Ionic liquids and deep eutectic solvents for biodiesel synthesis: a review

Abstract

During the past decade, ionic liquids (ILs) have gained tremendous attention in nearly every branch of the chemical and physical sciences as designer (task‐driven) and budding ‘green’ solvent alternatives to conventional volatile organics. In particular, with a more in‐depth understanding of their physicochemical properties, the active exploration of ILs as alternative solvents and/or catalysts in the chemical or enzymatic (biocatalytic) production of biodiesel has gained momentum. Most excitingly, very recent developments in the science of deep eutectic solvents (DESs) have initiated potentially more cost‐effective approaches to biodiesel synthesis. At this stage, there is sufficient research completed to provide an important opportunity to stand back and assess the progress in the field, critically examining the strengths and limitations for IL and DES technology in biodiesel synthesis. No such comprehensive evaluation exists. This work, therefore, seeks to bridge this gap by systematically reviewing the reported methods for biodiesel production which make use of ILs, either as (co)solvent components or catalysts, highlighting existing problems and limitations, with an emphasis placed on the future research required to bypass the hurdles to employing ILs in commercial biodiesel production. Copyright © 2012 Society of Chemical Industry

A comprehensive review on biodiesel purification and upgrading

“…Ionic liquids (ILs) have attracted a great deal of attention as green solvents owning to their non-flammable, non-volatile, and reusable properties making them excellent and safer choices for the extraction processes (Han and Row, 2010;Zhao and Baker, 2013). Many different organic, inorganic, and organometallic materials can be easily and efficiently dissolved in ILs; however, their high costs often limit their applications (Shahbaz et al, 2010).…”

Measurement and PC-SAFT modeling of solid-liquid equilibrium of deep eutectic solvents of quaternary ammonium chlorides and carboxylic acids

“…The [Ch]Cl:urea mixture (1:2 mol), for example, was used in the Perkin condensation of cinnamic acid [9], reduction of epoxides [10] or in an electrophilic substitution of quinone derivatives [11]. Other applications are the incorporation of metal ions in solution for metal deposition and electro polishing [3], metal extraction [12], conversion of lignocellulosic biomass [13], gas separations [14], extraction of glycerol from biodiesel [15], extraction media for azeotropic mixtures [16], fuel purification [17], potential drug vehicles [18], or in the preparation of nanomaterials [19].…”

Combi-protein coated microcrystals of lipases for production of biodiesel from oil from spent coffee grounds

“…The global shortage of fossil fuels and environmental concerns has sustained the interest in biodiesel production [19][20][21][22][23][24][25][26][27][28][29][30]. Biodiesel is a mixture of esters of long chain fatty acids and short chain monohydric alcohols (MeOH or EtOH).…”

“…Biodiesel can be obtained from plant oils which constitute renewable resources. Biodiesel is biodegradable and its use (in place of diesel) leads to lower engine exhaust emissions of particulate matter and green house gases such as CO, CO 2 and SO x [24,30].…”