Utilizing ultrasonic energy for reduction of free fatty acids in crude palm oil

Recently, biodiesel production from abundant bio-sources has drawn the attention of the academic and the industrial community. In this study, crude palm oil (CPO) containing 8.7% free fatty acid content (FFA) was used as raw material. Different common types of acid catalysts (sulfuric acid, methanesulfonic acid and hydrochloric acid) were optimized to investigate the catalytic activity of each acid in the pre-treatment of CPO by the esterification process. Ultrasonic energy was used for the reduction of FFA in CPO. FFA content was measured at different sonication intervals, and the optimum time was determined. Hydrochloric acid showed the highest catalytic activity in the reduction of FFA content in CPO, as well as in converting FFA to fatty acid methyl ester (FAME). From this work, it is reasonable to conclude that there is significant enhancement in the pre-treatment of oils by applying ultrasonic energy using long sonication time.Keywords: Biodiesel, crude palm oil, free fatty acids, ultrasonic energ

Electrochemical Generation of Superoxide in Room-Temperature Ionic Liquids

We have demonstrated that superoxide ion can be generated electrochemically in room-temperature ionic-liquid solvents. In the absence of impurities, cyclic voltammetry showed that the super oxide ion is stable in these solvents. Similar superoxide ion chemistry has previously been demonstrated in volatile and environmentally suspect aprotic solvents such as dimethyl formamide and acetonitrile. However, ionic liquids are nonvolatile and should minimize the problems of secondary solvent waste. It is proposed that the resultant superoxide ion can be used to perform low temperature oxidation of wastes. Low-temperature oxidation of waste solvents can provide a much needed alternative to high-temperature waste incinerators, whose use is greatly complicated by regulatory requirements and locating suitable sites

Preparation of sustainable activated carbon-alginate beads impregnated with ionic liquid for phenol decontamination

Powder activated carbon (PAC), derived from calligonum pollygonides, was successfully modified with the ionic liquid (IL) trihexyltetradecylphosphonium bromide ([PC6C6C6C14][Br]) in the presence of sodium alginate and characterized using SEM, FTIR and TGA. PAC, granular AC (GAC), AC-alginate and AC-Alg-IL bead were assessed for the removal of phenol from aqueous media via batch adsorption. Both PAC and AC-Alg-IL beads displayed high adsorption capacities, 123 mg/g and 78 mg/g, respectively, under optimized conditions. In contrast, GAC gave a much lower adsorption capacity than AC-ALG-IL beads, indicating that AC-ALG-IL beads are superior as potential adsorbents for this industrial application. Theoretical studies showed that the pseudo-second-order kinetic and Freundlich isotherm models were suitable to describe the adsorption process. The interaction between phenol and AC-Alg-IL beads was analyzed using the conductor-like screening model for realistic solvents (COSMO-RS). It has been concluded that AC-Alg-IL beads can be used as an efficient adsorbent for phenol and other organic compounds

COSMO-RS Prediction for Choline Chloride/Urea Based Deep Eutectic Solvent: Chemical Structure and Application as Agent for Natural Gas Dehydration

In recent years, green solvents named deep eutectic solvents (DESs) have been found to possess significant properties and to be applicable in several technologies. Choline chloride (ChCl) mixed with urea at a ratio of 1:2 and 80 °C was the first discovered DES. In this article, chemical structure and combination mechanism of ChCl: urea based DES were investigated. Moreover, the implementation of this DES in water removal from natural gas was reported. Dehydration of natural gas by ChCl:urea shows significant absorption efficiency compared to triethylene glycol. All above operations were retrieved from COSMOthermX software. This article confirms the potential application of DESs in gas industry

A quantitative prediction of the viscosity of amine based DESs using Sσ-profile molecular descriptors

International audienceIn recent years, the preparation of deep eutectic solvents (DESs) using amines as hydrogen bond donors (HBD) has been reported by several research groups. One of the potential use of this type of DESs is in the field of CO2 capture, where the viscosity of the solvent before and after the absorption is of paramount importance. Since the number of possible combinations of DESs is huge, a mathematical model for the predicting of the viscosity of DESs at different temperatures is very important.In this work, a new mathematical model for the prediction of amine-based DESs viscosities using the quantitative structure property relationships (QSPR) approach is presented. A combination of multilinear regression (MLR) and artificial neural networks (ANN) methods is used for the development of the model. A data set of 108 experimental measurements of viscosity of five amines-based DESs, taken from the literature, is used for the development and subsequent verification of the model. The more appropriate model is determined by a dedicated statistical analysis, in which the most significant descriptors are preliminary determined. The results show that the proposed models are able to predict the DESs viscosities with very high accuracy, i.e. with a R2 value of 0.9975 in training and 0.9863 for validation using the ANN model and R2 value of 0.9305 for the MLR model. The retrieved model can be considered as a very reliable tool for the prediction of DESs viscosity when experimental data are absent. In turn, this can provide useful guidelines for the synthesis of low-viscosity DESs able to minimize energy requirements associated to their processing (e.g. power required for pumps), thus fostering their industrial-scale implementation

Utilizing of 1-Hexyl-1-Methyl-Pyrrolidinium Bis (Trifluoromethyl-Sulfonyl) Imide as Medium for Electrochemical Generation of Superoxide Ion-Radical

The superoxide ion-radical was generated and analysed electrochemically using cyclic voltammetry (CV) technique from oxygen dissolved in a room-temperature ionic liquid, 1-Hexyl-1-methyl-pyrrolidinium bis (trifluoromethylsulfonyl) imide, at atmospheric pressure. It was found that the generated superoxide ion was stable which indicates its possible use for further useful applications. ABSTRAK: Ion radikal superoksida dihasil dan dianalisa secara elektrokimia menggunakan teknik voltammetri berkitar (cyclic voltammetry (CV)) daripada oksigen yang dilarutkan dalam larutan ionik pada suhu bilik, 1-Hexyl-1-methyl-pyrrolidinium bis (trifluoromethylsulfonyl) imida, pada tekanan atmosfera. Didapati bahawa ion superoksida yang terhasil adalah stabil. Ini menunjukkan ia berkemungkinan berguna dalam aplikasi lain

Effectiveness of using deep eutectic solvents as an alternative to conventional solvents in enzymatic biodiesel production from waste oils

Ionic liquids (ILs) have been proposed as a more benign replacement to toxic and volatile organic solvents in enzymatic biodiesel production, used to minimize methanol inhibition effect and enhance the stability of immobilized enzyme. Despite their several advantages, ILs are expensive, which renders the overall process unfeasible. In this work, the use of low-cost deep eutectic solvents (DESs) has been investigated as a new reaction medium for enzymatic biodiesel production from waste oils. A DES composed of chlorine-chloride and glycerol (ChCl:Gly) was tested and its effectiveness was compared to 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6], which has shown positive results. To decrease the viscosity of ChCl:Gly DES, ternary ChCl:Gly:water DESs with different water contents were prepared and tested. Despite lower cost compared to ILs, without successful repeated reuse of the DES-immobilized lipase system, their advantages remain theoretical. Therefore, the reusability of the DES-Novozym®435 system in consecutive cycles was examined. It was shown that 34% biodiesel production yield could be achieved in ChCl:Gly at 1:2 molar ratio, compared to 23% when [bmim][PF6] was used. The yield increased further, when the ternary DES of ChCl:Gly:water (1:2) with 3 wt% water was used, reaching 44%. By removing the by-product glycerol, the reusability of the DES-immobilized system was improved, with better results achieved using 1-butanol compared to using ethylene glycol. Keywords: Biodiesel, Deep eutectic solvent, Ionic liquids, Immobilized lipase, Reusabilit

Recent progress of MXene as a cocatalyst in photocatalytic carbon dioxide reduction

Due to the excessive consumption of fossil fuel resources and the emission of a substantial quantity of CO2 into the environment, it is urgent to develop clean energy solutions. In order to reduce carbon emissions from the source, it is effective approach to convert CO2 into various renewable energy fuels. Inspired by the photosynthesis of green plant, CO2 is converted into clean fuel with the aid of catalysts. Regarding the separation and transfer of photogenerated charge carriers, and inadequate adsorption and activation of CO2 on the surface of catalysts, the current semiconductors utilized in photocatalysis have low efficiency. As a result, the current efficiency of photocatalysts is far from meeting the need for practical industrial demands. MXene materials, for example Ti3C2Tx (9980 S cm−1), have emerged as a promising candidate for CO2 reduction due to the significant number of active sites for functional groups, high conductivity and low defects, large surface areas, and outstanding visible light photoelectronic properties. This review provides a critical overview of the recent progress regarding MXene as a co-catalyst in photocatalytic CO2 reduction systems. We systemically explore the fundamental principles and reaction mechanisms associated with separating and transferring photogenerated charge carriers. Additionally, we investigate the basic properties of MXene as a co-catalyst in the context of CO2 reduction. Furthermore, this review also elucidates the impacts of the microstructure of photocatalysts on enhancing photocatalytic performance. Finally, the challenges and opportunities in using MXene as a co-catalyst for CO2 reduction have been presented to inspire further research in this field

Boron extraction from aqueous medium using novel hydrophobic deep eutectic solvents

[Display omitted] •Deep eutectic solvents (DES) are developed for the first time for boron extraction.•Hydrophobic DES are prepared with 2-methyl-2,4-pentanediol (MPD) as hydrogen bond donor.•Up to 91% extraction efficiency was achieved by thymol:MPD DES.•Stable MPD-boric acid complexes are responsible for boron extraction. In this work, four novel hydrophobic deep eutectic solvents (DES) were prepared from a combination of menthol (Men) or thymol (Thy) as hydrogen bond acceptors (HBA) with 1-decanol (Dec) or 2-methyl-2,4-pentanediol (MPD) as hydrogen bond donors (HBD), for the extraction of boron from aqueous solutions. The DESs were characterized in terms of their physical (density, viscosity and water content), and thermal (melting point and decomposition temperature) properties. The DES’ critical properties were estimated using a group contribution method based on the modified Lydersen-Joback-Reid and Lee-Kesler mixing rules. Later, the solvents were evaluated for their capability to extract boron from different aqueous solutions and the extraction and stripping efficiencies were used as performance evaluation criteria. The hydrophobic DES made with MPD showed high extraction efficiency of boron (in the boric acid form), up to 90.1% and 83.2% for Thy:MPD and Men:MPD, respectively. Stripping of boron from the DES phase was done using 0.1 M NaOH as stripping solution. Moreover, FTIR spectra were recorded before and after extraction of boron to better understand the extraction mechanism. The extraction was due to the complexation between MPD in the DES and boric acid. The hydrophobic DESs offer an environmentally benign alternative as extractants, and allow for the use of water miscible diols, like MPD, in the extraction of boron from aqueous environments such as industrial wastewater or boron-rich brines