen; some will not operate below freezing temperatures; some fuel cells can operate on a combination of methanol and water which is far easier to acquire them pure hydrogen.  Others can run on propane or natural gas if you add a chemical reformer to the system.

Check out the options before you jump on board, and remember the technology is always changing.  Someone might invent a system that is just perfect for you, if it doesn’t exist already.  Keep aware of developments and one day soon you can be a 100% green energy user.

The Power of Hydrogen

You don’t need a Ph.D. to understand pH
Everybody who studied high school chemistry knows that pH stands for “Power of Hydrogen”.  What they may not know is that the actual notation was created by Søren Peder Lauritz Sørensen away back in the year 1909.  His original notation included the lowercase “p” and the upper case “H”, but the second letter was written as a subscript so it looked like this: pH

moleNowadays of course we all use the standard notation pH, so that we make consistent references and avoid confusion.  So, what are we discussing when the pH symbol is bandied about?

The power of hydrogen describes the level of hydrogen activity in a process.  Normally, in a sample solution, when performing a direct measurement, we would use electrodes that are designed to be sensitive to the concentration and activity of hydrogen ions.

ernst-equation

 

 

 

At this point I could explain what a mole is, or maybe attempt to help you fathom an Ernst equation, but there is a much simpler way to avoid both of them.

Litmus Paper & pH Test Strips

At the very beginning of the 14th century (1300 C.E.), a Spanish doctor named Arnau de Vilanova discovered that the pigments called litmus, which could be extracted from certain lichens, when put into solution, would detect changes in acidity and alkalinity.  When absorbent paper was exposed to the solution and then dried, small pieces could be dipped in a test solution to determine its state.

He apparently possessed a brilliant mind, and an excellent reputation as a doctor.  Among his clientele were three Popes, three Kings, and many rich elite whom he cured of seemingly intractable illnesses.

What are we testing exactly?

Chemical solutions have basic or acidic properties determined by their ability to take up or donate a hydrogen ion, respectively.  When hydrogen loses its electron, it has a net positive-charge; that means, quite literally, that it is a naked proton, and it really seeks to join with something in order to get back into a stable state.

When we use a pH test strip we are measuring the ability of the test substance to exchange a proton, and which direction that proton goes.  The speed of the reaction in the test strip determines the strength of the acidity or alkalinity.  Robust reactions will take place at the extreme ends of the scale, closer to 1 or 14.  Less powerful reactions will be closer to 7 (neutral).

Testing…Testing…1…2…3

If you need to test a gas (e.g. ammonia vapour [NH3], which happens to be alkaline) simply wet the litmus paper with plain water and expose it to the gas.  The gas will dissolve into the water and then react with the litmus providing the colour change.

The pH scale is considered neutral, as with distilled water, with a value of 7.0; it is acidic at 6.9 or less and alkaline at 7.1 or more.  The scale is logarithmic, meaning that an alkaline solution that measures 8.0 is only 1/10th as strong as one that measures 9.0, which is only 1/10th as strong as one that measures 10.0, etc.  The same is true about acids, such that a reading of 5.0 is ten times stronger than 6.0, and 4.0 is ten times the strength of 5.0.

In the early days of chemistry (when it was still called alchemy), actual values were not known; if you knew which state it was, nothing more was required.

Very strong bases can surpass the supposed “top” of the pH scale at 14.0.  Strong acids can also pass into negative numbers instead of stopping at 1.0.  The numbers 1–14 are simply a convention—just because a measuring ruler has a fixed length doesn’t mean that nothing longer than the ruler exists.

Litmus comes in two colours, red and blue.  Red litmus can be used to detect alkalinity (base), and blue can detect acidity.  By combining them you can create a neutral purple litmus paper that can detect both states but only up to 8.3 for bases and down to 4.5 for acids.  Stronger bases and acids provoke no additional colour change.

Modern times

Nowadays, of course, we demand and need much greater accuracy for measuring both chemical states.  By using different reagents we can achieve much more precise readings with these paper strips rather than resorting to ultra-sensitive, electrode-based physical measurements.

A brew master creating a wort from which to make beer wants to know if it has become alkaline.  S/he can then add citric acid to bring it back to a neutral state.  Paper strips are faster and easier than collecting a sample, taking it to a laboratory, and consuming time during which the wrong chemistry might kill your enzymes or your yeast.

  • Bromothymol blue turns yellow/blue for values between 6.0–7.6;
  • Methyl orange shows red below 3.1, and yellow above 4.4;
  • Methyl red responds (red to yellow) between 4.4 and 6.2 ;
  • Methyl yellow (red/yellow) responds between 2.9 and 4.0;
  • Nitrazine (yellow/blue) changes between 4.5 and 7.5;
  • Phenolphthalein turns bright pink at values greater than 8.3, and it is otherwise uncoloured;
  • Universal indicator is made with multiple components so that it can indicate over the entire traditional range of 1–14 (albeit with somewhat reduced accuracy)

ph-indicator-chartThis chart gives an idea of chromatic responsiveness of several reagents.  Of course there are others that are not included here.  The centre strip that is half red and half purple shows the original litmus responsiveness in comparison to the greater accuracy of 11 other types.

So…what are you doing after class?  Want to exchange protons?