Sustainable ammonia and amines from chitin

Area of Science:

• Biomass Conversion
• Catalysis
• Sustainable Chemistry

Background:

• The Haber-Bosch process is the primary method for ammonia production but is energy-intensive.
• Extracting nitrogen compounds from natural biomass remains an under-exploited area for sustainable chemical synthesis.

Purpose of the Study:

• To develop a catalytic strategy for direct amine and ammonia production from chitin.
• To explore the potential of utilizing waste biomass, such as shrimp shells, for nitrogen compound synthesis.

Main Methods:

• A synergistic catalytic system combining phosphoric acid and modified Ruthenium (Ru)-based catalysts was employed.
• Chitin underwent cleavage of ether bonds and protection of amino groups facilitated by phosphoric acid.
• Controlled adjustment of the Ru⁰/Ruⁿ⁺ ratio enabled selective hydrogenation, deoxygenation, and amination.

Main Results:

• High utilization of nitrogen atoms from chitin, reaching up to 95%.
• The process yielded 21% amines and 74% ammonium.
• The catalytic strategy proved effective for waste shrimp shells, demonstrating applicability to real-world biomass.

Conclusions:

• This study demonstrates an efficient method for producing valuable nitrogen-containing compounds from abundant biopolymers like chitin.
• The developed catalytic process offers a sustainable alternative for amine and ammonia production, utilizing waste resources.