Enhancement of methanol steam reforming in a tubular fixed-bed reactor with simultaneous heating inside and outside

The fixed-bed reactor is a common hydrogen supply device for mobile fuel cell equipment. However, the fixed-bed reactor suffers from an apparent cold spot problem, restricting the hydrogen production for the methanol steam reforming (MSR). This paper proposes a tubular fixed-bed reactor (TFBR) with helical fins around the inner heating pipe (TFBRH). Then, the effects of geometric parameters (pitch, height, and width) of the helical fins, and the temperature, the inlet flow velocity, and the steam to methanol (S/C) molar ratio on the methanol conversion are numerically studied. The results show that the cold spot problem in the reactor could be significantly improved. Compared with the TFBR, the surface temperature non-uniformity Uϕ is reduced by 48.97% due to the coupling effect of the simultaneous heating inside and outside and the helical fins. Furthermore, the results demonstrate that increasing the height and reducing the pitch of helical fins is beneficial for enhancing the methanol conversion. Compared with the TFBR, the methanol conversion of TFRBH could be improved by 8.47% at a temperature of 523 K.