No abstract

The increasing global demands for fossil fuels have resulted in the release of large quantity of pollutants and reduction of the available resources. Owing to this fact, alternatives to fossil fuels, like biodiesel, are essential for the survival of the existing resources and the decrease of environmental contamination. In the current study, the technical assessment of five continuous biodiesel production processes was designed and simulated with the Aspen Plus v8.6 software. In order to convert virgin vegetable oil (VVO) as well as waste cooking oil (WCO) to biodiesel, alkali‐catalyzed and acid‐catalyzed processes were utilized in the first three processes. In the fourth and fifth processes, the two‐step supercritical methanol method (noncatalytic) and the acid‐catalyzed process were adopted by hexane extraction to transform the WCO to biodiesel. According to the technical assessment, the two‐step supercritical methanol process has the lowest number of operating units; however, it has the lowest purity of FAME (98.47%). The highest purity of glycerol (99.98%) and FAME (99.7%) belong to Processes 3 and 1, respectively. As a result, the homogeneous acid catalytic process of WCO and the two‐step supercritical methanol process are the best choices in terms of technical evaluation among all the examined processes.

Introduction: By substituting conventional fossil fuels, biofuel can emerge as a potential sustainable energy source with favorable environmental outcomes. Biodiesel, in particular, is increasingly attracting attention due to its high potential to increase the consumption of biofuel and contributing to sustainable development. Experimental studies have revealed that biodiesel can play a considerable role of biodiesel in improving petroleum-based characteristics. Materials and Methods: Physicochemical properties of pure biodiesel produced through esterification and transesterification, petroleum diesel, and biodiesel-diesel blends were experimentally measured. Ninety percent of the filtered and dried waste cooking oil (WCO) was converted to biodiesel, and it was shown that cetane index, flash point, and fire point increased by applying B10 (10% biodiesel + 90% petrodiesel) instead of petrodiesel. Results: B10 exhibited an adequate depression in pour point and cloud point by 6°C and 3°C at low temperature, respectively. Also, in this study, an economical study and a sensitivity analysis of a biodiesel production plant from WCO with a capacity of 90 tons per day was carried out, using COMFAR III software. The highest proportion of operating cost belonged to WCO (75%) followed by methanol (10%) and machinery, service, and maintenance expense (5%). Conclusion: Biodiesel showed a positive influence on petrodiesel characteristics, in which the desired green fuel contributed to save the environment. Eventually, economic analysis provides the possibility of running a plant in Iran as a sustainable solution to energy issues.