Methane sulfurization

Extensive research has been conducted on catalysts that promote the methane—sulfur reaction to carbon disulfide. Data are pubhshed for sihca gel (49), alurnina-based materials (50—59), magnesia (60,61), charcoal (62), various metal compounds (63,64), and metal salts, oxides, or sulfides (65—71). Eor a sihca gel catalyst the rate constant for temperatures of 500—700°C and various space velocities is (72)... 

A disadvantage of the hydrocarbon—sulfur process is the formation of one mole of hydrogen sulfide by-product for every two atoms of hydrogen in the hydrocarbon. Technology for efficient recovery of sulfur values in hydrogen sulfide became commercially available at about the same time that the methane—sulfur process was developed. With an efficient Claus sulfur recovery unit, the hydrocarbon—sulfur process is economically attractive. 

Brief Plant Description. Oxygen is reacted with a feedstock/steam mixture in a Texaco or Shell generator to produce a synthesis gas with a low H /CO ratio together with carbon dioxide, methane, sulfur compounds and a small percentage of unreacted carbon. 

Another example of crystals containing more than one component is provided by the clathrates. In clathrates of, 3-quinol, three quinol molecules are hydrogen bonded together to form an approximately spherical cavity of radius 4 A (Figure 15.13). Any molecule of appropriate size such as oxygen, nitrogen, krypton, xenon, methane, sulfur dioxide, or methyl alcohol can be trapped, and if it is not disordered within the clathrate, its location and orientation can be determined in the crystalline state by X-ray diffraction methods. In most cases, when a clathrate is... 

These processes are the retort process and the electrothermal process [116]. The third process is the methane-sulfur process. 

Figure 4.7 Carbon disulfide via the methane-sulfur process. Source [121].

Most countries are currently using the methane-sulfur process. Worldwide production of carbon disulfide is about 235,000 ton/yr in 1991 [125]. This is the only process used in the United States [126]. The United States used a total of 108,000 tons in 1990 [127]. A typical methane-sulfur plant tends to produce 50,000-200,000 ton/yr of carbon disulfide as compared to a coal-sulfur plant which produces about 5,000 ton/yr [128]. 

In addition to carbon dioxide, the concerned ga.ses include nitrous oxide, methane, sulfur hexafluoride, hydrofluorocarbons, and pertluorocarbons. 

Neon, helium, methane, sulfur dioxide, hydrogen, and other minor gases 0.00003... 

Table 6.4 Numerical results from each of the FFF in computations for the fugacity of methane(l) in an equimolar methane-sulfur hexafluoride mixture at 60°C, 20 bar...

In addition to measurements of the humidity of atmospheric air, which is the most frequent, measurements are also made in such technologically important gases as argon, helium, neon, nitrogen, oxygen, methane, sulfur dioxide, refrigerants, and natural gas. 

Methane Sulfur Carbon Disulfide Hydrogen Sulfide... 

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