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This is sometimes called the reverse water–gas shift reaction. [20] Water gas is defined as a fuel gas consisting mainly of carbon monoxide (CO) and hydrogen (H 2). The term 'shift' in water–gas shift means changing the water gas composition (CO:H 2) ratio. The ratio can be increased by adding CO 2 or reduced by adding steam to the reactor.
The water gas shift reaction is the reaction between carbon monoxide and steam to form hydrogen and carbon dioxide: CO + H 2 O ⇌ CO 2 + H 2. This reaction was discovered by Felice Fontana and nowadays is adopted in a wide range of industrial applications, such as in the production process of ammonia, hydrocarbons, methanol, hydrogen and other chemicals.
Natural gas has a high hydrogen to carbon ratio, so the water-gas shift is not needed for cobalt catalysts. Cobalt-based catalysts are more sensitive than their iron counterparts. Illustrative of real world catalyst selection, high-temperature Fischer–Tropsch (HTFT), which operates at 330–350 °C, uses an iron-based catalyst.
The reaction can be carried out over a copper-based catalyst, but the reaction mechanism is dependent on the catalyst. For a copper-based catalyst two different reaction mechanisms have been proposed, a decomposition-water-gas shift sequence and a mechanism that proceeds via methanol dehydrogenation to methyl formate.
Methanol is made from methane (natural gas) in a series of three reactions: Steam reforming CH 4 + H 2 O → CO + 3 H 2 Δ r H = +206 kJ mol −1 Water shift reaction CO + H 2 O → CO 2 + H 2 Δ r H = -41 kJ mol −1 Synthesis 2 H 2 + CO → CH 3 OH Δ r H = -92 kJ mol −1. The methanol thus formed may be converted to gasoline by the Mobil ...
Steam can be added to the reaction in order to increase the generation of H 2, via the water-gas shift reaction (WGS) and/or steam methane reforming. The CLR process can produce a syngas with a H 2:CO molar ratio of 2:1 or higher, which is suitable for Fischer–Tropsch synthesis, methanol synthesis, or hydrogen production. The reduced oxygen ...
Hydrocarbonate is an archaic term for water gas composed of carbon monoxide and hydrogen generated by passing steam through glowing coke.Hydrocarbonate was classified as a factitious air and explored for therapeutic properties by some eighteenth-century physicians, including Thomas Beddoes and James Watt. [5]
In chemistry, a catalytic cycle is a multistep reaction mechanism that involves a catalyst. [1] The catalytic cycle is the main method for describing the role of catalysts in biochemistry, organometallic chemistry, bioinorganic chemistry, materials science, etc.