As a promising approach for carbon dioxide capture, chemical looping combustion has been extensively investigated for more than two decades. However, the chemical looping strategy can be and has been extended well beyond carbon capture. In fact, significant impacts on emission reduction, energy conservation, and value-creation can be anticipated from chemical looping beyond combustion (CLBC). This article aims to demonstrate the versatility and transformational benefits of CLBC. Specifically, we focus on the use of oxygen carriers or redox catalysts for chemical production – a $4 trillion industry that consumes 40.9 quadrillion BTU of energy. Compared to state-of-the-art chemical production technologies, we illustrate that chemical looping offers significant opportunities for process intensification and exergy loss minimization. In many cases, an order of magnitude reduction in energy consumption and CO2 emission can be realized without the needs for carbon dioxide capture. In addition to providing various CLBC examples, this article elaborates on generalized design principles for CLBC, potential benefits and pitfalls, as well as redox catalyst selection, design, optimization, and redox reaction mechanism.

/pdf/chemical-looping-beyond-combustion-a-perspective-2ohy8fd521.pdf

Chemical looping beyond combustion – a perspective

Natural gas (with methane as its main component) provides an attractive energy source because of its large abundance and its high heat of combustion per mole of carbon dioxide generated. However, the emissions released from the conventional flame combustion (essentially NOx) have harmful impacts on the environment and the human health. Within the scope of rational and clean use of fossil energies, the catalytic combustion of natural gas appears as one of the most promising alternatives to flammable combustion. The presence of catalysts enables complete oxidation of methane at much lower temperatures (typically 500 °C), so that the formation of pollutants can be largely avoided. This work presents a literature review on the catalytic methane combustion. Various aspects are discussed including the catalyst types, the reaction mechanisms and kinetic characteristics, effects of various influencing operational factors and different reactor types proposed and tested. This paper may serve as an essential reference that contributes to the development of well-designed reactors, equipped with appropriate catalysts, and under well-handled operating conditions to realize the favorable (kinetic) performance, for their future applications and propagation in different industrial sectors.

A review on catalytic methane combustion at low temperatures: Catalysts, mechanisms, reaction conditions and reactor designs

Chemical looping technology enables achievement of the simultaneous feedstock conversion and product separation without additional processes via circulating solid intermediates (so-called oxygen/ni...

Chemical Looping Conversion of Gaseous and Liquid Fuels for Chemical Production: A Review

Chemical‐Looping Conversion of Methane: A Review

Biomass chemical looping gasification (BCLG) is a novel and promising technology for syngas production, in which lattice oxygen in oxygen carriers (OCs) reacts with biomass. OCs can continuously su...

Review of Biomass Chemical Looping Gasification in China

CeO2–Fe2O3 mixed oxides are very attractive as catalysts for catalytic oxidation. Herein, we report the structural dependence of the Ce1–xFexO2−δ catalysts for CH4 combustion and CO oxidation via c...

Ruidong Xu

Papers

Chemical Looping Conversion of Gaseous and Liquid Fuels for Chemical Production: A Review

Chemical‐Looping Conversion of Methane: A Review

Enhanced CH4 and CO Oxidation over Ce1–xFexO2−δ Hybrid Catalysts by Tuning the Lattice Distortion and the State of Surface Iron Species

Ce1-xFexO2-δ catalysts for catalytic methane combustion: Role of oxygen vacancy and structural dependence

Design of hybrid oxygen carriers with CeO2 particles on MnCo2O4 microspheres for chemical looping combustion