Enhancement of partial oxidation reformer by the free-section addition for hydrogen production

Hydrogen production by the partial oxidation combustion in porous media provides an efficient utili-zation for renewable biogas. In this paper, the free section with lengths of 0, 5,10,15 mm were designed in the middle of two-section porous media respectively. The effects of free section addition on the temperature distribution and methane conversion were investigated to determine the optimal burner parameters at the operating conditions of different velocities and equivalence ratios. Results indicate that the highest temperature appeared in the free length of 10 mm but the maximum of H-2 energy conversion efficiency was in that of 15 mm. For the Al2O3 ceramic foam of 20 PPI, the better heat recirculation and preheating effect were shown between the gas and solid. However, the productions of H-2 and CO at the 10 PPI burner reached the highest. With the increasing of equivalence ratio from 1.4 to 1.8, the energy conversion efficiency of syngas rose from 41% to 61% with the 15 mm free length. The appropriate free section addition contributes to improving the reforming efficiency, which provides a new way for the burner design. (c) 2022 Elsevier Ltd. All rights reserved.