Search results
Results From The WOW.Com Content Network
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 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.
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.
An illustrative example is the effect of catalysts to speed the decomposition of hydrogen peroxide into water and oxygen: . 2 H 2 O 2 → 2 H 2 O + O 2. This reaction proceeds because the reaction products are more stable than the starting compound, but this decomposition is so slow that hydrogen peroxide solutions are commercially available.
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.
Water-gas shift. CO + H 2 O -> H 2 + CO 2. Hydro-gasification. 2H 2 + C -> CH 4. The combination of carbon (C) from the carbon feedstock, water (H 2 O) from steam, and the catalyst, produces pure methane and a pure stream of carbon dioxide (CO 2) which is 100% captured in the system and available for sequestration. The overall reaction is ...
For example, an increase in pressure due to decreasing volume causes the reaction to shift to the side with fewer moles of gas. [ 16 ] The reaction yield stabilizes at equilibrium but can be increased by removing the product from the reaction mixture or changed by increasing the temperature or pressure.
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 ...