A novel ionic liquid, chlorocholine hydroxide (CCH), was first synthesized and then stabilized on boehmite nanoparticles (BNPs-CCH). Variables such as weight percentage of catalyst, methanol to oil molar ratio and reaction time were evaluated to study the catalyst efficiency in the production of bio-diesel from soybean oil and methanol. Results showed that the biodiesel yield maximum was obtained in 95.2% for optimal conditions of 11:1, 4.13 wt, 60 degrees C and 4.4 h for the molar ratio of methanol to oil, weight percentage of catalyst, temperature and reaction time, respectively. In addition, the prepared nano catalyst was applied 5 times under optimal conditions in order to evaluate the catalyst efficiency. According to the results it still indicated as high efficiency as in the production of biodiesel. Therefore, the strength and durability of the resultant nanocatalyst were confirmed in this research. (C) 2019 Elsevier Ltd. All rights reserved.