Production of Sustainable Biochemicals by Means of Esterification Reaction and Heterogeneous Acid Catalysts

Rosa Vitiello,Rosa Turco,Martino Di Serio,Antonio Buonerba,Alfonso Grassi,Riccardo Tesser,Francesco Taddeo,Vincenzo Russo

doi:10.3390/chemengineering5030046

Abstract

In recent years, the use of renewable raw materials for the production of chemicals has been the subject of different studies. In particular, the interest of the present study was the use of oleins, mixtures of free fatty acids (FFAs), and oleic acid to produce bio-based components for lubricants formulations and the investigation of the performance of a styrene-divinylbenzene acid resin (sPSB-SA) in the esterification reaction of fatty acids. This resin has shown good activity as a heterogeneous catalyst and high stability at elevated temperatures (180 °C). It was tested in the esterification reaction of oleic acid with 1,3-propanediol and of oleic acid with glycerol. In particular, the esterification reactions were performed in a steel stirred batch reactor and a PBR loop reactor. Tests were conducted varying the reaction conditions, such as alcohol type, temperature, reaction time, and catalysts, both homogeneous and heterogeneous ones. From the obtained results, acid resin (both in reticulated and not-reticulated form) showed high activity in esterification reaction of oleic acid with 1,3-propanediol and of oleic acid with glycerol and good resistance to the deactivation; thus, they can be considered promising candidates for future applications in continuous devices. Viscosity tests were performed, underlining the good properties of the obtained products as lubricant bases.

Highlights

Published: 7 August 2021A lubricant is a substance that reduces friction, providing a protective film between two moving surfaces; lubrication occurs when two surfaces in motion are separated by a lubricant film.A good lubricant shows characteristics such as high viscosity index, high boiling point, thermal stability, low freezing point, corrosion prevention capability, and high resistance to oxidation [1].The demand for lubricants in the world was around 35 million tons per year since1991 with an estimated annual growth of 0.8% until 2007 and about 2% since 2012 [1].Nowadays, most of the used lubricants are still based on mineral oil, several improvements in lubricant technologies have led to the development of environmentally friendly products in many applications
Most of the used lubricants are still based on mineral oil, several improvements in lubricant technologies have led to the development of environmentally friendly products in many applications
The replacement of petroleum-based oils with biodegradable products, within lubricants formulation, is the principal way to reduce the negative effects on the ecosystem caused by the intensive use of lubricants [2]

Summary

Introduction

Published: 7 August 2021A lubricant is a substance that reduces friction, providing a protective film between two moving surfaces; lubrication occurs when two surfaces in motion are separated by a lubricant film.A good lubricant shows characteristics such as high viscosity index, high boiling point, thermal stability, low freezing point, corrosion prevention capability, and high resistance to oxidation [1].The demand for lubricants in the world was around 35 million tons per year since1991 with an estimated annual growth of 0.8% until 2007 and about 2% since 2012 [1].Nowadays, most of the used lubricants are still based on mineral oil, several improvements in lubricant technologies have led to the development of environmentally friendly products in many applications. The replacement of petroleum-based oils with biodegradable products, within lubricants formulation, is the principal way to reduce the negative effects on the ecosystem caused by the intensive use of lubricants [2]. Due to their volatility, petroleum-based lubricants can contaminate the soil and pollute the air, representing a danger for the residents in these areas. Hazardous effects on the respiratory system can be caused by contact with petroleum-based lubricants [3,4,5,6,7,8].

Methods

Results

Conclusion