CoS, synthesis

Reactions of Synthesis Gas. The main hydrogen manufacturing processes produce synthesis gas, a mixture of H2 and CO. Synthesis gas can have a variety of H2-to-CO ratios, and the water gas shift reaction is used to reduce the CO level and produce additional hydrogen, or to adjust the H2 to-CO ratio to one more beneficial to subsequent processing (69) ... 

Liquid-Phase Methanation of High Concentration CO Synthesis Gas... 

This H2 + CO synthesis gas can be processed for sulfur-removal (Sulfinol), CO-shift (HTS/LTS), CO2-removal, and methanation to produce a high purity (>98% vol H2) hydrogen. 

The relative amounts of H2 and CO (synthesis gas stoichiometric ratio) are immaterial at this juncture since application of water-gas-shift (WGS) moves carbon monoxide to hydrogen or vice versa if required. 

Samples of both K-promoted and K-free catalysts were pretreated in situ under reaction conditions in a 1 1 H2 CO synthesis gas at either (1) 215°C for 18 hours or (2) 245°C for 6 hours before TPSR with hydrogen. Based on previous CSTR reaction studies [8], these two reaction regimes were chosen to be representative of (1) steady-state reaction under mild conditions without deactivation and (2) severe reaction conditions involving significant deactivation. 

In a typical fixed-bed synthesis reactor (Figure la), the catalyst is packed into about 10,000 one-inch (2.5 cm) tubes, and the synthesis gas is sent through this array of tubes. The tubes are water-cooled, and much of the heat given off by the reactor is captured as process steam. However, heat transfer within the packed tubes is poor, and if a low Ha-to-CO synthesis gas were used, carbon would be deposited on the catalyst surfaces, resulting in severe catalyst deactivation and loss of operability. 

The C-terminal domain of NifB is a NifX-like domain found in proteins capable of binding FeMoco and NifB cofactor (NifB-co). It has been proposed that this domain may either (1) act as a scaffold for the SAM-dependent formation of NifB-co via the actions of the N-terminal radical SAM domain or (2) bind and transfer the NifB-co to the next set of proteins in FeMoco synthesis.Only additional biochemical studies will shed light on the exact role of SAM in NifB-co synthesis and clarify if the actions of this radical SAM protein result in the incorporation of the unidentified C, N, or O atom into FeMoco. 

Hall et al. found that when a 50 50 H2 CO synthesis gas containing 1.4 percent radioactive CO2 was passed over an iron catalyst at 240 °C, very little CO2 was converted to CO, or to hydrocarbons. Thus, under these... 

Values of AEa(kcal/g mol), X and Y are given in the table, along with a number designated Mult, which is a statistical measure of the precision with which the equation represents the experimental data. Rather than reporting values of K, turnover numbers have been calculated for a temperature of 300°C and 3 H2 l CO synthesis gas (note the difference in pressures). These are reported in Table II, where they are compared with related data from the literature 11,12). 

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