Biodegradable base stock oils obtained from ricinoleic acid using C8 alcohols and process integration into a biodiesel industry

The strategies for sustainability and competitiveness of the biodiesel industry may be improved by adding value through co-products, especially for novel biodegradable products from non-edible vegetable oils. In this study, the chemical modifications of ricinoleic acid obtained from castor oil were performed to obtain biodegradable base stock oils. The chemical route was carried out using C8 alcohols (octanol or 2-ethyl-hexanol) in esterification and oxirane rings opening reactions under commercial catalysts. All chemical modifications were monitored by nuclear magnetic resonance (1H NMR) and physicochemical properties of products. The biodegradability of synthesized samples was determined using a bio-kinetic model. The results indicated that the bio-based samples from 2-ethyl-hexanol had the lowest pour point (− 57 °C) and the highest oxidative stability. The biodegradability tests showed that all synthesized samples have half-life around 20–60 days. From these results, this studied route using ricinoleic acid and C8 alcohols was considered to be applied to an existing biodiesel industry. Finally, a multi-purpose flexible industrial configuration was proposed to be able to obtain both biodiesel and the biodegradable base stocks for lubricant oils.