ORIGINAL ARTICLE Multivariable Analysis and Optimization of Biodiesel Production from Waste Cooking Oil Mohammad Ali Zahed 1 & Zahra Zakeralhosseini 2 & Leila Mohajeri 3 & Gholamreza Nabi Bidhendi 4 & Saba Mesgari 1 Received: 5 January 2018 /Accepted: 13 April 2018 # Springer International Publishing AG, part of Springer Nature 2018 Abstract The aim of this paper was to study biodiesel production from waste cooking oil using a transesterification method. Optimization was achieved by changing process variables, including the oil:alcohol molar ratio and reaction temperature, to maximize biodiesel yield. Optimum variables were identified using Central Composite Face-Centered Design (CCFD) and Response Surface Methodology (RSM). Furthermore, the synergistic and antagonistic effects among process parameters were analyzed. The optimum temperature for the production of biodiesel was identified at 62.8 °C, and the optimum oil:alcohol ratio was 4.3; the combination of these parameters resulted in the highest theoretical efficiency of 96.08% and desirability of 0.608. After evaluating the experimentally produced biodiesel, the study revealed that waste cooking oil can be used as a potential raw material for the production of biofuel. Keywords Biodiesel . Biofuel . Waste cooking oil . Response surface methodology 1 Introduction With increasing concern for world energy and global warming crises, many researches are focusing on alternative energy resources (Liu et al. 2010; Ullah et al. 2015). Bio-fuel is an attractive alternative to petroleum-based fuels due to characteristics that are similar to diesel Environ. Process. https://doi.org/10.1007/s40710-018-0299-2 * Mohammad Ali Zahed zahed51@yahoo.com 1 Faculty of Biological Sciences, Kharazmi University, Tehran, Iran 2 Department of Energy System Engineering, University of Tehran, Alborz Campus, Karaj, Iran 3 The Society of Petroleum Engineers (SPE), Iran’ s Section, Tehran, Iran 4 Graduate Faculty of Environment, University of Tehran, P.O. Box 14155-6135, Tehran, Iran