Highly efficient Brønsted acidic ionic liquid-based catalysts for biodiesel synthesis from vegetable oils

Advances in Enzyme and Ionic Liquid Immobilization for Enhanced in MOFs for Biodiesel Production

Biodiesel is a promising candidate for sustainable and renewable energy and extensive research is being conducted worldwide to optimize its production process. The employed catalyst is an important parameter in biodiesel production. Metal-organic frameworks (MOFs), which are a set of highly porous materials comprising coordinated bonds between metals and organic ligands, have recently been proposed as catalysts. MOFs exhibit high tunability, possess high crystallinity and surface area, and their order can vary from the atomic to the microscale level. However, their catalytic sites are confined inside their porous structure, limiting their accessibility for biodiesel production. Modification of MOF structure by immobilizing enzymes or ionic liquids (ILs) could be a solution to this challenge and can lead to better performance and provide catalytic systems with higher activities. This review compiles the recent advances in catalytic transesterification for biodiesel production using enzymes or ILs. The available literature clearly indicates that MOFs are the most suitable immobilization supports, leading to higher biodiesel production without affecting the catalytic activity while increasing the catalyst stability and reusability in several cycles.

Techno-Economic Performance of Different Technological Based Bio-Refineries for Biofuel Production

There are different technologies for biodiesel production, each having its benefits and drawbacks depending on the type of feedstock and catalyst used. In this study, the techno-economic performances of four catalyst technologies were investigated. The catalysts were bulk calcium oxide (CaO), enzyme, nano-calcium oxide, and ionic liquid. The study was mainly based on process simulations designed using Aspen Plus and SuperPro software. The quantity and quality of biodiesel and glycerol, as well as the amount of biodiesel per amount of feedstock, were the parameters to evaluate technical performances. The parameters for economic performances were total investment cost, unit production cost, net present value (NPV), internal return rate (IRR), and return over investment (ROI). Technically, all the studied options provided fuel quality biodiesel and high purity glycerol. However, under the assumed market scenario, the process using bulk CaO catalyst was more economically feasible and tolerable to the change in market values of major inputs and outputs. On the contrary, the enzyme catalyst option was very expensive and economically infeasible for all considered ranges of cost of feedstock and product. The result of this study could be used as a basis to do detail estimates for the practical implementation of the efficient process.

Efficient confinement of ionic liquids in MIL-100(Fe) frameworks by the “impregnation-reaction-encapsulation” strategy for biodiesel production

A new, simple and effective strategy to confine dicationic acid ionic liquids (DAILs, 1,4-bis[3-(propyl-3-sulfonate)imidazolium] butane hydrogen sulfate) in the cages of a MIL-100(Fe) framework was constructed.

Immobilization of a thiol-functionalized ionic liquid onto HKUST-1 through thiol compounds as the chemical bridge

The IL@HKUST-1 catalyst was synthesized by a post-synthetic modification strategy. The introduction of ionic liquid greatly improved the acidity of the material, making it an efficient and recyclable catalyst for the esterification reaction.

"One-step production of biodiesel from Jatropha oil with high-acid value in ionic liquids" [Bioresour. Technol. 102 (11) (2011)]

Catalytic conversion of un-pretreated Jatropha oil with high-acid value (13.8 mg KOH/g) to biodiesel was studied in ionic liquids (ILs) with metal chlorides. Several commercial ILs were used to catalyze the esterification of oleic acid. It was found that 1-butyl-3-methylimidazolium tosylate {[BMIm][TS]} had high catalytic activity with 93% esterification rate for oleic acid at 140 °C but only 63.7% Jatropha biodiesel yield at 200 °C. When ZnCl2 was added to [BMIm][TS], a maximum Jatropha biodiesel yield of 92.5% was achieved at 180 °C. Addition of metal ions supplied Lewis acidic sites in ILs promoted both esterification and transestrification reactions. It was also found that the transition metal ions performed higher catalytic activity in transestrification than the ions of Group A. Mixture of [BMIm][TS] and ZnCl2 was easily separated from products for reuse to avoid producing pollutants.

Biodiesel production using alkaline ionic liquid and adopted as lubricity additive for low-sulfur diesel fuel

Preparation of biodiesel from vegetable oils, such as rapeseed oil, soybean oil and sunflower oil, catalyzed by an alkaline ionic liquid 1-butyl-3-methylimidazolium imidazolide ([Bmim]Im) was investigated in this work. The results demonstrated that [Bmim]Im exhibited high activity and the yield of biodiesel was up to 95% or more when molar ratio of methanol to vegetable oil was 6:1, ionic liquid dosage was 6 wt.%, reaction temperature was 60°C, and reaction time was 60 min. After [Bmim]Im was used for the sixth time, the yield of biodiesel still remained at about 95%. The effects of the biodiesels on the lubricity of low-sulfur diesel fuel were also investigated using the High Frequency Reciprocating Rig method, and the results showed that sunflower biodiesel and soybean biodiesel had higher lubrication performance than that of rapeseed biodiesel.

Ultrasound-assisted production of biodiesel from soybean oil using Brønsted acidic ionic liquid as catalyst

Biodiesel production from soybean oil with methanol was performed in the presence of a Brønsted acidic ionic liquid-based catalyst under ultrasound irradiation. The influences of various parameters on the transesterification reaction, including the amount of catalyst, the molar ratio of methanol to oil, the temperature and the ultrasound power, were investigated. The optimal conditions were: methanol/oil molar ratio of 9:1, 1.0 wt.% catalyst in oil, ultrasound power of 200 W, and reaction temperature of 60°C. Under these conditions, the conversion of triglycerides to fatty acid methyl esters was about 93.2% within the reaction time of 60 min.

One-step production of biodiesel from Jatropha oil with high-acid value in ionic liquids

Catalytic conversion of un-pretreated Jatropha oil with high-acid value (13.8 mg KOH/g) to biodiesel was studied in ionic liquids (ILs) with metal chlorides. Several commercial ILs were used to catalyze the esterification of oleic acid. It was found that 1-butyl-3-methylimidazolium tosylate ([BMIm][CH(3)SO(3)]; a Brønsted acidic IL) had the highest catalytic activity with 93% esterification rate for oleic acid at 140°C but only 12% biodiesel yield at 120°C. When FeCl(3) was added to [BMIm][CH(3)SO(3)], a maximum biodiesel yield of 99.7% was achieved at 120°C. Because metal ions in ILs supplied Lewis acidic sites, and more of the sites could be provided by trivalent metallic ions than those of bivalent ones. It was also found that the catalytic activity with bivalent metallic ions increased with atomic radius. Mixture of [BMIm][CH(3)SO(3)] and FeCl(3) was easily separated from products for reuse to avoid producing pollutants.