Intensified processes for CO2 conversion to sustainable synthetic fuels

Introduction

Developing intensified catalytic processes for CO2 conversion may drive their implementation at CO2-producing sites, counteracting current practices of emitting CO2 and waste gases. Converting CO2 to synthetic fuels is a win-win scenario as they are used as sustainable aviation fuel.

Technology Overview

A leading technology to convert CO2 to synthetic fuels proceeds indirectly via Reverse Water Gas Shift (RWGS) and Fischer-Tropsch Synthesis (FTS). CO2 is first reduced to CO via RWGS and then converted to hydrocarbons via FTS. Based on current chemical engineering practices, four unit operations (two reactors and two intermediate separations) are required.

Objectives of IntensifiedCO2 Technology

The ambition of the IntensifiedCO2 technology is to intensify the current practice through the reduction of unit operations, without compromising on selectivity towards synthetic fuels. The objectives are to:

1. Eliminate two separation units for CO2 and H2O.
2. Consolidate two reactors into a single bifunctional (RWGS and FTS) reactor.

As such, the IntensifiedCO2 technology will be the first demonstration of metallic cobalt catalysts ‘converting’ CO2 to synthetic fuels in a single reactor.

Catalyst Performance Challenges

Metallic cobalt catalysts are industrial FTS catalysts but produce mainly methane from CO2. Attempts thus far on tuning cobalt phases to attain synthetic fuels have been unsuccessful, signaling the need for a radical strategy as proposed in IntensifiedCO2.

Innovative Approach

My innovative approach involves coaxing a metallic cobalt FTS catalyst to disregard the presence of CO2 and H2O within the reactor, ensuring its catalytic performance mirrors that of synthesis gas (a mixture of CO and H2) conditions.

Conceptual Framework

Ideally, undesired species stay in the reactor's mass transfer zone, while desired species interact in the catalyst's adsorption/reaction/desorption zone. This concept of customizing the catalyst’s environment in the reactor stands in stark contrast to the common approaches of tailoring catalyst material and active sites, signifying a paradigm shift in catalysis research.