COX-free LOHC dehydrogenation in a heatpipe reformer highly integrated with a hydrogen burner

Abstract

We introduce a thermally self-sustained reactor concept highly integrated with a heat source to produce hydrogen (H-2) stored in methylcyclohexane (MCH), the liquid organic hydrogen carrier (LOHC). This work has a great potential to promote the use of LOHC for COx-free H-2 production for on-board or mobile applications. To this end, the heat-pipe dehydrogenator, an H-2 burner, and a thermal management module are developed. We initially perform a numerical simulation to optimize reactor wall materials and configuration and experimentally test them to reveal the feasibility of such a highly integrated system to maintain uniform reaction temperature at 320 - 360 degrees C, optimal for MCH dehydrogenation. In the proposed design, the heat required for the reaction is provided by the combustion of a part of released H-2, and transferred via a gas-liquid organic phase-change material (PCM). In the as-developed H-2 generator with 50.4 NLH2/h (equivalent to 138.5 WLHV-basis), we achieve a high reforming efficiency of 80% with an MCH conversion of > 99.7%. We expect the as-developed system to be a stepping stone to expanding the use of LOHC in versatile applications requiring carbon-free H-2 storage and production after further engineering efforts to enhance heat recovery and thermal circulation.