Charging a Liquid Organic Hydrogen Carrier System with H₂/CO₂ Gas Mixtures

Abstract

Abstract Liquid Organic Hydrogen Carrier (LOHC) systems have attracted growing attention in recent years as efficient way to store and transport hydrogen in the existing infrastructures for liquid fuels. This contribution highlights the additional feature that hydrogenation of the LOHC compound dibenzyltoluene with technical relevant H 2 /CO 2 gas mixtures (up to 30 % CO 2 ) gives access to hydrogen purification and hydrogen storage in one single process step. Alumina supported Rh and Pd catalysts proved to be especially suitable for this task. The rhodium catalysts enabled efficient aromatics hydrogenation in the temperature range of 120 °C to 150 °C with moderate methane formation (CH 4 /CO 2 <0.1 at 150 °C). The palladium catalyst showed the lowest selectivity to methane formation (CH 4 /CO 2 <0.1 at 270 °C) and promising hydrogenation activity at temperatures above 200 °C even in the presence of CO and CO 2 .