Alcohol vs. H2

Fueling for the future


The argument for a practical solution to the cost of use of foreign oil for vehicles.

A system engineerís viewpoint.  March, 2005


The Administrationís proposed hydrogen initiative for energy savings.

Hydrogen fuel cells to replace the gasoline internal combustion engine have been announced as the federal initiative to decrease oil dependency.  And the American people have calmly accepted the Bush administration announcement, as if government money can accomplish anything.  But should it? We are advised that large amounts of money are being poured into the major research companies to accomplish this pie-in-the-sky goal. 


Do the numbers

2004 sales of cars and light trucks reached  almost 10 million units in the first six months.  Similar numbers were sold in the corresponding months of 2003.  This may be extended to mean that about 100 million vehicles less than 5 years old are serving as light transport in the USA. Assume about 15,000 miles annually per vehicle on the average, and we may reasonably assume that the average mileage is about 15 miles per gallon.  1,000 gallons of gasoline per vehicle, then, is required annually for those newer vehicles on the road, for a total of about 100,000,000,000 gallons of gasoline to run the nationís fleet of incidental transport. (The digits are deliberate, to avoid the eyes-glazing-over effect.). To replace this would require about 200 billion gallons of hydrogen in addition to the 100 million fuel cells, and the electricity generation capacity to produce the hydrogen.  Annually.  And that doesnít address the 18 wheelers, which run on diesel that could be more efficently used on upgraded railroads for long haul freight.


Hydrogen must be separated, probably by electrolysis

Electrolysis is accomplished with massive amounts of electrical energy.  By-products of producing this electrical power are CO2, nitrogen oxides, and particulate matter from coal or natural gas. The volume of hydrogen that would have to be generated to satisfy this need boggles the mind.  From searching the web sites, it appears that the most feasible plan is to deploy a generator unit to each consumer.  Such units would run on electricity and be dependent on the consumer to operate them safely.  Not very practical.


Hydrogen must be stored and transported

Currently, hydrogen is transported in high pressure tanks.  Research is underway to come up with means of storing it.  Under high pressure, it seeks to escape.  A punctured tank is a major explosion hazard.  Hydrogen is a very small molecule, escapes easily, so has high transmission losses.  Pipelines will have to be built all over the country; or the current fuel truck fleet will have to be duplicated with high pressure tank trucks. The carnage when a wreck occurs can only be imagined.  Gas serving stations would be much more complex, all must be replaced and people must be trained to use the high pressure connections needed to service vehicles.  Accidents with large volumes of flame can be expected if current methods of handling the fuel are employed.  Hydrogen explosions are not only likely where the gas is being generated, they are very brisant.  Judging by the current political barriers to permits for new natural gas facilities, hydrogen handling permits will be very scarce and expensive.  This is incompatible with the idea of each user owning and operating his/her own small H2 production facility as suggested by some proponents of the hydrogen economy. 


Personal vehicles must be designed, built and deployed.

Hydrogen has small energy density, which translates to short range for vehicles that use it for prime fuel.  See above for the result of a rear end collision.  In order to make the effort pay off, all gasoline burning vehicles must be moved off the road.  Thus, all privately owned vehicles would have to be junked, creating a huge steel surplus and requiring replacement.  Buying new is beyond many people, so that government incentives would have to be offered.  A minimum of ten years would be required to get half of those vehicles off the road.



What is a practical alternative?

Let us consider an alternative that would accomplish in near term the desired relief from foreign oil.  Methanol, or more familiarly, alcohol, can be stored in the same underground tanks and pumped by the same service pumps we currently use for gasoline.  The methanol can also use the same pipelines that currently transfer gasoline all over the country.  Methanol has been used for many years as an additive to gasoline in internal combustion engines.  Our current engines donít burn 100% alcohol very well, and alcohol has a lower energy density than gasoline, but  a larger tank would take care of that if we could design an engine that would be acceptable to the average consumer and could burn 100% alcohol.  Suddenly, farmers all over the country would have a market for their crops Ė specifically, corn, which can be converted effectively into methanol.  The waste is cellulose, which can be converted to charcoal or fertilizer.  In fact, there has been some success in converting cellulose into beer, which can be distilled into yet more alcohol.  With all that alcohol, of course, we would have to add some gasoline to eliminate the problems that internal consumption would cause.  Now, what kind of engine do we need to extract the energy from alcohol?



Light weight turbine engine driving a generator

Chrysler Corporation had a program for several years up to 1979 that intended to use turbine engines to power cars.  A turbine can burn almost anything that  will burn, and at its design speed, burn it very efficiently.  It has to have a controlled mix of air and fuel, which modern computers can do very well.  The turbine does have a problem with rapid acceleration, but it packs a great deal of torque into a small package.  If we drive an electrical generator with a turbine, and store the energy from that generator in a battery at about 300 volts, we would have a power source for electrical motors, which have no acceleration lag, and which can be used to provide regenerative braking.  This smoothes the peak horsepower requirement for the turbine and allows it to run at constant speed when it is generating power.  Another source of energy savings!  Suppose we build an electrical motor into the hub of each of the four wheels, along with the appropriate wiring and some braking power.


Electrical motors drive wheels, and regenerative braking

Now, suddenly we have a platform with four-wheel independent drive.  The motor weight is off-loaded from the suspended platform.  The turbine only loads up when the battery indicates it needs to take on more energy.  The rest of the time, it is idling at no load, being spun with a very small percentage of the power from the battery.  A characteristic of an electrical drive system such as this is that it is full time four wheel drive.  If one wheel slips, less power goes to that wheel, and the weight of the vehicle presses on the other wheels, giving the vehicle more traction.  Interestingly enough, the entire package can be built into a box about eight to sixteen inches high that rests between the wheel.  The body, passenger comfort components, and suspension would then be added for the desired functionality.  This lowers the center of mass, improving the rollover characteristics of the vehicle. General Motors has shown concept cars with this as the design basis for several years.  All of the components that I have described here are written up in the September  2004 issue of Popular Science.  One one-hundredth of the money being spent on the hydrogen initiative could have the vehicle built and tested within two years.


Advantages of the hybrid drive platform

This full size vehicle requires no transmission, no differential, has four wheel full time drive, and emits no pollution at rest.  It is quiet, has sufficient power for road driving, high fuel efficiency for plenty of range, and gives farmers a market for their crops while relieving the US of its dependence on foreign oil and opening a market to export these vehicles to the rest of the world.  And by the way, video of a vehicle very similar to what I have described was shown on the history channel some weeks ago.  It was being tested for off-road use by the U S Army, a vehicle very similar in concept to the Bradley Fighting Vehicle.  A major benefit of using methanol to drive our millions of vehicles would be a tremendous decrease in the nitrogen oxides emitted by the vehicular transport; the use of turbines operating at their optimum range would decrease the amount of carbon dioxide and particulates spurted into the air, alleviating the exhaust of greenhouse gas and its consequent atmospheric warming.


Effect of a practical energy alternative on foreign policy

We have to wonder whether the goal of the hydrogen initiative is really to relieve the US of its energy dependence on foreign oil. Since it is so impractical, we have to wonder what is to be accomplished.  Up to now, foreign policy options have been so limited as to drive us to an ill-advised war.  If the US were independent of that foreign oil, its current credibility crisis would be much relieved, and it might even be expected that more potential friends around the world would be interested in purchasing those US made vehicles.  


The petroleum crisis in Japan and China could largely be averted if their farms were to be used to produce straw as well as food and the straw converted to alcohol for fuel to replace gasoline.