Novel process for biodiesel by reactive absorption

Process integration and intensification is increasingly applied also in the biodiesel production, as shown by recent research papers. This study takes previous work on reactive separation processes for biodiesel production to a new level by proposing an innovative technology based on reactive absorption using solid acid catalysts. This is a major step forward since reactive absorption offers significant benefits over reactive distillation, such as: reduced capital investment and operating costs due to the absence of the reboiler and condenser, higher conversion and selectivity as no products are recycled in the form of reflux or boil-up vapors, as well as no occurrence of thermal degradation of the products due to a lower temperature profile in the column. Rigorous simulations embedding experimental results were performed in AspenTech AspenONE engineering suite to design this novel reactive absorption process and evaluate the technical and economical feasibility. The main results are given for a plant producing 10 ktpy biodiesel from waste vegetable oil with high free fatty acids content, using solid acids as green catalysts. This innovative process eliminates all conventional catalyst-related operations, and efficiently uses the raw materials and the reactor volume in an integrated setup that allows significant savings in CapEx and OpEx of the plant.