TY - JOUR AB - This study investigates the effect of direct sonication in conversion of waste cooking oil into biodiesel. Waste cooking oils may cause environmental hazards if not disposed properly. However, waste cooking oils can serve as low-cost feedstock for biodiesel production. Ultrasonics, a non-conventional process technique, was applied to directly convert waste cooking oil into biodiesel in a single step. Ultrasonics transesterify waste cooking oils very efficiently due to increased mass/heat transfer phenomena and specific thermal/athermal effects at molecular levels. Thus, energy and chemical consumption in the overall process is greatly reduced compared to conventional biodiesel processes. Specific to this research, thermal effects of ultrasonics in transesterification reaction without external conventional heating along with effects of different ultrasonic, energy intensities and energy density are reported. Optimization of process parameters such as methanol to oil ratio, catalyst concentration and reaction time are also presented. It was observed that small reactor design such as plug-flow or contact-type reactor design may improve overall ultrasonic utilization in the transesterification reaction due to increased energy density and ultrasonic intensity. (C) 2013 Elsevier Ltd. All rights reserved. AD - Mississippi State Univ, Dept Civil & Environm Engn, Mississippi State, MS 39762 USA AN - WOS:000321724000016 AU - Gude, V. G. AU - Grant, G. E. DA - Sep DO - 10.1016/j.apenergy.2013.04.002 J2 - Appl Energ KW - biodiesel LA - English N1 - Sp. Iss. SI PY - 2013 SN - 0306-2619 SP - 135-144 ST - Biodiesel from waste cooking oils via direct sonication T2 - Applied Energy TI - Biodiesel from waste cooking oils via direct sonication UR - ://WOS:000321724000016 VL - 109 ID - 8737 ER -