Saturday, February 26, 2022

A SHORT COURSE ON HYDROGEN

 SHORT COURSE ON HYDROGEN

There are many ways to isolate hydrogen.  The easiest is to electrolyze water…electricity is applied to 2 electrodes to split H2O into H2 and O2 gas. Basic high school chemistry lab.  It takes energy to do this, but energy is stored in the H-H molecules that are formed.  Oxidizing the hydrogen molecules releases that stored energy.  H2 can be sequestered and stored in a variety of ways…compressed gas, liquified, etc., and made available when the release of energy is demanded

When H2 is recombined with O2, you release energy, and the basic waste product is H2O (water!)  You can combust it (burn) in an engine, boil water with it, mix it with natural gas, etc.  Combustion with air oxidizes the nitrogen in that air, producing NOx emissions, and waste heat. 

A better way is to use a fuel cell, where 2 electrodes recombine the H2 and O2 to create a flow of electrons (electricity) just like a battery. The release of energy always produces waste heat, depending on the efficiency of the conversions.  Fuel cells can vary in size, and are around 80% efficient in converting the energy in the H2 into electricity with current technology.

A lot of new research is going into splitting water.  Today’s electrolyzers are around 50-60% efficient.  Many directions are being explored to split water, the simplest is exciting new research into using the sun’s energy to directly split water.  If a zucchini plant can do it, hopefully, we can eventually figure out how to do it too.

When we talk about efficiencies, we need to keep a wide perspective.  An automobile engine is about 20% efficient, meaning that 80% of the energy in the fuel is wasted as heat…hence the radiator, etc.  A typical steam power plant (coal, gas, nuclear) is about 33% efficient, with cooling towers needed to remove the 66% waste heat.  A photovoltaic cell (or module) is about 22% efficient, but the value here is the fuel is free, and the waste heat is natural and is released back into the environment. Other fuels produce excess heat being dumped into our air and waters.  A fuel cell puts out about 20% waste heat.  Our bodies put out ?? waste heat.  A FUSION reactor in the future would put out hundreds of millions of degrees into our environment!!! It is interesting how the hydrogen atom will play a key role in our energy future.

The use of hydrogen has been toyed with on the international stage for years.  Most of the work has focused on its replacing oil in the transportation sector.  Toyota, Nissan, GM, Ford, BMW have all played with hydrogen fuel vehicles, which proposes a daunting infrastructure to make it a viable option.  I think we will see hydrogen play an important role in aviation, shipping, trucking, and other vehicles that have set routes from point A where they are initially fueled to point B where they can again be refueled.  I don’t see gas stations all over the US or other countries in the world offering gasoline for the existing fleet of cars as well as hydrogen for new vehicles.  That would involve an enormous infrastructure to move the hydrogen into place.  Charging battery-powered electric vehicles is easier, and moving electrons is easier and cheaper than moving liquid or gases. 

I believe the largest role hydrogen will have in the future is to support the renewable electrification of society.  Simply put, we generate electricity from intermittent solar and wind and use any excess or what we don’t immediately need to manufacture hydrogen, which is then stored to be used in fuel cells to generate electricity when and where it is needed. 

Humboldt State proved the viability of this at the Marine Lab in Trinidad back in the early 90s.  A PV array was constructed, and 1/3rd of its output is used to power aerators in several saltwater fish tanks.  The remaining 2/3rds of the PV electricity went to an electrolyzer which split water into H2 and O2.  The hydrogen gas was compressed and stored in a tank.  At night, the hydrogen was recombined in a fuel cell (which the students themselves built) and that electricity was used to power the aerators.  The waste products are WATER and a bit of waste heat.  This system still operates today.  It is a relatively simple 30-year-old technology, but it failed to grab the attention of the energy industry until now.

Hydrogen is a BIG play now in the renewable energy world.  As the US lags, Australia, Northern Europe, China, Saudia Arabia, and a slew of other countries are investing enormous amounts of money in a multitude of research directions.  Even the nuclear industry is looking into producing Blue hydrogen (non-renewable) as opposed to Green hydrogen.  It is all very exciting, and the technologies are developing at an incredible rate.

 

Just a few examples that are being reported in the media:

 

https://reneweconomy.com.au/fortescue-buys-into-australian-low-cost-hydrogen-technology-that-only-needs-sunlight/?fbclid=IwAR1oQhPWyNQw0baBxfB7XL63ITqDsLyojzIGSN6uptOASQ_eNUc50-pJDl4

https://www.bloomberg.com/news/articles/2021-12-12/china-s-solar-giants-make-a-bid-to-dominate-hydrogen-power?utm_source=facebook&utm_campaign=socialflow-organic&cmpid=socialflow-facebook-business&utm_medium=social&utm_content=business&fbclid=IwAR2ujtWs7K2mlrEa6aLcYGsOCxkd9WkRbTpeJUOT7siBKErBph2qEvLOzN0

https://reneweconomy.com.au/forget-about-hydrogen-cars-industrial-demand-to-push-exponential-growth-in-electrolysers/?fbclid=IwAR3c6lArRfsMAP74oh7719l4YLonHxwA2ARSni8jaAhlPeun_vL_fIKiBEA

https://www.bbc.com/future/article/20190327-the-tiny-islands-leading-the-way-in-hydrogen-power

https://e360.yale.edu/features/green-hydrogen-could-it-be-key-to-a-carbon-free-economy

 

Some resources that offer information on what is happening in the renewable energy world.

Facebook group pages:                Hydrogen Fuel Cells

                                                            Hydrogen and Fuel Cell News

Plug Power (corporate news, they’ve been in the      game for many years.)

Websites:  many offer daily newsletters

            E&E news

            Elecktrek

            T&D world

            Energy tech

            Insideclimatenews

            Daily climate

A lot of information is also coming up in the more traditional media, such as Bloomberg, BBC, etc.  As with everything, it is an interesting mix of technology, politics, and money.  Let the sun shine and the wind blow!!!!!

 

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