Rate, methane production

Van Ho and Harriott (54) have done similar transient experiments on H2/CO over 10% Ni/Si02, and a result is shown in Fig. 23. Even though the bulk of the nickel is not carbided, the methane production rate rises from zero, as shown. 

N2 injection rapidly increases the methane production rate. The timing and magnitude depends on the distance between injection and production wells, on the natural fracture porosity and permeability, and on the sorption properties. N2 breakthrough at the production well occurs at about half the time required to reach the maximum methane production rate in this ideal case. The N2 content of the produced gas continues to increase until it becomes excessive, i.e., 50% or greater. 

Fig. 4. Methane production rate at 62S K over a Ni(100) catalyst as a function of surface carbon coverage at various reaction conditions. (From /te/ 12.)...

Progressing from each of the above levels to the next saves 2-3 orders of magnitude in financial and time expense. So, for example, if one wished to perform a sensitivity study of methane production rate response to reservoir permeability or hydrate saturation, it is many orders of magnitude easier to do so via a model, than via a field test. 

Displayed in Fig. 5 is the methane production rate from CO and H2 for varying TiOx coverages (12). Reaction rates were measured at a temperature of 553 K, and at H2 and CO partial pressures of 0.67 and 0.33 atm, respectively. With the addition of small amounts of TiOx to the clean Rh surface, a sharp rise in reaction rate is noted. At the maximum corresponding to 0.15 ML [0.50 ML on the corrected scale (9) ], a threefold increase in the rate is observed. Beyond this coverage, the rate decreases monotonically. 

Table 1 shows the mean emission rates (X) and standard errors (s/ V n) for CH4, CO2, and CO from three Reticulitermes and two Gnathermitermes Colonies [19] n is the number of days during which samples which were analyzed during the 55-day showed little variability ( 10%). The variability between days was sometimes much higher. These emission rates are about in the middle of methane production rates reported by... 

Methane production rate, volume (n)/Iiquid volume-day 0.006-0.6 4.4-8.4... 

The yield maximum as a function of temperature is probably due to two effects. At low temperatures the reaction rate of the chemical reaction increases with temperature. At high temperatures the recombination of to with subsequent desorption leads to a lowering of the surface concentration of hydrogen and to a lower methane production rate. 

Fig. 2. Experimental results of methane production rate for the SiO -TiO ( ) and MgO-TiO (O) systems.

The experimental results of the screening tests conducted in unit A are presented in Tables Ha and lib, and for unit B they are given in Tables Ilia and Illb. The specific gas production rates and gasification rates are based on the approximate 4-hr reaction time at 850°C. The results indicate that methane production rates as well as carbon gasification rates can be increased significantly if certain compounds are admixed with the coal feed. 

Figure 2. Effect of temperature on methane production rate using sprayed Raney nickel. Test conditions pressure, 300 psig flow, 2000 std cc/hr N2 water, 5.8 and 1.16 grams/hr.

Potential Methane Production Rates from Select Wetlands... 

In soils, methane production rates are inhibited at soil depths with intense cycling of iron (Ratering and Schnell, 2000). However, the utilization of Fe(III) oxides depends on the appropriate form that is readily available or on microbial communities. In soils with a limited availability of Fe(III) oxides and other electron acceptors, methanogenesis is the dominant pathway to regulating organic matter decomposition and ultimately a major methane source to the atmosphere. 

Potential Methane Production Rates in the Floe and Surface Soils from Select Hydrologic Units of the Everglades... 

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