Hydrogen vs. Biodiesel fuel

Two of our own have engaged in a friendly (we hope) debate over the desirability of hydrogen fuel versus diesel fuel from biological sources as a replacement for petroleum-based fuels.

One of Tami Freedman's comments on the subject:

“Hydrogen Economy” a Boondoggle

While the "hydrogen economy" receives much media attention, there are serious problems with hydrogen as transportation fuel. The first is hydrogen gas is extremely explosive. Hydrogen must be pressurized to 250 atmospheres for use as fuel, requiring corrosion-resistant tanks that don't rust, spring leaks, and explode. Hydrogen’s low energy density requires fuel tanks 14 times as large to yield the same driving range. To get a 1,000 mile range, a tractor trailer needs 168 gallons of diesel. Hydrogen vehicles would require 2,360 gallons of hydrogen, stored at 250 atmospheres. Dedicating that much space to fuel storage would drastically reduce how much trucks could carry, while the costs of high-pressure, corrosion-resistant storage tanks -- astronomical. The two main options for producing hydrogen, generating from water and extracting from other fuels, both have energy efficiencies below 100%, (takes more energy to produce than you get). Hydrogen vehicles (currently $1 million each to produce) would need a widescale hydrogen fuel distribution system. With a single hydrogen fuel pump costing $1 million, installing six at each of the 176,000 fuel stations across the US is over $1 trillion - costs completely avoided with biofuels that use our current infrastructure.

. . . followed by a response from Wade Swicord:

Hey Tami,

Good pass through. There has been a lot of discussion concerning the viability of hydrogen and a lot is rightfully centered on the storage problem. I do not feel that this is the end all of the energy question but it certainly deserves to survive the bath water. There is now a hydrogen powered cell phone and this being the micro reality, you can be assured that soon the behemoth storage systems as described in the forwarded article will be shedding pounds and inches. What I like is the introduction of more organic type elements in the storage systems which somewhat validates my push to move into the molecular application of hemp, which is a prime replacement material for petrochemical polymers. Do please read the following article and see how this could perhaps modify the stand taken in your forwarded comment.

Keep up the eagle eye,

Wade

PolyFuel’s membranes have garnered much interest in the portable electronics industry as they continue to raise the bar on fuel cell performance, in spite of the tremendous technical challenges in nano-engineering the exotic plastic films. Such increased performance is causing PolyFuel’s hydrocarbon membranes to displace alternative technologies, particularly fluorocarbon membranes, in much of the new and existing portable fuel cell development around the world.

State of the Art

There are essentially two alternative technologies for the design of portable direct methanol fuel cells (DMFCs), based upon the type of polymer used to create the plastic film-like membranes that make fuel cells possible. One technology, pioneered by DuPont�, uses membranes based on fluorocarbon polymers, similar to the ones used to manufacture the non-stick Teflon� coating on frying pans, and fibers for Gore-Tex� water-resistant fabrics. DuPont originally developed the so-called fluorocarbon membranes, now marketed under the trade name Nafion�, in the late 1960s, for the early U.S. space program.

The other technology, significantly newer in origin, has been pioneered by PolyFuel, SRI, Honda, and others. Instead of fluorocarbon polymers, the technology uses hydrocarbon polymers – long chains of organic molecules of varying composition – to form extremely stable films with carefully engineered properties.

Literally decades of research, and by some estimates hundreds of millions of dollars, have been expended on these exotic membranes – tens of millions by PolyFuel alone. Although there continues to be active development work on fluorocarbon-based fuel cells, in recent years, the most active and promising developments have come from hydrocarbon membranes, many of them from PolyFuel, because of the widening performance gap between the two fundamental technologies. Samsung, for example, recently characterized PolyFuel’s latest membrane as “a breakthrough” in their efforts to develop portable fuel cells (see: “PolyFuel Sets New Record for Portable Fuel Cell Performance – Again”, November 7, 2006). Much of the technology behind that breakthrough membrane is protected by these two new patents.

How it All Works – A Layman’s View

Fuel cells can be thought of as refillable batteries. Unlike batteries, which when exhausted must be discarded or recharged over a number of hours, fuel cells will keep producing power indefinitely, as long as there is fuel. In fuel cells being designed for portable consumer electronics devices, snap-in cartridges – the size of disposable cigarette lighters in several handheld designs – can be carried in pocket or purse, and popped into the fuel cell as required. One such cartridge, containing just a few ounces of methanol (CH3OH) and water (H2O), might power a laptop computer for 8 hours or more.

A portable, “direct methanol” fuel cell (DMFC) works by extracting energy directly from just such a mixture of methanol and water. The energy is extracted electrochemically, in the form of electricity, without combustion.

The heart of the fuel cell is the fuel cell membrane, and it is the membrane that determines many of the key properties of the fuel cell, such as size, weight, cost and runtime. The membrane is coated with a thin layer of catalyst, typically platinum, which helps increase the rate at which the electricity is produced.

At the interface between the catalyst and the membrane on the fuel side of the fuel cell, the hydrogen atoms in the methanol and water molecules spontaneously split into negatively charged electrons and positively charged protons – which are simply hydrogen atoms missing their usual, single electron. The protons pass through small channels in the membrane from the fuel side of the fuel cell to the air side. The electrons, by contrast, travel outside the fuel cell as electricity and do useful work such as powering a laptop. On the air side of the fuel cell, returning electrons recombine with protons that have crossed through the membrane, and with oxygen present in the air, to complete the reaction, creating water vapor as a by-product.

For many years, and prior to the widespread availability of hydrocarbon membranes from PolyFuel, developers of DMFC fuel cells had no choice but to use fluorocarbon membrane materials, which were originally developed for hydrogen fuel cells. However, fluorocarbon membranes have some significant performance drawbacks when used in direct methanol fuel cells. First their proton-conducting channels tend to be somewhat larger than is optimal. Second, fluorocarbon membranes have a soft, rubbery consistency, and in the presence of methanol, they tend to swell, making the proton channels even larger still.

The net effect of these drawbacks is that the water and methanol from the fuel supply practically pour through the channels, along with the protons, however without making any electricity. This significantly reduces the efficiency of a fluorocarbon membrane-based fuel cell and requires that the fuel cell have a larger fuel tank. Additionally, when the unwanted water and methanol arrive at the air side of the fuel cell, they essentially “drown” the catalyst, by preventing ambient oxygen from reaching the protons and electrons to complete the fuel cell reaction. To make matters worse, the uninvited methanol itself reacts with the air and creates heat, even more water, and carbon dioxide (CO2) – reducing the efficiency of the fuel cell even further.

PolyFuel’s now-patented hydrocarbon membrane material self-assembles proton channels that are nano-engineered to be significantly smaller than those in fluorocarbon membranes. The polymer matrix is also much tougher and stronger so that it does not swell to the same degree as fluorocarbon membranes do. The net result is that more of the water and methanol remain on the fuel side of the fuel cell, where they can be used to create useful electricity. The fuel cell is also able to breathe easier, and doesn’t create as much heat, water and CO2. This in turn enables the fuel cell to be smaller, lighter, less expensive, and longer running.

These characteristics of the PolyFuel-based fuel cell are critically important to portable fuel cell system developers, and environmentally conscious consumers.

PolyFuel’s composition of matter patents, US 7,094,490, and 7,202,001 describe the chemistry behind these concepts. Together the patents are broad in their scope, and describe a nearly infinite number of permutations of hydrocarbon membranes, which gives the company outstanding protection in such an important, commercially imminent field.

Wade has since added this analysis:

Tami,



Our group is established to work with what we have locally and what anyone can bring to the table as a project that can perhaps have viability. How we do this and how we pay for it is yet to be fully worked out. There are many proposals that have been shorted in recognition and funding. What we want to do is bring these projects to the front and have them worked on or recognized. It is useless to complain about what is being funded. Our intent is to find viable projects and work to bring them to productivity. It would really be a fine thing if some one would present to our group a viable proposal for the development of the algae-energy process. Unfortunately, at the early stages of our growth, we really need to show salability or early potential profit. Once under way we can support exploratory developments that seem to be rather odd.



You are a real spark in the energy world and we need more folk like you. Keep it up.



Wade

Followed by Tami's response:

Hi Wade,



I don't have a holy grail, I accept kudzu and methane, etc. However to not put

any govt research money into algae (15,000 gal / acre) and put $1 billion govt $ into

hydrogen - explosive, need all new tanks/distribution system, etc. - HORRIFIED.



Blessings, T

To which Wade has replied as follows:

ey Tami,



It is true that hydrogen has its problems and one may think, perhaps a bit of a diversion. I think I said or thought I did, that I am not a fan of hydrogen. Right now I am not a fan of anything unless one can bring the project in doable form to our review committee. It looks like to me that there is a lot of research going on with algae. This is in respect to some of the other lesser proposed energy modes. Life has no one way to live and there is likely no absolute holy grail for energy. If it exist, the energy solution, it will come as a gift, free of production complications, and likely take some time to be accepted.



Keep rattleling the group… just love it.



Wade