Continuous Integrated Process of Biodiesel Production and Purification—The End of the Conventional Two-Stage Batch Process?

Abstract

In this research, optimization of the integrated biodiesel production process composed of transesterification of edible sunflower oil, catalyzed by commercial lipase, with simultaneous extraction of glycerol from the reaction mixture was performed. Deep eutectic solvents (DESs) were used in this integrated process as the reaction and extraction media. For two systems, choline chloride:glycerol (ChCl:Gly) and choline chloride:ethylene glycol (ChCl:EG), respectively, the optimal water content, mass ratio of the phase containing the mixture of reactants (oil and methanol) with an enzyme and a DES phase (mass ratio of phases), and the molar ratio of deep eutectic solvent constituents were determined using response surface methodology (RSM). Experiments performed with ChCl:Gly resulted in a higher biodiesel yield and higher glycerol extraction efficiency, namely, a mass ratio of phases of 1:1, a mass fraction of water of 6.6%, and a molar ratio of the ChCl:Gly of 1:3.5 were determined to be the optimal process conditions. When the reaction was performed in a batch reactor under the optimal conditions, the process resulted in a 43.54 ± 0.2% yield and 99.54 ± 0.19% glycerol extraction efficiency (t = 2 h). Unfortunately, the free glycerol content was higher than the one defined by international standards (wG > 0.02%); therefore, the process was performed in a microsystem to enhance the mass transfer. Gaining the same yield and free glycerol content below the standards (wG = 0.0019 ± 0.003%), the microsystem proved to be a good direction for future process optimization.

Synthesis of Hydroxylated Stilbenes in a Batch and Flow Reactor: An Overview

“…In coil reactor, a mixing unit is required, which is usually an additional Y-, Ψ-, T-shaped, or other connector that is also made of inert material such as PTFE. [19,73,75] Since heterogeneous catalysis is often required in flow chemical reactions, packed bed reactors with columns or cartridges including filter units are used. Columns are mostly made of glass, stainless steel, or polymers and are filled with solid catalyst through which the reaction mixture is pumped.…”

“…For this reason, they are the most commonly used type of reactor, despite the somewhat lower surface‐to‐volume ratio compared to chip reactors. In coil reactor, a mixing unit is required, which is usually an additional Y‐, Ψ‐, T‐shaped, or other connector that is also made of inert material such as PTFE [19,73,75] . Since heterogeneous catalysis is often required in flow chemical reactions, packed bed reactors with columns or cartridges including filter units are used.…”

Advances in Catalytic Technologies for Biodiesel Fuel Synthesis

“…Given that, in the production of biodiesel, the purification of the reaction product from soaps and glycerol consumes a large amount of water and generates almost 10 times more wastewater than the resulting biodiesel, Bačic et al [5] proposes the application of an integrated biodiesel production process for transesterification of edible sunflower oil, catalysed by commercial lipase, with simultaneous extraction of glycerol from the reaction mixture. Choline chloride and glycerol and choline chloride and ethylene glycol mixtures can be used as glycerol extraction agents.…”

Continuous Purification of Biodiesel with Deep Eutectic Solvent in a Laboratory Karr Column

“…Continuous glycerol extraction processes with DESs found in the literature include integrated production and purification of sunflower oil biodiesel in a microreactor [7,8] and continuous purification of sunflower oil [9] and waste coffee ground oil biodiesel [10] in a Karr column.…”