Optimization of rapid microwave-assisted extraction and epoxidation of D-limonene from waste orange peelsJayavignesan Visvalingam, Yee Ho Chai, Shafirah Samsuri, and Mohd Hizami Mohd Yusoff HICoE-Centre for Biofuel and Biochemical Research, Institute of Sustainable Energy and Resources, Department of Chemical Engineering, Universiti Teknologi PETRONAS, Perak, Malaysia
Received: 21 August 2025 Accepted: 19 October 2025 Abstract: This study explores the implementation of microwave-assisted extraction (MAE) to extract naturally occurring d-limonene from waste orange peels in the absence of organic solvents. The extraction process was optimized using diced orange peels at 1300 W microwave power and a 1:3 sample-to-water ratio with 500 g of biomass, yielding approximately 90% of d-limonene from the essential oil extract. In conjunction, the d-limonene extract is then subjected to an epoxidation reaction with lipase B from Candida antarctica (CalB), immobilized on Immobead 150, a recombinant of yeast as a green catalyst, followed by the incorporation of microwave irradiation to produce 1,2-limonene oxide. The epoxidation process was optimized to achieve high-purity 1,2-limonene oxide at a 98% conversion rate with 40 mM of extracted d-limonene, 70 mM of octanoic acid, a temperature of 50 °C, 5% catalyst loading, a reaction time of 30 min, and 250 mM of hydrogen peroxide (35% aqueous solution) while 20 ml of toluene was used as a solvent. A detailed qualitative and quantitative analysis was also conducted to support the reported purity of the desired products while a comparative analysis highlights the enhanced performance of the proposed process as a promising green alternative for industrial bioproducts derived from citrus waste. Keywords: d-Limonene; Orange peel waste; Waste-to-wealth; Microwave; Sustainable; Green catalyst Full paper is available at www.springerlink.com. DOI: 10.1007/s11696-025-04469-8
Chemical Papers 80 (2) 1535–1551 (2026) |
Saturday, April 25, 2026 
|
|||
© 2026 Chemical Papers |
|
|||
