# Optimization, Characterization, and Selection of Iron Ores as Oxygen Carriers for Application in Chemical Looping Processes

## TL;DR

This study explores the use of iron ores from Brazil as oxygen carriers in chemical looping processes for CO2 capture and utilization.

## Contribution

The study identifies and characterizes iron ore samples from Brazil as promising oxygen carriers for chemical looping processes.

## Key findings

- Selected iron ore samples showed high reactivity and oxygen transport capacity suitable for chemical looping processes.
- Samples FeHP, FeHJ, FeHC, FeLC, FeTiHL, and FeTiHM demonstrated excellent cyclic stability and performance.
- The materials are suitable for operation in the 800–1100 °C temperature range typical for chemical looping.

## Abstract

The industrial viability of chemical looping technology
is directly
linked to the development of oxygen carriers (OCs) that meet the operational
requirements of the process. This study investigates the optimization,
characterization, and selection of iron ores from different regions
of Brazil as potential OCs for chemical looping applications. A total
of 13 samples were analyzed, including 11 predominantly composed of
hematite and 2 of ilmenite. These materials were characterized through
physicochemical, morphological, and structural analyses using techniques
such as X-ray diffraction (XRD), X-ray fluorescence (XRF), temperature-programmed
reduction (TPR), and scanning electron microscopy–energy-dispersive
spectroscopy (SEM-EDS). The samples exhibited good mechanical strength
(≥2.2 N), oxygen transport capacity ranging from 1.21% to 4.90%,
and high reactivity during redox cycles with methane and hydrogen.
Notably, the FeHP, FeHJ, FeHC, FeLC, FeTiHL, and FeTiHM samples demonstrated
outstanding performance in terms of reactivity, cyclic stability,
and oxygen transport capacity, showing suitability for operation in
the typical temperature range of 800–1100 °C for CL processes.
These findings highlight the potential of applying the selected materials
in chemical looping technologies, offering sustainable and cost-effective
alternatives for CO2 capture and utilization.