Work

Experimental study on oxyfuel-combustion of solid recovered fuel using ilmenite as bed material in a 1 MWth fluidized bed reactor

Year: 2025

Type: article

Abstract: The transition from coal-based power generation to carbon-neutral alternatives remains a critical challenge in mitigating climate change. Circulating Fluidized Bed (CFB) boilers offer fuel flexibility, enabling the integration of more environmentally friendly biogenic or waste-derived fuels such as Solid Recovered Fuel (SRF). However, replacing conventional fuels with high-volatile alternatives poses challenges related to combustion stability and efficiency. Oxygen Carrier Aided Combustion (OCAC) with ilmenite as a bed material enhances combustion efficiency and reduces emissions by facilitating oxygen transport within the fluidized bed. Additionally, oxyfuel combustion offers a promising pathway for carbon capture but is hindered by high oxygen demand. This study combines OCAC and oxyfuel combustion, presenting the first autothermal Oxyfuel-OCAC (Oxy-OCAC) experiments conducted at the 1 MW th scale, utilizing 100% SRF as feedstock. The pilot plant enables oxyfuel operation with wet flue gas recirculation and pure oxygen supply, allowing a controlled transition from air-fired to oxyfuel conditions in 16 minutes. Differential pressure profiles revealed increasing particle loads in the free board zone with increasing inlet oxygen concentration, leading to a more uniform temperature distribution throughout the CFB reactor. Flue gas analysis confirmed that Oxy-OCAC improves combustion stability compared to oxyfuel combustion with sand as bed material, enhancing oxygen distribution within the reactor. These findings demonstrate that Oxy-OCAC is a promising approach to increasing the efficiency and economic viability of oxyfuel combustion in CFB systems. The combination of ilmenite with SRF in an oxyfuel environment enhances CO₂ capture potential while ensuring stable reactor operation, supporting sustainable energy production.

Source: Carbon Capture Science & Technology

DOI: 10.1016/j.ccst.2025.100436

Authors: Alexander Kuhn, Christoph Graf, Jochen Ströhle, Bernd Epple

Institution: Technische Universität Darmstadt

Language: English

Topic: Chemical Looping and Thermochemical Processes

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Responsible consumption and production, Climate action, Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $2,000