Making hydrogen (and carbon) by cracking methane in molten metal
By Gerald Ondrey |
A process that converts methane into hydrogen and carbon black has been developed by researchers at the Institute for Advanced Sustainability Studies (IASS; Potsdam; www.iass-potsdam.de) and the Karlsruhe Institute of Technology (KIT; Karlsruhe, both Germany; www.kit.edu). In a joint project initiated by Nobel Laureate and former IASS scientific director, professor Carlo Rubbia, the proof-of-concept has now been demonstrated.
Based on a novel reactor design proposed by Rubbia, CH4 cracking takes place in molten metal. CH4 is introduced into the bottom of a column full of molten tin at temperatures above 750°C. As the bubbles rise, CH4 is thermally cracked into H2, with carbon black depositing on the bubble surface. The bubbles disintegrate at the top, releasing H2 and leaving behind a powder film of carbon black, which can recovered and sold.
From 2012 to 2015, IASS and KIT have performed experimental campaigns in KIT’s Karlsruhe Liquid Metal Laboratory (KALLA) in a 1.2-m tall reactor made of quartz and stainless steel. In a recent campaign, the reactor operated continuously for two weeks, producing H2 with a 78% conversion rate at temperatures of 1,200°C.
A lifecycle assessment (LCA), performed by IASS and RWTH Aachen University,…