Ash Interaction with Two Cu-Based Magnetic Oxygen Carriers during Biomass Combustion by the Chemical Looping with...

Area of Science:

• Chemical engineering
• Environmental science
• Combustion technology

Background:

• Chemical-looping combustion (CLC) is a key technology for carbon capture and climate change mitigation.
• Biomass combustion via CLC offers potential for negative CO2 emissions.
• Biomass ash interactions with oxygen carriers pose challenges for CLC system longevity.

Purpose of the Study:

• To investigate the interaction between biomass ash and novel oxygen carriers (Cu30MnFekao7.5 and Cu30MnFe).
• To assess the impact of these interactions on oxygen carrier performance during combustion.

Main Methods:

• Combustion experiments were conducted in a 1.5 kWth continuous unit using biomass feedstock.
• Inductively coupled plasma (ICP) and scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) were used to analyze oxygen carriers post-combustion.

Main Results:

• Both oxygen carriers achieved 100% combustion efficiency and 95% CO2 capture efficiency at 900 °C.
• No significant interaction was observed between copper in the carriers and ash components.
• Accumulation of potassium and magnesium was detected in the Cu30MnFekao7.5 carrier after operation.
• No agglomeration or fluidization issues were encountered with either carrier.

Conclusions:

• The tested oxygen carriers demonstrate high efficiency for CO2 capture from biomass.
• While generally robust, specific carriers may accumulate elements like potassium and magnesium from biomass ash.
• Further research into ash-carrier interactions is crucial for optimizing long-term CLC performance with biomass.