Thermal Decomposition of Methane in Capillary Tubes of Different Materials: Corundum, Titanium, Nickel, and Stainless Steel

The effect of capillary tube material on the process of thermal decomposition of methane at 1100 degrees C and methane supply at a rate of 2 L/h without the use of catalysts was studied. The materials used were corundum, titanium, nickel, and stainless steel. The reactor was a capillary tube, which was heated from the outside with a propane burner; the length of the heating zone was about 8 cm. It was found that the efficiency of methane decomposition decreases in a number of materials: Al2O3 > Ni > Ti > stainless steel. The highest hydrogen yield (73.35 vol. %) was achieved in the experiment with a corundum tube with an inner diameter of 4 mm, and the lowest (27.75 vol. %) was achieved in the experiment with a stainless steel tube with a diameter of 6 mm. Nickel and titanium showed worse hydrogen yield results than corundum: for nickel, the volume content of hydrogen after pyrolysis was 71.27%, and for titanium, 41.51%.

Automated summary

The effect of capillary tube material on the process of thermal decomposition of methane was studied, and it was found that corundum showed the highest efficiency while stainless steel showed the lowest efficiency.