Green Summer Holiday Homework Project: Hydrogen Gas Made Easy

Tuesday, I wrote about the possibility of using hydrogen as a fuel, and I tried to explain things in terms a motivated student in seventh or eighth might understand.  I admit, it was probably hard to follow all the way through, but if you went to the "Bottom Line" at the end of that post, I think my point was clear enough. 

Today, I'm doing a public service to all students looking for an excellent summer holiday homework science project, in case your teacher actually gives you a choice about what kind of project to do!  (If not, maybe you can use it next Earth Day.) (And if you are a teacher, then why not give your students a choice?  They'll learn more if they are investigating something they are curious about, no? Covering the syllabus is not the ultimate goal, it's just a means to an end! Educated, thoughtful students are what we really want, no?)

OK, the first thing you need to do to make an excellent project is to actually think.  Thinking may not give you higher marks, but it is, I believe, often the only difference between an excellent project from an utter and complete waste of time!  If you think, then you will be better off, regardless of your marks--regardless of whether your project works or not!  (Don't forget, science is about learning from failure as much as success!) 

The project I'm suggesting involves how people might--or might not--be able to use hydrogen as clean fuel someday.  I'm going to teach you how to actually make hydrogen gas safely. You can use this demonstration to support your argument that hydrogen is the fuel of the future--or you can use it to support your argument that hydrogen is a really great gas, but is unlikely to amount to much.  Which position you take depends on what you think!

OK, for starters, read my earlier post on hydrogen fuel.  Decide what you think, and state your position clearly: HYDROGEN: FUEL OF THE FUTURE or HYDROGEN, A HUGE WASTE OF MONEY, or even "HYDROGEN: FUTURE FUEL OR WASTE OF MONEY?  It's up to you! 

Whatever you do, take a few notes, and by all means follow the links I thoughtfully provided you. Make up your mind and make a poster that explains your thinking. (Or try a scrapbook, which my 12 year old finds easier.  It depends on the kind of presentation your teacher prefers.  Yes, pleasing your teacher will not make you smarter, but it doesn't hurt, does it?)  

As you explain your thinking, remember: a little bit of data goes a long way to support an argument. In science, especially, it's not enough to say, "I believe it, so it's true!"  But do yourself a favour, and don't use me as the source of your great data.  It's not that the Green Light Dhaba is unreliable; we are very reliable.  But, think about it--who is your teacher going to find more trustworthy--an on-line dhaba or a magazine with a name like New Scientist or Popular Mechanics?  Don't worry, follow the links provided and cite those as your sources--it won't hurt my feelings!

One more thing--use personal, local examples.  True stories from your own life can provide effective support to your argument. And personal connections should not be too hard to make regarding hydrogen.  Remember: hydrogen is a gas;  CNG is a gas...LPG is a gas!  Will our autos run on hydrogen some day?  Will we cook with it?  Cut out a photo of a cooking cylinder or a CNG powered bus or one of Delhi's green and yellow autorickshaws--you can find one every day or two in most Delhi papers.  If you don't live in Delhi, you can use the one on the right I took a few months back--don't worry, you have my permission!

Now for the real exciting bit.  Watch this video and learn how to safely make hydrogen gas.  If you work at it, you might even be able to fill a balloon with hydrogen gas, though this video does not show that.  The great thing about a hydrogen-filled balloon is that hydrogen is lighter than air, so it will float and this might get you high marks and the respect of your classmates.  However, beware!  Hydrogen will burn, which is why we don't use it in lighter than air flying machines--remember the Hindenburg?  Maybe it's better to stick with just making bubbles.

Now remember that this demonstration proves that hydrogen is not so hard to make--but it also shows that you need to use energy to get hydrogen from water!  There are, by the way, plenty of scams out there that purport to show how you can run an automobile on water and other such things. This site bursts some of those myths and is worth taking a look at. This demonstration can be used to argue several different points--and your teacher will like it because it's "hands on." Remember to bring an extra cell to school on the day you present it.  How embarrassing to run out of fuel!

By the way, if someone tells you how to make hydrogen by using sodium hydroxide, aluminum and water, please don't do it unless you have safety equipment and the help of an adult who knows what she or he is doing. This method of hydrogen production can be dangerous and your teacher may actually punish you for doing it.  Not to mention, it generates a lot of heat and involves extremely caustic chemicals and flammable gas--a bad combination all around. (Trust me on this, please, but if you don't, and need a reminder of the possible consequences, you can read this.)

Now you are ready to impress your teacher and your friends.  If you have more summer holiday homework questions, feel free to write the Green Light Dhaba any time: you can post a comment, or write us here. But I need a few days to reply; don't expect me to rescue you at the last minute!

Homework Helper: Hydrogen Fuel for 12 year olds

I'm a bit cynical about Earth Day school projects. Too often it seems like children just "go through the motions"  and turn in something because it's required. For example, this year my 12 year old son asked his his little brother what to do for his Earth Day Poster. "It's not for marks, but I have to turn something in tomorrow." 

His brother responded by saying, "Oh, that's easy, just draw a big earth, add legs, arms and a mouth, and have him say something like, 'protect the earth, we only have one!'"  Working together, they had the job done about 15 minutes. While I appreciated the brotherly love, the obvious lack of real thought tended to confirm my doubts about Earth Day projects.

A few days later, my 12 year old started asking me to explain how hydrogen might be used as a fuel in the future.  I put him off (kindly) a few times, before I realized he was really interested. When I asked him how he became curious about hydrogen fuel, he said, "Some kid made an interesting Earth Day poster about how we might be able to use algae to get hydrogen to power all kinds of things."  Wow! Maybe those posters are worth doing after all!

OK, so here's my best shot at a seventh standard explanation of the "hydrogen economy" some people like to talk about endlessly.  On Thursday, I'll explain how you can use this post to put together a really great summer holiday homework or Earth Day project. (It's up now, here!)  (If you are actually in seventh standard and find the reading is difficult, don't be discouraged!  The trick to reading hard stuff is to realize nobody understands everything they read--just keep working at it and try to get to the end, where I summarize things simply.)  For those who want more details, or want to check my sources, just follow the embedded links.

Hydrogen is the simplest element in the world--no the universe!  The sun and stars, for example, are mostly made of hydrogen.

Hydrogen is just one proton and one electron--see the diagram to the right.  Hydrogen contains a lot of energy, but it produces almost no pollution when it burns.  Liquid hydrogen is so powerful, it can be used to send rockets into space!  (The sun, by the way, does not burn hydrogen like this; the sun gets it's power from different process which we call nuclear fusion.  This is what powers hydrogen bombs. Unfortunately, we are a long way from figuring how to make nuclear fusion safe and cheap. Nuclear fusion, by the way is not the same as nuclear fission, which powers nuclear power plants and some atomic bombs. )

It's pretty easy to burn hydrogen.  When we do that, hydrogen combines with oxygen and gives us heat and water.  In addition to burning hydrogen, you can also get energy from it by using something called a fuel cell.  In a fuel cell, hydrogen combines with oxygen to produce electricity, heat, clean water, and almost no pollution.  Even now, fuel cells can produce useful electricity and power motor vehicles.  To create electricity, fuel cells require something called a catalyst, which we'll discuss below in a different context.

So hydrogen is plentiful, clean, and it can power our automobiles and our electrical appliances.  What more could we ask for?  Unfortunately, there are major problems that need to be solved before we can enter a Utopian "hydrogen economy," where we depend on clean-burning hydrogen instead of fossil fuels. We can group these problems into four categories: Production; Storage and Distribution; and Use. These problems are so major that we need to ask ourselves not just, "Is large scale use of hydrogen possible?" but also, "Is it worth it?"  These are important questions to ask whenever we consider technological "fixes." They are especially important when it comes to hydrogen fuel, because converting to a hydrogen economy would be extraordinarily expensive.  So it's not something we want to do unless the benefits are very high! 

Let's look at each group of problems in turn:

Production
If the world contained massive amounts of cheap hydrogen, we'd already have a hydrogen economy!  The problem is that hydrogen is plentiful, but in it's natural state it's almost always combined with other kinds of molecules--water, for example, is just hydrogen and oxygen!  Unfortunately, to produce usable hydrogen--to separate the hydrogen from the oxygen in water, for example--you have to use lots of energy. This means we can't really look at hydrogen as an energy source, since you have to use so much energy to get it. Hydrogen is more like a way to store energy, or an energy carrier. 

Right now, most hydrogen comes from adding heat to natural gas.  This is the cheapest way to get hydrogen.  Unfortunately, this process emits lots of  greenhouse gases, which cause global warming.  You can also get hydrogen by adding electricity to water (electrolysis), which splits the water into hydrogen and oxygen.  In addition to electricity, you need something called a catalyst.  Catalysts are materials that speed up chemical reactions. Currently, platinum is the catalyst most often used to produce hydrogen gas from water and electricity.  That's a problem, because there isn't enough platinum in the world to support a world hydrogen economy--and platinum is expensive even now.  The good news is that scientists are developing new, cheaper catalysts. 

Assuming we find a cheap enough catalyst, electrolysis would be an environmentally friendly way to produce hydrogen fuel as long as the source of electricity comes from sustainable sources, such as solar or wind power.  But we can't even generate enough sustainable electricity to run our light bulbs--we've got a lot of work to do before we'll be able to produce usable hydrogen as well!  Increasing our capacity to generate electricity sustainably makes sense, but it's going to take time.

Scientists have found that under certain conditions, algae can produce hydrogen gas.  Right now, this process is too expensive to be cost effective, but many hope this will change. Currently, scientists are developing strains of mutant algae that more efficiently use photosynthesis to break down water into oxygen and hydrogen.  Sounds a little scary, but who knows?  It just might work. 

There are other ways of producing hydrogen; these include the next generation nuclear power plants and liquefied coal. These methods have advantages and disadvantages.  (Mostly disadvantages, if you ask me, but I won't go into the details of dirty mining and nuclear power here.)  Some say we should use coal and natural gas to produce hydrogen until we can figure out more sustainable methods.  Or they say we can figure out a way to capture the carbon produced and sequester, or store, it permanently someplace. This is possible, but coal companies will never invest the money it would take to sequester carbon unless they were forced to do so--and governments don't want to do that, because high energy prices are not popular.  (For an interesting article on this, read this post and this one at Rapid Uplift.  The author is a scientist, so you can quote him!)

Unless we can figure out how to produce hydrogen sustainably, I'm not sure it really makes sense to invest billions of dollars in what it takes to store, distribute, and use hydrogen. Let's look at those problems next.

Storage and Distribution
Hydrogen is tricky stuff to store and transport.  But the problems here are not insurmountable, just expensive.  Advocates of natural gas use in the US argue that natural gas fueling stations can eventually be converted to hydrogen fueling stations.  This does seem to be a strong argument for expansion of Compressed Natural Gas (CNG) infrastructure, since CNG is cheaper and produces fewer emissions than petrol and diesel anyway.  But let's not forget that CNG powered automobiles are not sustainable in the long run, because even if they are better than petrol or diesel vehicles, they do produce greenhouse gases.  This is especially true if people use cars to to the extent that they do in the US--or New Delhi.  To its credit, Delhi has been using CNG to power buses and autorickshaws for years, and it did lead to less pollution--at least until the number of private diesel vehicles drastically increased.

Moving hydrogen from one place to another (distribution) is problematic, because it takes a lot of energy to transport it by truck or train.  That leads to inefficiencies--and higher emissions.  In the long run, pipelines are the cheapest way to transport hydrogen.  The problem is, pipelines are expensive because they need to be specially treated; currently in the US, every 10 km of pipeline costs over six million dollars to build.  That's not cheap.

One solution to the transport problem is the produce hydrogen locally--at or near the filling station.  So far, most efforts to do this have involved natural gas, which means carbon emissions.  If that's the best we can do, it might make sense to drive less and use natural gas directly!

Use
As noted above, there are many ways we can use hydrogen.  Fuel cell vehicles, power generation, and rocket ship travel are three! Right now, hydrogen powered cars are very expensive, but those costs will come down with improved technology.  Large scale electricity generation from hydrogen probably doesn't make much sense unless we can figure out how to use algae to produce hydrogen cheaply.  That may or may not happen.  As for rocket ship travel, I wouldn't count on that becoming sustainable in our life time!

For a good overview of the costs associated with the different parts of the "hydrogen economy," take a look at this article in Popular Mechanics.

Bottom Line:
If we can come up with a cheap, sustainable way to produce hydrogen, it could solve a lot of our current energy problems.  I support basic research for this reason.  Failing that, it probably makes more sense to keep things simple: use solar and wind power to run light bulbs and to heat water; encourage bicycle use; replace automobiles with trains and natural gas buses; that kind of thing. The good news is that at least some of the infrastructure we use to store and distribute natural gas could eventually be converted for hydrogen use.  So if we develop a cheap, sustainable source of hydrogen, the investment we put into fleets of natural gas powered buses won't be a complete waste.  Given that, a go-slow approach doesn't close any doors.

What doesn't make sense is to invent a massively expensive infrastructure to make our unsustainable use of automobiles slightly less unsustainable.  My advice to seventh standard students?  Don't count on hydrogen to solve your future problems, but if you're passionate about science, this is one area where bright minds are required!