Sanduni Geeganage

University of Canterbury, New Zealand

Title: Valorization of Apricot Kernel Waste for Sustainable Benzaldehyde Production with Integrated Cyanide Treatment

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Biography

Sanduni Geeganage is a third-year PhD student at the School of Product Design, University of Canterbury, New Zealand, working under the supervision of Prof. Conan Fee and Dr. Pram Abhayawardhana. Her research focuses on the sustainable extraction of benzaldehyde from apricot kernels with the simultaneous treatment of toxic hydrogen cyanide gas. Her aim is to develop scalable, safe, and sustainable processes for natural benzaldehyde extraction from stone fruit waste, with an emphasis on improving process efficiency while minimizing environmental and safety risks.

Abstract

Apricot kernels are an abundant and underutilized byproduct of the fruit processing industry, representing both a waste management challenge and an opportunity for resource recovery. This study explores a novel waste-to-value strategy for recycling apricot kernel waste into benzaldehyde, a high-value aromatic compound widely used in the flavour and fragrance industry. Benzaldehyde is naturally produced through the enzymatic hydrolysis of amygdalin present in apricot kernels; however, the simultaneous release of toxic hydrogen cyanide (HCN) limits the safe and scalable implementation of this process. To address these challenges, an integrated extraction and off-gas treatment approach was developed, combining ultrasound-assisted hydrodistillation (UAHD) with catalytic oxidation of HCN in a bubble column reactor. Hydrogen peroxide (H?O?) and copper sulfate (CuSO?) were employed as the oxidant and catalyst, respectively, enabling effective detoxification of cyanide-containing off-gas during extraction. A Taguchi design of experiments was applied to optimize key extraction parameters, including liquid-to-solid ratio, sonication time, ultrasound amplitude, and hydrodistillation time. Under optimal conditions, UAHD resulted in a 2.07-fold increase in benzaldehyde yield compared to conventional hydrodistillation, while reducing energy consumption and carbon footprint by 49.3% and 49.1%, respectively. The influence of gas flow rate, H?O? concentration, and CuSO? dosage on HCN oxidation was further evaluated to establish reaction kinetics and optimize the integrated system for efficient extraction with off-gas treatment. Overall, this work demonstrates a novel advance in recycling and waste management by converting stone fruit processing waste into a valuable product while simultaneously eliminating hazardous emissions. The proposed approach supports sustainable waste minimization, pollution control, and circular resource utilization within agro-industrial systems.