Fossils Today, Hydrogen Tomorrow

Our Future With a Hydrogen Economy

By: Mike Nikolov and Charlie Giger

Definition

A hydrogen economy is a hypothetical economy in which the energy needed for motive power (for automobiles and other vehicle types) or electricity (for stationary applications) is derived from reacting hydrogen with oxygen. While the primary purpose is to eliminate the use of carbon-based fossil fuels and thus reduce carbon dioxide emissions, a secondary goal is to provide an energy carrier to replace dwindling supplies of petroleum as well as to provide energy independence to countries without oil resources.

1. Global Warming2. Fossil Fuel depletion3. Dependence on fossil fuels4. Environmental Pollution5. Gas Prices! ! !

Why A Hydrogen Economy?

Benefits

Hydrogen is an environmentally cleaner source of energy to end-users, particularly in transportation applications. This is because it does not release pollutants or greenhouse gases at the point of end use. Studies have concluded that most of the hydrogen supply chain pathways would release significantly less carbon dioxide into the atmosphere than would gasoline used even in hybrid electric vehicles.

Methods of Production

Biological Production Electrolysis High-Temperature Electrolysis (HTE) Thermo-Chemical Production Reactive Production

Biological Production

Bio-hydrogen can be produced in an algae bioreactor. An experiment in the 1990s found that when algae is deprived from sulfur, the production of hydrogen occurs instead of oxygen.

In bioreactors, biohydrogen can be created by utilizing raw material, such as waste streams. The routine consists of bacteria feeding on hydrocarbons and exhaling hydrogen and CO2. The CO2 can be secluded successfully by many methods, resulting in hydrogen gas.

Bioreactor Process

Electrolysis

The main methods of hydrogen production depend on exothermic chemical reactions of fossil fuels to furnish the energy needed to chemically transform raw material into hydrogen. But when the energy supply is mechanical (hydropower or wind turbines), hydrogen can be produced by way of electrolysis of water or a process that brings about a chemical reaction by passing electric current through a material (in this case H20).

High-Temperature Electrolysis (HTE) Hydrogen can be rendered from energy provided in the

form of heat (e.g., that of concentrating solar thermal or nuclear) and electricity through high-temperature electrolysis (HTE).

HTE of water transform more of the first heat energy into chemical energy (hydrogen), having a chance of doubling efficiency, to about 50%. Some of the energy in HTE is provided in the form of heat, and less of the energy must be converted twice (from heat to electricity, and then to chemical form), and so potentially much less energy is required per kilogram of hydrogen made. HTE has been shown in a laboratory, but not commercially.

Thermo-Chemical Production Thermo-chemical processes are able to make

hydrogen and oxygen from water and heat without using electricity. These experiments tend to be more efficient than high-temperature electrolysis. Thermo -chemical energy such as gas or coal is not considered, because the chemical path is more efficient.

Thermo-chemical hydrogen production are not yet able to be made at production levels, although the chemical has been made in laboratories.

Reactive Production

Hydrogen is an element that combines with many different metals. Sodium, with water and sodium metal reacting, make sodium hydroxide and hydrogen. A recent interest as been the element, aluminum (as an aluminum/gallium alloy) reacting with water to make aluminum oxide and hydrogen. Metal is used entirely throughout the process.

•Storage

•The mass of the tanks needed for compressed hydrogen reduces the fuel economy of the vehicle.

•Distinct from storing molecular hydrogen, hydrogen can be stored as a chemical hydride or in some other hydrogen-containing compound.

•Hydrogen gas is reacted with some other materials to produce the hydrogen storage material, which can be transported relatively easily. At the point of use the hydrogen storage material can be made to decompose, yielding hydrogen gas.

• As well as the mass and volume density problems associated with molecular hydrogen storage, current barriers to practical storage schemes stem from the high pressure and temperature conditions needed for hydride formation and hydrogen release.

Supply & Demand Chart

QuickTime™ and a decompressor

are needed to see this picture.

Efficiency as an Automotive Fuel

An explanation of the energy utilized during a thermodynamic process, is mostly applied to automotive fuels. With today's technology, the manufacture of hydrogen by way of steam conversion can be accomplished with a thermal efficiency of 75 to 80 percent. Additional energy will be made to compress the hydrogen, and to transport it to the filling station by way of truck or pipeline.

Steps Toward a Cleaner Future

What All Cars and Gas Stations Should Be Like