Steam reforming, hydrogen reforming or catalytic oxidation, is a method of producing hydrogen from hydrocarbons. On an industrial scale, it is the dominant method for producing hydrogen. Small-scale steam reforming units are currently subject to scientific research, as way to provide hydrogen to fuel cells. Environmental science is the study of the interactions among the physical, chemical and biological components of the environment; with a focus on pollution and degradation of the environment related to human activities; and the impact on biodiversity and sustainability from local and global development. ... Environmental technology or green technology is the application of the environmental sciences to conserve the natural environment and resources, and by curbing the negative impacts of human involvement. ... Before flue gas desulfurization was installed, the emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide. ... Biofuel is any fuel that is derived from biomass — recently living organisms or their metabolic byproducts, such as manure from cows. ... An active compost heap, steaming on a cold winter morning. ... Ecoforestry is forestry that emphasizes holistic practices which strive to protect and restore ecosystems1 instead of traditional forestry that maximizes economic productivity. ... For the physical concepts, see conservation of energy and energy efficiency. ... // Energy development is the ongoing effort to provide sustainable, accessible energy resources through knowledge, skills, and constructions. ... Environmental design is the process of addressing environmental parameters when devising plans, programs, policies, buildings, or products. ... Future energy development faces great challenges due to an increasing world population, demands for higher standards of living, demands for less pollution and a much-discussed end to fossil fuels. ... It has been suggested that this article or section be merged with Sustainable architecture. ... This article or section is incomplete and may require expansion and/or cleanup. ... The international recycling symbol. ... Renewable energy (Non-Conventional Energy) is defined as energy derived from resources that are regenerative or for all practical purposes can not be depleted. ... Generally, remediation means giving a remedy. ... The following page contains a list of different forms of waste treatment Anaerobic digestion ArrowBio Composting Gasification Incineration In-vessel composting Landfill Mechanical biological treatment Mechanical heat treatment Plasma Pyrolysis Recycling Sewage treatment Tunnel composting UASB Windrow composting Categories: | ... This does not cite its references or sources. ... Sustainable Development is a collection of methods to create economic development which protects the environment, relieves poverty, and does not destroy natural capital in the short term at the expense of long term development. ... The following page consist of a list of waste water treatment technologies: Activated sludge Anaerobic digestion Anaerobic lagoon Cesspit Combined sewer overflow Composting toilet Constructed wetland Imhoff tank Floculation Reed bed Septic tank Sequencing batch reactor UASB Aerobic Granular Reactor This list is incomplete; you can help by expanding it. ... Water purification is the removal of contaminants from raw water to produce drinking water that is pure enough for human consumption or for industrial use. ... For the company, see Waste Management, Inc. ... This article is about the chemistry of hydrogen. ... In chemistry, a hydrocarbon is a cleaning solution consisting only of carbon (C) and hydrogen (H). ... A fuel cell is an electrochemical device similar to a battery, but differing from the latter in that it is designed for continuous replenishment of the reactants consumed; i. ...

Industrial Reforming

Steam reforming of natural gas, sometimes referred to as steam methane reforming (SMR) is the most common method of producing commercial bulk hydrogen as well as the hydrogen used in the industrial synthesis of ammonia. It is also the least expensive method.^[1] At high temperatures (700 – 1100 °C) and in the presence of a metal-based catalyst, steam reacts with methane to yield carbon monoxide and hydrogen. Natural gas is a gaseous fossil fuel consisting primarily of methane. ... Methane is a significant and plentiful fuel which is the principal component of natural gas. ... Because of its many uses, ammonia is one of the most highly-produced inorganic chemicals. ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily forms positive ions (cations) and has metallic bonds. ... It has been suggested that this article or section be merged into Catalysis. ... Carbon monoxide, with the chemical formula CO, is a colourless, odourless and tasteless gas. ...

CH₄ + H₂O → CO + 3 H₂

The United States produces nine million tons of hydrogen per year, mostly with steam reforming of natural gas. The worldwide ammonia production, using hydrogen derived from steam reforming, was 109 million metric tonnes in 2004.^[2] Methane is a significant and plentiful fuel which is the principal component of natural gas. ... Impact of a drop of water. ... Carbon monoxide, with the chemical formula CO, is a colourless, odourless and tasteless gas. ... This article is about the chemistry of hydrogen. ... A ton(ne) (symbol t) is a unit of mass. ...

This SMR process is quite different from and not to be confused with catalytic reforming of naphtha, an oil refinery process that also produces significant amounts of hydrogen along with high octane gasoline. A catalytic reforming process converts a feed stream containing paraffins and naphthenes into aromatics to be used either as a motor fuel, such as gasoline or as a source for specific aromatic compounds for use in petrochemicals production. ... Naphtha is a group of various volatile flammable liquid hydrocarbon mixtures used primarily as feedstocks in refineries for the reforming process and in the petrochemical industry for the production of olefins in steam crackers. ... View of Shell Oil Refinery in Martinez, California. ... A gas station pump offering five different octane ratings. ... Gasoline, also called petrol, is a petroleum-derived liquid mixture consisting mostly of hydrocarbons and enhanced with benzene or iso-octane to increase octane ratings, used as fuel in internal combustion engines. ...

A great deal of ethylene is produced by a non-catalytic process called "steam cracking" which cracks (i.e., reforms) large hydrocarbon molecules into smaller molecules). In the year 2003, there was 97,000,000 metric tons of ethylene (used to produce polyethylene and a host of other petrochemical chemicals) manufactured worldwide by the steam cracking of various hydrocarbons (methane, ethane, LPG, naphtha, and fuel oils). Ethylene (or IUPAC name ethene) is the chemical compound with the formula CH2CH2. ... Cracking-divides a group’s voters into other districts, where they will be ineffective minorities; and kidnapping places two incumbents from the same party in the same district. ... Ethane is a chemical compound with chemical formula C2H6. ... LPG might be an initialism or abbreviation for: Liquified petroleum gas Laboratoire de Planetologie, Grenoble, France Literary Press Group of Canada Landwirtschaftliche Produktionsgenossenschaft (German, obsolete/historical) Long period grating This page concerning a three-letter acronym or abbreviation is a disambiguation page — a navigational aid which lists other pages that... Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. ...

Fueling fuel cells

Steam reforming of liquid hydrocarbons is seen as a potential way to provide fuel for fuel cells. The basic idea is that for example a methanol tank and a steam reforming unit would replace the bulky pressurized hydrogen tanks that would otherwise be necessary. This might mitigate the distribution problems associated with hydrogen vehicles. A fuel cell is an electrochemical device similar to a battery, but differing from the latter in that it is designed for continuous replenishment of the reactants consumed; i. ... Methanol, also known as methyl alcohol, wood alcohol or wood spirits, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a distinctive odor that is somewhat milder and sweeter than ethanol (ethyl alcohol). ... It has been suggested that this article or section be merged with Hydrogen vehicle. ...

However, there are several challenges associated with this technology:

• Steam reforming can utilize liquid hydrocarbon fuels, such as ethanol and bio-diesel, but these fuels will not be available in large enough quantities to make hydrogen, especially when vehicles are being promoted that can run on them directly.
• The reforming reaction takes place at high temperatures, making it slow to start up and requiring costly high temperature materials.
• Sulphur compounds present in the fuel poison certain catalysts, making it difficult to run this type of system from ordinary gasoline. Some new technologies have overcome this challenge, however, with sulphur-tolerant catalysts.
• The carbon monoxide (CO) produced by the reactor poisons the fuel cell, making it necessary to include complex CO-removal systems.
• The thermodynamic efficiency of the process is between 70% and 85% (LHV basis) depending on the purity of the hydrogen product.
• The biggest problem for reformer based systems remains the fuel cell itself, in terms of both cost and durability. The catalyst used in the common polymer-electrolyte-membrane fuel cell, the device most likely to be used in transportation roles, is very sensitive to any leftover carbon monoxide in the fuel, which some reformers do not completely remove. The membrane is poisoned by the carbon monoxide and its performance degrades.
• The catalyst is frequently very expensive.

The reformer–fuel-cell system is still being researched but in the near term, systems would continue to run on existing fuels, such as natural gas or gasoline or diesel, but there is an active debate about whether using these fuels to make hydrogen is beneficial, when global warming is such an issue. The overall cost of making, transporting and storing the hydrogen fuel is also a key issue. For the chemical element see: sulfur. ... Gasoline, also called petrol, is a petroleum-derived liquid mixture consisting mostly of hydrocarbons and enhanced with benzene or iso-octane to increase octane ratings, used as fuel in internal combustion engines. ... Thermodynamic efficiency (e) is defined as: where W is the absolute value of the work done in one thermodynamic cycle. ... An artificial membrane, also called a synthetic membrane, is a membrane prepared for separation tasks in laboratory and industry. ...

The process

The chemical reactions that take place are:

C_nH_m + n H₂O → n CO + (m/2 + n) H₂

CO + H₂O → CO₂ + H₂

The produced carbon monoxide can combine with more steam to produce further hydrogen via the water gas shift reaction. The water gas shift reaction is an organic reaction in which water and carbon monoxide react to form carbon dioxide and hydrogen (water splitting) CO + H2O → CO2 + H2 The water gas shift reaction is part of steam reforming of hydrocarbons and is involved in the chemistry of catalytic converters While...

The process is endothermic (consumes heat). In thermodynamics, the word endothermic describes a process or reaction that absorbs energy in the form of heat. ...

References

Physics Today magazine, created in 1948, is the flagship publication of The American Institute of Physics. ... 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ...

See also

• Hydrogen technologies
• Methane
• Natural gas
• Biogas