(298b) Dual Production of Higher Hydrocarbons and Syngas from Greenhouse Gases in a Hydrogen-Permeable Membrane Reactor

Authors: 
Liu, D., University of Maryland
Wachsman, E. D., University of Maryland
Sakbodin, M., University of Maryland College Park
CH4 and CO2 are the largest anthropogenic greenhouse gas (GHG) contributors to climate change. Due to the abundance of natural gas, CH4 will be increasingly utilized for both energy and chemical production with potentially even greater GHG emissions unless methods are developed to increase the efficiency of CH4 conversion, ideally by non-oxidative (no CO2 production) processes. In this talk, we present the first ever direct non-oxidative methane conversion (DNMC) with CO2 to produce value added C2+ hydrocarbons in an integrated DNMC-catalyst/hydrogen-permeable-membrane reactor. Specifically, a direct utilization of CH4 and CO2 to simultaneously produce C2+ hydrocarbons (C2 and aromatics) and syngas (CO and H2) on opposite sides of a mixed ionic-electronic conducting SrCe0.7Zr0.2Eu0.1O3-δ membrane reactor will be discussed. On one side (interior) of the membrane reactor, direct non-oxidative methane conversion (DNMC) over an iron/silica catalyst produces C2+ hydrocarbons and H2. On the other side (outer surface) of the membrane, permeated hydrogen (driving the DNMC reaction) reacts with a CO2 sweep gas to form CO and water via the reverse water gas shift (RWGS) reaction. This novel single hydrogen-permeable membrane reactor simultaneously addresses both reduction of greenhouse gas (CO2 and CH4) emissions as well as production of value-added hydrocarbon products (C2+, CO, and H2) with in situ gas separation. This membrane reactor not only circumvents gas-to-liquid (GTL) thermodynamic limitation of CH4 conversion to C2+ hydrocarbons (without producing byproduct CO2) but in fact uses CO2 as a sweep gas to react with the permeated hydrogen to form CO as a feedstock for additional GTL reactions, thus simultaneous producing value added chemicals while reducing GHG emissions.