Liquefied Hydrogen Tankers: Cryogenic liquefaction is a process that cools hydrogen to a temperature where it becomes a liquid. High-Pressure Tube Trailers: Transporting compressed hydrogen gas by truck, railcar, ship, or barge in high-pressure tube trailers is expensive and used primarily for distances of 200 miles or less. These pipelines are located near large petroleum refineries and chemical plants in Illinois, California, and the Gulf Coast. Pipeline: This is the least-expensive way to deliver large volumes of hydrogen, but the capacity is limited because only about 1,600 miles of pipelines for hydrogen delivery are currently available in the United States. The initial rollout for vehicles and stations focuses on building out these distribution networks, primarily in southern and northern California.Ĭurrently, hydrogen is distributed through three methods:
The infrastructure needed for distributing hydrogen to the nationwide network of fueling stations required for the widespread use of fuel cell electric vehicles still needs to be developed. Most hydrogen used in the United States is produced at or close to where it is used-typically at large industrial sites. Learn more about hydrogen production from the Hydrogen and Fuel Cell Technologies Office. Government and industry research and development projects are reducing the cost as well as the environmental impacts of hydrogen production technologies. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional transportation fuels. Today, almost all the hydrogen produced in the United States is used for refining petroleum, treating metals, producing fertilizer, and processing foods.
The major hydrogen-producing states are California, Louisiana, and Texas. Photoelectrochemical Water Splitting: Photoelectrochemical systems produce hydrogen from water using special semiconductors and energy from sunlight. Photobiological Water Splitting: Microbes, such as green algae, consume water in the presence of sunlight and produce hydrogen as a byproduct. High-Temperature Water Splitting: High temperatures generated by solar concentrators or nuclear reactors drive chemical reactions that split water to produce hydrogen. Several hydrogen production methods are in development: Renewable Liquid Reforming: Renewable liquid fuels, such as ethanol, are reacted with high-temperature steam to produce hydrogen near the point of end use.įermentation: Biomass is converted into sugar-rich feedstocks that can be fermented to produce hydrogen. Power-to-hydrogen projects are taking off, using excess renewable electricity, when available, to make hydrogen through electrolysis. If the electricity is produced by renewable sources, such as solar or wind, the resulting hydrogen will be considered renewable as well, and has numerous emissions benefits. The resulting synthesis gas contains hydrogen and carbon monoxide, which is reacted with steam to separate the hydrogen.Įlectrolysis: An electric current splits water into hydrogen and oxygen.
This converts the coal or biomass into gaseous components-a process called gasification. Natural gas reforming using steam accounts for the majority of hydrogen produced in the United States annually.Ī synthesis gas can also be created by reacting coal or biomass with high-temperature steam and oxygen in a pressurized gasifier. This method is the cheapest, most efficient, and most common. The carbon monoxide is reacted with water to produce additional hydrogen. Natural Gas Reforming/Gasification: Synthesis gas-a mixture of hydrogen, carbon monoxide, and a small amount of carbon dioxide-is created by reacting natural gas with high-temperature steam.
There are several ways to produce hydrogen: Several projects are underway to decrease costs associated with hydrogen production. The environmental impact and energy efficiency of hydrogen depends on how it is produced. Hydrogen can be produced from diverse, domestic resources, including fossil fuels, biomass, and water electrolysis with electricity. Hydrogen fuel combines with oxygen from the air through a fuel cell, creating electricity and water through an electrochemical process. Although abundant on earth as an element, hydrogen is almost always found as part of another compound, such as water (H 2O) or methane (CH 4), and it must be separated into pure hydrogen (H 2) for use in fuel cell electric vehicles.
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