The College of Engineering at the University of Baghdad witnessed the public defense of the master’s thesis by Ohwod Qassim Mohammed in the Department of Chemical Engineering. Her thesis, titled “Batch Reactor Coupled with Continuous Microwave Tubular Reactor Effected on the Production of Biodiesel” was presented on Monday, February 09, 2026, in Professor Mahmoud Omar Hall within the Department of Chemical Engineering, under the supervision of Asst. Prof. Dr. Atheer Mohammed Al-Yaqoobi
Biodiesel is regarded as one of the most valuable renewable fuels, but its widespread usage is still limited due to the high cost of raw materials and the complexity of the production process. This has led to the development of modern technologies aimed at reducing manufacturing costs and improving process efficiency. One promising approach to enhancing the economic feasibility and environmental sustainability of biodiesel production is the utilization of byproducts and waste materials.
This research compares the production of biodiesel from waste cooking oil (WCO) using three transesterification systems: conventional Batch heating, Microwave-Assisted Batch, and continuous-flow microwave heating, employing a calcium oxide (CaO) nano-catalyst derived by Extracting fallen willow leaves via Calcination. The catalyst was characterized using XRD, FTIR, SEM-EDX, BET, XRF, and EDS analyses. The produced biodiesel was analyzed by FT-IR and GC, and its properties were compared with ASTM D6751 and EN 14214 standards.
Under optimal conditions (70 wt.% methanol-to-oil ratio, 3 wt.% catalyst, 65°C, 1.5 h, and 700 rpm), the conventional system achieved a maximum yield of 93.852%, following pseudo-first-order kinetics with an activation energy of 49.48 kJ/mol. The catalyst remained stable up to the fifth reuse cycle, maintaining a yield of 79.9%. In the batch microwave system, a maximum yield of 96.313% was obtained at 65°C within 20 minutes using 3 wt.% catalyst, 10% microwave power, and a 70 wt.% methanol-to-oil ratio, with an activation energy of 24.266 kJ/mol. In the continuous-flow microwave system, a maximum yield of 93.43% was achieved in only 5 minutes at 20% microwave power (800 W), 3 wt.% catalyst, and 70 wt.% methanol-to-oil ratio, with an activation energy of 15 kJ/mol.
Energy analysis showed that the conventional system consumed the highest energy (0.945 kWh), while the batch microwave system consumed the lowest (0.026666 kWh), followed by the continuous system (0.03433 kWh). The results demonstrate that CaO nano-catalysts derived from biomass waste combined with microwave heating systems provide an efficient and environmentally friendly approach for producing high-quality biodiesel with reduced energy consumption, supporting the principles of green chemistry.
