Hydrogen gas is one of the most abundant elements on the planet. This makes it possible to produce the element in gas form using a wide variety of methods and raw materials providing possibly the most flexible fuel on the earth. In a traditional plant setting, producing hydrogen gas can begin with raw materials such as coal, water, natural gas, algae or biomass (natural organic composting materials).
Producing hydrogen gas from raw materials such as coal or biomass is called gasification, which requires heating the raw materials at a variety of extremely high temperatures, followed by a cooling, separation and purification process. The resulting hydrogen gas can then be used for any traditional fuel needs, or used as fuel to generate electricity. Coal gasification, when used to produce hydrogen gas as a fuel for generating electricity, produces much lower emissions than the traditional coal fueled power plant.
The least polluting and environmentally clean way to produce hydrogen gas involves extracting it from water. Several different methods are used to accomplish this, but electrolysis is the best method. Electrolysis produces hydrogen gas from water by using electric current to separate out the hydrogen from oxygen. The by-products of such a process are hydrogen and oxygen gas. The electricity used to power the method can be derived from renewable energy sources, such as solar or wind generators. Geothermal or hydro power can also provide the initial energy source. Nuclear-generated power may also be used for the electrolysis method.
The Thermochemical Water Splitting method of producing hydrogen gas separates hydrogen from water using a chemical reaction between water and certain chemicals at high temperatures. This is primary accomplished at nuclear plants. High-temperature Electrolysis is the same basic concept as fueled by electricity except this method uses the heat generated by nuclear power production to bring the water to the correct temperature instead of electrical current.
Producing hydrogen gas using natural gas as the raw material is achieved through a process called Steam Methane Reformation. This is a two-step method, which burns the natural gas to create steam, which results in a synthesis gas from which the hydrogen can be separated. This method, though not as environmentally friendly as electrolysis is currently used to produce roughly ninety-five percent of all hydrogen in the United States.
Hydrogen can also be produced from algae or bacteria found in wastewater using a method called Photo-Biological Production. Using this method the algae are deprived of sulfur, which causes them to stop emitting oxygen and emit hydrogen. This method of producing hydrogen gas is currently receiving a great deal of attention because it is the greenest of all the methods utilizing both renewable and waste material by products as its primary ingredient or “feedstock”.
There are already many applications for hydrogen gas but given the great abundance of the element it seems that research into applications that use the gas will continue apace. In terms of using it as a fuel, it seems to have a greater future than fossil fuels that are finite and have worse consequences to the environment.
