Extraction of rubber seed oil as a feedstock for epoxidation process via mixed solvent

• Published in: BIOMASS CONVERSION AND BIOREFINERY
• Main Authors: Hambali, Norhafini; Jalil, Mohd Jumain; Azmi, Intan Suhada; Shamjuddin, Amnani; Alias, Nur Hashimah
• Format: Article; Early Access
• Language: English
• Published: SPRINGER HEIDELBERG 2025
• Subjects: Energy & Fuels; Engineering
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001415151600001
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-025-06552-2

Epoxidized vegetable oils and by-products of their conversions are commonly used in many industrial applications. The widespread use of edible oil as the raw material for the epoxidation process raises issues regarding food safety. Rubber seed oil (RSO), a non-edible oil with a high unsaturation percentage, has the potential to replace edible oils as a raw material for the epoxidation process. Because of its remarkable efficiency, RSO extraction now employs a single solvent, n-hexane. This study mixed n-hexane, a non-polar solvent, with polar solvents to fully extract a wide range of lipids contained in rubber seeds while increasing extraction efficiency. The combination of n-hexane and acetone resulted in the maximum oil yield of 67.31% after 6 h of extraction with a kernel size of 0.25 mm and a solid-to-solvent ratio of 0.05. The number of fatty acid compositions detected in the rubber seed oil was greater than that of commercial rubber seed oil, demonstrating that the combination of polar and non-polar solvents was effective in extracting a wide range of lipids. Fatty acid composition analysis revealed the presence of gamma-linolenic acid (41.6%), linolelaidic acid (21.7%), linolenic acid (19.1%), palmitic acid (8.7%), and elaidic acid (7.8%) among the fatty acids. Its high unsaturation degree (82.4%) and physicochemical qualities make it a viable feedstock for epoxidized rubber seed oil (ERSO). The extracted RSO was epoxidized in situ using formic acid and hydrogen peroxide, with zeolite ZSM-5 acting as a catalyst. At 30 min, the greatest ERSO yield was 21.6%. These results showed that the co-solvent system increased extraction efficiency and the ability to synthesize ERSO from rubber seed oil.