Reformer outlet temperature

Increased Process Air Supply to the Secondary Reformer. Decreased heat supply in the primary reformer means that increased internal firing is necessary to achieve approximately the same degree of total reforming. A somewhat higher methane slip (and thus a lower secondary reformer outlet temperature) is acceptable and preferable in this type of process. This is because methane is removed in the final purification.53... 

The microalloy tubes allow increased flux rates and higher reformer outlet temperatures. This in turn can make it possible to reduce the steam-to-carbon ratio while the hydrogen purity remains the same.86... 

A variety of syngas compositions, ready to be fed to the membrane modules, can be produced by acting on the steam/carbon ratio and on the reformer outlet temperature through the variation of the firing of two hot gas generators. This makes it possible to study the role played by partial pressures of the main components in separation performance. The effect of temperature on membrane permeance at fixed reformer working conditions may be studied by varying the temperature set point of two air coolers placed at the inlet of the membrane modules. 

Methane and hydrogen content at the outlet of the reforming reactor as a function of reformer outlet temperature. 

At lower S/C ratios, the methane conversion will be reduced at constant outlet temperature. Therefore, the reformer outlet temperature is increased to achieve methane conversion of >96%. In plants for CO or synthesis gas, the process outlet temperature is typically selected between 900 and 960°C. These severe conditions require the use of a specially designed process outlet system, which transfers the product to the process gas waste heat boiler. 

This flue gas maldistribution, in turn, may lead to overheating of reactor tubes and wide distributions of reformer outlet temperatures. 

In principle, a low steam-to-carbon ratio increases the amount of unconverted methane from the reformer (Figure 1.8), but this can be compensated for by increasing the reformer outlet temperature, typically to 920°C. In synthesis plants, the unconverted methane flows downstream with the synthesis gas. Unconverted methane thus implies a larger syngas unit and results in restrictions on recycle ratios in the synthesis because of accumulation of the inert methane in the synthesis gas, which reduces the partial pressures of the syngas components. 

Figure 2. Maximum stack power and fuel utilization at different operating points and CH4 content of the biogas. Fuel gas composition was adjusted on the basis of thermodynamic simulations with a reformer outlet temperature of 700 °C ...

Table 5.2 Mass flow rates m, reformer outlet temperature T, and ...

Subsequently, a meso-scaled combined reformer/catalytic combustor with 10-kW power output was realised by GM/OPEL, which was not presented in detail. For this bigger reactor, the carbon monoxide content of the reformate increased, as expected, with increasing reformer outlet temperature from 0.5% at 250 °C to 2% at 300 °C. Increasing the residence time increased the carbon monoxide concentration of the reformate due to the reverse water-gas shift reaction. Increasing the S/C ratio from 1.2 to 1.8 at a 300 °C reaction temperature increased the hydrogen concentration in the reformate slightly from 72 to 73% and decreased the carbon monoxide content from 1.5 to 1.0%, which originated from the beneficial effect of steam addition on the equilibrium of the water-gas shift reaction. 

At this point in time, the temperature of the reformer feed amounted to about 110 ° C and the reformate left the reactor at a temperature of220 °C. The full reformate flow was achieved after 30 s and the temperature of the reformate was then 500 °C. After 60 s the steam left the evaporator at a temperature of400 °C and the reformate outlet temperature was already 700 °C. The total mass of a future 50 kW fuel processor was estimated to be 55 kg, which corresponded to a total energy demand of 7 MJ for startup heating. From this value, the power demand of an air blower, which had to provide some 22 m min air to the system during start-up, was calculated to about 1 kW. As this power would have been required only during the rapid system start-up (60 s) a normal battery would have been sufficient as the power supply. An efficiency of 78% was calculated for the entire future fuel processor. 

The above ratios are based on t5q)ical reformer outlet temperatures and pressures for each technology. The reformer outlet temperature is t5q)ically set by the residual methane requirement. The reformer outlet pressure is t5q)ically... 

ATR and POX plants can run at much higher pressures. For example, some plants require synthesis gas at about 800 psig this can be supplied directly from an ATR or POX without synthesis gas compression. TEMPERATURE - SMR plants typically run at reformer outlet temperatures of 1550 to 1700°F. 

Ammonia formation is lessened due to the fact that the residence time of the steam methane reformer is designed for hydrogen production not ammonia production with recycle. In an NH3 plant, the ammonia is considered to be at equilibrium in a secondary reformer that is operating approximately 300°F to 500°F higher than a traditional steam methane reformer. Therefore for calculations, the worst case for ammonia production in a hydrogen plant can be assumed to be equilibrium at the reformer outlet temperature plus an additional 300°F. 

---