New process is promising for hydrogen fuel cell cars

Jun 16, 2010 by Emil Venere
From left, Arvind Varma, Purdue University's R. Games Slayter Distinguished Professor of Chemical Engineering, postdoctoral researcher Hyun Tae Hwang and doctoral student Ahmad Al-Kukhun review data from a new process for storing and generating hydrogen to run fuel cells in cars and portable consumer electronics. The process, called hydrothermolysis, uses a powdered material called ammonia borane, which contains one of the highest hydrogen contents of all solid materials. Credit: Purdue University photo/Andrew Hancock

A new process for storing and generating hydrogen to run fuel cells in cars has been invented by chemical engineers at Purdue University.

The process, given the name hydrothermolysis, uses a powdered chemical called ammonia borane, which has one of the highest hydrogen contents of all solid materials, said Arvind Varma, R. Games Slayter Distinguished Professor of Chemical Engineering and head of the School of Chemical Engineering.

"This is the first process to provide exceptionally high hydrogen yield values at near the operating temperatures without using a catalyst, making it promising for hydrogen-powered vehicles," he said. "We have a proof of concept."

The new process combines hydrolysis and thermolysis, two hydrogen-generating processes that are not practical by themselves for vehicle applications.

Research findings were presented June 15 during the International Symposium on Chemical Reaction Engineering in Philadelphia. The research also is detailed in a paper appearing online in the AIChE Journal, published by the American Institute of Chemical Engineers, and will be published in an upcoming issue of the journal.

Ammonia borane contains 19.6 percent hydrogen, a high weight percentage that means a relatively small quantity and volume of the material are needed to store large amounts of hydrogen, Varma said.

"The key is how to efficiently release the hydrogen from this compound, and that is what we have discovered," he said.

The paper was written by former Purdue doctoral student Moiz Diwan, now a senior research engineer at Abbott Laboratories in Chicago; Purdue postdoctoral researcher Hyun Tae Hwang; doctoral student Ahmad Al-Kukhun; and Varma. Purdue has filed a on the technology.

In hydrolysis, water is combined with ammonia borane and the process requires a catalyst to generate hydrogen, while in thermolysis the material must be heated to more than 170 degrees Celsius, or more than 330 degrees Fahrenheit, to release sufficient quantities of hydrogen.

However, fuel cells that will be used in cars operate at about 85 degrees Celsius (185 degrees Fahrenheit). Hydrogen fuel cells generate electricity to run an electric motor.

The new process also promises to harness waste heat from fuel cells to operate the hydrogen generation reactor, Varma said.

The researchers conducted experiments using a reactor vessel operating at the same temperature as fuel cells. The process requires maintaining the reactor at a pressure of less than 200 pounds per square inch, far lower than the 5,000 psi required for current hydrogen-powered test vehicles that use compressed hydrogen gas stored in tanks.

In some experiments, the researchers used water containing a form of hydrogen called deuterium. Using water containing deuterium instead of hydrogen enabled the researchers to trace how much hydrogen is generated from the hydrolysis reaction and how much from the thermolysis reaction, details critical to understanding the process.

At the optimum conditions, hydrogen from the hydrothermolysis approach amounted to about 14 percent of the total weight of the ammonia borane and water used in the process. This is significantly higher than the hydrogen yields from other experimental systems reported in the scientific literature, Varma said.

"This is important because the U.S. Department of Energy has set a 2015 target of 5.5 weight percent hydrogen for hydrogen storage systems, meaning available hydrogen should be at least 5.5 percent of a system's total weight," he said. "If you're only yielding, say, 7 percent hydrogen from the material, you're not going to make this 5.5 percent requirement once you consider the combined weight of the entire system, which includes the reactor, tubing, the ammonia borane, water, valves and other required equipment."

The researchers determined that a concentration of 77 percent ammonia borane is ideal for maximum hydrogen yield using the new process.

The research has been funded by the U.S. Department of Energy by a grant through the Energy Center in Purdue's Discovery Park.

Future work on hydrothermolysis will explore scaling up the reactor to the size required for a vehicle to drive 350 miles before refueling. Additional research also is needed to develop recycling technologies for turning waste residues produced in the process back into .

The technology may also be used to produce for fuel cells to recharge batteries in portable electronics, such as notebook computers, cell phones, personal digital assistants, digital cameras, handheld medical diagnostic devices and defibrillators.

"The recycling isn't important for small-scale applications, such as portable electronics, but is needed before the process becomes practical for cars," Varma said.

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lengould100
2.3 / 5 (3) Jun 16, 2010
Ok, now what's the energy input amounts and characteristics for generating of ammonia borane?
StandingBear
1 / 5 (2) Jun 16, 2010
Hey I like this one. These guys are smart. Boron is common in the earth. Adoption on a massive scale once a practical design is formulated will allow us to protect our remaining oil supply for use as lubricants, as it should be.
antialias_physorg
3.5 / 5 (2) Jun 16, 2010
The additional advantage is that you could go to a gas station, dump the used ammonia borane to be recycled and fill up with a charged load.

No long recharging times like E-vehicles and no self discharge, either. Good stuff.
JimB135
4 / 5 (2) Jun 16, 2010
protect our remaining oil supply for use as lubricants, as it should be.


Much more than lubricants. Petrochemicals are the entire basis for modern civilization. From the energy provided to run everything to the raw materials needed to provide us with a mind boggling number of products. From the road you drive on, to the medications you need to the cell phone you talk on -- petrochemicals are there every step of the way.
Shootist
1 / 5 (3) Jun 16, 2010
Hey I like this one. These guys are smart. Boron is common in the earth. Adoption on a massive scale once a practical design is formulated will allow us to protect our remaining oil supply for use as lubricants, as it should be.


Yeah, right. And the ammonia comes from?

Petroleum.
Tan0r5
1 / 5 (2) Jun 17, 2010
Water is necessary for life. How many will die of thirst without clean water which was converted into hydrogen? How many will die of hunger because corn is converted into ethanol? Convert all wastes into fuel without petroleum, chemicals, or burning using a heat compression process.
antialias
not rated yet Jun 17, 2010
Yeah, right. And the ammonia comes from?

Petroleum.

But in this case it is a reusable/rechargeable energy carrier - and not a primary energy source which gets used up.
Bog_Mire
1 / 5 (1) Jun 17, 2010
Hey I like this one. These guys are smart. Boron is common in the earth. Adoption on a massive scale once a practical design is formulated will allow us to protect our remaining oil supply for use as lubricants, as it should be.


Yeah, right. And the ammonia comes from?

Petroleum.


chook poo?
Shootist
1 / 5 (2) Jun 17, 2010
Water is necessary for life. How many will die of thirst without clean water which was converted into hydrogen? How many will die of hunger because corn is converted into ethanol? Convert all wastes into fuel without petroleum, chemicals, or burning using a heat compression process.


I dunno, jeez just flash sea water if you're worried about it. Several dozen 1000MW Nuke plants will go a long way.
Shootist
1 / 5 (2) Jun 17, 2010
Yeah, right. And the ammonia comes from?

Petroleum.


But in this case it is a reusable/rechargeable energy carrier - and not a primary energy source which gets used up.


No it isn't reuseable. The ammonia is broken down for its H2. Poof no more ammonia.

To make this fairie dust work, YOU HAVE TO:

Use petroleum to find more petroleum.
Use petroleum to pump more petroleum.
Use petroleum to refine more petroleum.
Use petroleum to make more ammonia.
Use petroleum to power all these refining/refractory processes.
Use petroleum to transport the ammonia.
Use petroleum to mine the borax.
Use petroleum to refine the Borax.
Use petroleum to transport the borax.

And, finally,

use petroleum to combine the borax and ammonia,
use petroleum to transport the ammonia-boron compound, to fuel the fuel cell powered vehicles which were transported from the point of manufacture to the point of sale via petroleum powered vehicles.
Shootist
1 / 5 (2) Jun 17, 2010
We have to stop getting excited about energy negative energy sources. More energy goes into the creation of this ammonia-boron mess than will ever be extracted.

There are no Hydrogen mines.

Unless, or until, sufficient nuclear generating capacity is built to cheaply (nearly free) extract H2 from seawater, H2 will, like ethanol/methanol, remain the fuel of fools.
CyberRat
not rated yet Jun 17, 2010
Correction

--------------
Yeah, right. And the ammonia comes from?
To make this fairie dust work, YOU HAVE TO:
Use nuclear/solar/wind/etc to produce hydrogen
Use hydrogen to find more petroleum.
Use hydrogen to pump more petroleum.
Use hydrogen to refine more petroleum.
Use hydrogen/petroleum to make more ammonia.
Use solar/nuclear to power all these refining/refractory processes.
Use hydrogen to transport the ammonia.
Use hydrogen to mine the borax.
Use hydrogen to refine the Borax.
Use hydrogen to transport the borax.
use hydrogen to combine the borax and ammonia,
use hydrogen to transport the ammonia-boron compound, to fuel the fuel cell powered vehicles which were transported from the point of manufacture to the point of sale via hydrogen powered vehicles.

antialias_physorg
not rated yet Jun 17, 2010
We have to stop getting excited about energy negative energy sources. More energy goes into the creation of this ammonia-boron mess than will ever be extracted.


Umm...ALL energy sources are energy negative. Ammonia borane is not an energy source but energy STORAGE. It's liek a battery (with a alot of advantages). Even with a battery you have to put more energy in than you get out.

The point is that lot of alternative enery sources require an energy storage solution (wind, solar) because they need to store excess production and/or keep delivering energy to the grid when the sund doesn't shine or the wind doesn't blow.

For alternative automotive solutions we require an energy storage medium that that can be stored indefinitely and doesn't take long to recharge (or can simply be exchanged like liquid fuel). This stuff could do that.
Ozz
not rated yet Jun 18, 2010
When I was in Organic Chemistry we were told that basicly all of our pharmaceuticals come from oil. As a matter of fact, early organic chemistry students were handed a tar ball and instructed to extract different hydrocarbons. The pharm industry has grown up with the the oil industry. We do need to save the oil for important medicines.
Hydrogen is the transportation energy gold standard.
Ozz
not rated yet Jun 18, 2010
We won't use up the water by using hydrogen for transportation. In making electricity using hydrogen water is made. Water and oxygen are the reaction waste products in supplying the electons from hydrogen. Ammonia is already big in the energy world and many are calling it "The Other Hydrogen." Check out Iowa University or Iowa State I can't remember which, but they have a great plan using ammonia and several other energy sources.
Forestgnome
1 / 5 (1) Jun 19, 2010
Hey I like this one. These guys are smart. Boron is common in the earth. Adoption on a massive scale once a practical design is formulated will allow us to protect our remaining oil supply for use as lubricants, as it should be.


Yeah, right. And the ammonia comes from?

Petroleum.


No, actually from coal. But that's okay, as most of it comes from China. They'll get the pollution, we'll get to clean up and feel good about ourselves!
Ozz
not rated yet Jun 19, 2010
Ammonia is made using many different energy sources including coal, but it is not burned ammonia NH3 is being produced in very large volumes in this country and can be used a as fuel itself. Check out the Iowa Energy Center and see the intergrated system they have designed. I'm sure google will do.
ShotmanMaslo
1 / 5 (1) Jun 20, 2010
The additional advantage is that you could go to a gas station, dump the used ammonia borane to be recycled and fill up with a charged load.

No long recharging times like E-vehicles and no self discharge, either. Good stuff.


Batteries in EVs could be made swappable, so long recharging times are not a show-stoper.
Sanescience
not rated yet Jun 21, 2010
STOP THE MADNESS

Hydrogen systems are generally a bad idea. Inefficient, expensive, and will put car maintenance out of the hands of ordinary mechanics and owners.

We need to re-use our current infrastructure for storage and transportation of energy and not pay big corporations trillions of dollars to build a new one.

We need Bio Diesel that is carbon neutral, from processes and crops that do not compete with food. And is fully sustainable without the need for major mining operations and can be decentralized to reduce transportation waste.

Three sources for bio-diesel could satisfy much of the demand:
1) Conversion of cellulose from crop waste or grown on marginal land (like switch grass)
2) Hydroponic algae farms in the desserts.
3) Direct energy conversion from solar and wind into fuel via microbial electrosynthesis.
antialias
not rated yet Jun 21, 2010
Batteries in EVs could be made swappable, so long recharging times are not a show-stoper.
This would require universal standardization of batteries. With the ongoing development of new and better battery types that's unlikely to happen (and if it did it would be counter-productive).

and will put car maintenance out of the hands of ordinary mechanics and owners

As if anyone could repair a modern car in their own garage. Battery/electrical faults account for 40% of all car failures already.

1) Conversion of cellulose from crop waste or grown on marginal land (like switch grass)
2) Hydroponic algae farms in the desserts.
3) Direct energy conversion from solar and wind into fuel via microbial electrosynthesis.

Wow - you're calling hydrogen conversion inefficient (currently at 12.4% direct solar to hydrogen) but are advocating photosythesis derived biomass (which is only 3% efficient)? Astonishing.