title: Biodiesel from Citrullus colocynthis oil: sulfonic-ionic liquid-catalyzed esterification of a two-step process.
abstract: Biodiesel was prepared from Citrullus colocynthis oil (CCO) via a two-step process. The first esterification step was explored in two ionic liquids (ILs) with 1,3-disulfonic acid imidazolium hydrogen sulfate (DSIMHSO4) and 3-methyl-1-sulfonic acid imidazolium hydrogen sulfate (MSIMHSO4). Both ILs appeared to be good candidates to replace hazardous acidic catalyst due to their exceptional properties. However, the two sulfonic chains existing in DSIMHSO4 were found to increase the acidity to the IL than the single sulfonic chain in MSIMHSO4. Based on the results, 3.6 wt% of DSIMHSO4, methanol/CCO molar ratio of 12 : 1, and 150 °C offered a final FFA conversion of 95.4% within 105 min. A 98.2% was produced via second KOH-catalyzed step in 1.0%, 6 : 1 molar ratio, 600 rpm, and 60 °C for 50 min. This new two-step catalyzed process could solve the corrosion and environmental problems associated with the current acidic catalysts.
authors.affiliation: Department of Chemical and Materials Engineering, King Abdulaziz University, P.O. Box 344, Rabigh, Saudi Arabia.
authors.forename: Yasir
authors.initials: Y
authors.lastname: Ali Elsheikh
authors.affiliation: Department of Chemical and Materials Engineering, King Abdulaziz University, P.O. Box 344, Rabigh, Saudi Arabia.
authors.forename: Faheem
authors.initials: F
authors.lastname: Hassan Akhtar
mesh_terms: D056804:Biofuels; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D065986:Citrullus colocynthis / Q000737:chemistry*; D004951:Esterification; D052578:Ionic Liquids; D010938:Plant Oils / Q000737:chemistry*
chemical_list: D056804:Biofuels; D052578:Ionic Liquids; D010938:Plant Oils