Production of Biofuel Additives Using Catalytic Bioglycerol Etherification: Kinetic Modelling and Reactive Distillation Design

Abstract

Glycerol is an unavoidable by-product of the biodiesel production process. The conversion of glycerol into valuable biofuel additives is essential in the fuel industry. The goal of this work is to develop a reactive distillation-based process for the production of biofuel additives by bio-glycerol etherification. In this study, a kinetic model using a lumping approach for glycerol etherification with tert-butyl alcohol (TBA) over Sn (II) phosphomolybdate (Sn1.5PMo12O40) catalyst was developed. Aspen Plus was used to validate the kinetic model by simulating the glycerol etherification with TBA in a batch reactor. The model predictions were in good agreement with the experimental data. A reactive distillation-based process to produce glycerol ethers was developed, and heat integration was conducted to reduce energy consumption. The energy requirements of the integrated process and the CO2 emissions were decreased by 17% and 14%, respectively. An economic evaluation was performed to study the profitability of the process for an annual capacity of 33,000 metric tons of glycerol ethers. It was found that the process is economically attractive, with a return on investment of 29.40% and a payback period of 2.2 years. The reactive distillation-based process is green and promising for producing biofuel additives that are sustainable and environmentally friendly.