**Heather D. Willauer 1,\*, Matthew J. Bradley 2, Je**ff**rey W. Baldwin 3, Joseph J. Hartvigsen 4, Lyman Frost 4, James R. Morse 1, Felice DiMascio 5, Dennis R. Hardy <sup>6</sup> and David J. Hasler <sup>5</sup>**


Received: 26 June 2020; Accepted: 18 August 2020; Published: 26 August 2020

**Abstract:** Low-cost iron-based CO2 hydrogenation catalysts have shown promise as a viable route to the production of value-added hydrocarbon building blocks. It is envisioned that these hydrocarbons will be used to augment industrial chemical processes and produce drop-in replacement operational fuel. To this end, the U.S. Naval Research Laboratory (NRL) has been designing, testing, modeling, and evaluating CO2 hydrogenation catalysts in a laboratory-scale fixed-bed environment. To transition from the laboratory to a commercial process, the catalyst viability and performance must be evaluated at scale. The performance of a Macrolite®-supported iron-based catalyst in a commercial-scale fixed-bed modular reactor prototype was evaluated under different reactor feed rates and product recycling conditions. CO2 conversion increased from 26% to as high as 69% by recycling a portion of the product stream and CO selectivity was greatly reduced from 45% to 9% in favor of hydrocarbon production. In addition, the catalyst was successfully regenerated for optimum performance. Catalyst characterization by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), along with modeling and kinetic analysis, highlighted the potential challenges and benefits associated with scaling-up catalyst materials and processes for industrial implementation.

**Keywords:** carbon dioxide; hydrogenation; catalyst; gas hourly space velocity (GHSV); fixed-bed reactor
