Azadeh Mirvakili

The methane steam reforming reaction is highly endothermic, thus the tubes full of catalysts are placed in the furnace. Due to the dominance of radiation heat transfer in the reformer furnace, one of the most important parameters in increasing the efficiency of the reformer is the emissivity coefficient of the furnace wall and tubes, which over time has caused a decrease in the thermal efficiency of the furnace and a decrease in the hydrogen production in the reformer. In this study, the effect of changing the emissivity coefficients of the furnace wall, tunnel and tubes on the synthesis gas production efficiency, especially hydrogen inside the tube and the reformer furnace outlet temperature has been studied. The Zagros Petrochemical reformer furnace was simulated in three dimensions using computational fluid dynamics and validated with industrial data. The results showed that a decrease in the emissivity coefficient during ten years of furnace use causes a 3% decrease in hydrogen production and a 3% increase in residual methane at the tube outlet. To increase the efficiency of the furnace, the use of ceramic coatings was investigated and the results showed that increasing the wall emissivity to 0.9 increased the skin tube temperature and outlet gas by about 8 degrees Celsius, increased hydrogen production by about 6.3 percent, and reduced methane consumption by about 10.2 percent compared to the operating condition.