Damköhler number as a descriptive parameter in methanol steam reforming and its integration with absorption heat pump system

Studies on the kinetics of methanol steam reforming (MSR) reaction have been extensively carried out in these past decades. However, in order to get a more thorough understanding of the MSR performance, it is necessary to integrate the reaction kinetics of MSR with the reactor design/operating parameters. This paper presents such works and employs Damköhler number (Da) to conveniently describe the trade-off between kinetics (reaction time scale) and operating parameters (residence time scale) of the MSR system. The correlation of Da and methanol conversion was also experimentally verified. Furthermore, feasibility criterion as a parameter to describe energy gain obtained by MSR reaction over the energy required by absorption heat pump (AHP) system was viewed, and its correlation with Da was investigated. Some results showed that even at various combinations of GHSV and MSR reaction temperature, the Da – methanol conversion empirically have a similar typical curve. On the other hand, for the combined AHP–MSR system, changing the value of Da, either by changing the GHSV or MSR reaction temperature, results in different profiles of feasibility criterion and hydrogen production rate.

► Kinetics of methanol steam reforming is correlated with reactor design parameters.
► Damköhler number (Da) is calculated and experimentally verified.
► Da – conversion has a typical curve at various GHSV and temperature combinations.
► Changing Da results in different profiles of energy gain and production rate.