Polyester conversion by homogeneous catalysis for separating and recycling ammonia from biogas

Area of Science:

• Environmental Science
• Chemical Engineering
• Materials Science

Background:

• Biogas, a renewable energy source, contains ammonia (NH3), a precursor to harmful nitrogen oxides (NOx) and particulate matter (PM2.5).
• Effective ammonia removal is crucial for mitigating ecological and human health risks associated with biogas utilization.

Purpose of the Study:

• To investigate the recycling of waste ammonia from biogas using optimized polyester as a sorbent material.
• To enhance ammonia adsorption capacity and explore its potential as a raw material for nitrogen fertilizer.

Main Methods:

• Optimized polyester as a sorbent material for ammonia capture.
• Homogeneous catalysis to modify polyester and increase adsorption sites.
• Structural characterization, functional group analysis, and kinetic analysis to understand adsorption mechanisms.
• Selective adsorption and regeneration experiments to evaluate separation efficiency and reusability.

Main Results:

• Optimized polyester exhibited a significant increase in ammonia adsorption capacity, from 0.56 mg·g⁻¹ to 84.07 mg·g⁻¹.
• Chemical adsorption was identified as the dominant mechanism for ammonia adsorption onto the modified polyester.
• Efficient separation of ammonia from biogas was achieved with good regeneration performance of the polyester sorbent.

Conclusions:

• Recycling waste ammonia from biogas using optimized polyester is an effective strategy.
• This approach offers a viable method for producing nitrogen fertilizer while mitigating biogas-related environmental and health concerns.