Efficient transformation of starch food wastes into bio-based levulinate products over earth-abundant aluminum salts: Performances and economics

This study presented the first example on the transformation of starch-rich food wastes (e.g. rice, potato, bread) into oxygenated chemicals, namely methyl levulinate (ML), over the cheap and earth-abundant metal salt catalysts. A variety of metal salts were systematically tested and Al₂(SO₄)₃ exhibited the best catalytic reactivity for the alcoholysis reaction, offering a 51.5 mol% yield of ML in the conversion of rice waste powder in the methanol/water mixture solvent. A series of different food wastes were successfully converted to ML with different product yields (17.3–51.5 mol%). The reaction parameters were systematically optimized to reveal their influences on the product yields. The catalyst recycling procedure was proposed to recycle and reuse the reagents involved in the system. Finally, a preliminary economic analysis of the system was also included.