Long-Term Storage Stability of Epoxides Derived from Vegetable Oils and Their Methyl Esters

Epoxidized plant seed oils have received much attention in recent years to replace conventional lubricant basestocks in the current lubricant market. Although there is an increase in the productivity of epoxides, showing a solution for future energy insecurity, there still remains some concern for commercialization due to its susceptibility during long-term storage. Therefore, in order to commercialize the epoxides, they should maintain their integrity (physical and chemical) in all aspects. The objective of this study is to investigate the effect of various storage conditions on quality-indicative parameters for epoxides, such as acid value, oxirane oxygen content, and alpha glycol content for epoxidized waste cooking oil, castor oil, and their epoxidized methyl esters. Aforementioned quality indicative parameters for epoxides were investigated after every 3 months over a period of 12 months. During the storage period, epoxides were stored in three different groups at different temperatures (room temperature, 4 °C) and different environmental conditions (closed to air in the dark, closed to air and exposed to light). The analysis was carried out at regular intervals to monitor the quality-indicative parameters for four epoxides (two oil derived epoxides and two methyl esters derived epoxides). The results of the study revealed that epoxides stored at ambient temperature (closed to air and exposed to light) were highly more unstable than those at the other storage conditions. Likewise, epoxidized methyl esters stored at the same condition were found to degrade at a faster rate than epoxidized oils

COSMO-RS-Based Screening of Antisolvents for the Separation of Sugars from Ionic Liquids: Experimental and Molecular Dynamic Simulations

The use of ionic liquids (ILs) in the biorefinery process has been increasing for the past few decades. In biorefinery, the separation process with respect to sugars needs to be evaluated for an efficient process design. Therefore, the present work aims to investigate the separation of sugars and ILs by means of a precipitation process using an antisolvent method. For this purpose, both theoretical and experimental studies were conducted. Initially, the conductor-like screening model for real solvents model was employed to screen the suitable antisolvents for the separation of sugars from the ILs. From the screening study, dichloromethane (DCM) and 1,2-dichloroethane were found to be the better antisolvents for the separation process. With the selected antisolvents, precipitation experiments were conducted for the mixtures involving four different sugars and three ILs at different experimental conditions. The process variables such as different antisolvents, sugars, ILs, antisolvent–IL molar ratios, and temperatures were examined in terms of their effect on sugar removal and IL recovery. DCM was found to be the most suitable antisolvent in this study with 90–99% of sugar removal and 80–98% of IL recovery. Further, molecular dynamics simulations were adopted to understand the structural properties of carbohydrates with ILs and antisolvents via interaction energies, hydrogen bonding, and coordination numbers. It was observed that the interaction energy between the sugars and IL plays a critical role in the removal of sugar. Higher the interaction energy between the sugars and IL, lower is the sugar removal

Solid Liquid Equilibrium of Cellobiose, Sucrose, and Maltose Monohydrate in Ionic Liquids: Experimental and Quantum Chemical Insights

As a substitute of fossil fuels, lignocellulosic biomass is a potential feedstock for the production of energy and value-added chemicals. The present work reports the solubility (solid–liquid equilibria, SLE) of disaccharides, namely, d-(+)-cellobiose, sucrose, and maltose monohydrate in two ionic liquids (ILs) by a combined approach using experiments and predictions with the continuum solvation model. The screened ILs, namely, 1-ethyl-3-methylimidazolium thiocyanate ([EMIM]­[SCN]) and tris­(2-hydroxyethyl)­methylammonium methylsulfate [TMA]­[MeSO₄], were then used as solvents to measure the SLE at a temperature range of 302.15–353.15 K. The IL [EMIM]­[SCN] gave a higher solubility as compared to [TMA]­[MeSO₄] irrespective of the disaccharide. The solubility trend within the disaccharide was similar in both the ILs, and it followed: maltose monohydrate > sucrose > d-(+)-cellobiose. The interactions were further confirmed from the quantum chemical calculations by investigating the interaction energy and HOMO–LUMO energy gap between ILs and disaccharides. The thermodynamic function of dissolution such as Δ_dissol.^o<i>H</i> gave positive values for all of the systems, thereby indicating an endothermic process. Experimental solubility data were also successfully correlated with the local thermodynamic models such as nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) which gave a deviation of less than 5%

Production of first and second generation biofuels: A comprehensive review

Sustainable economic and industrial growth requires safe, sustainable resources of energy. For the future re-arrangement of a sustainable economy to biological raw materials, completely new approaches in research and development, production, and economy are necessary. The 'first-generation' biofuels appear unsustainable because of the potential stress that their production places on food commodities. For organic chemicals and materials these needs to follow a biorefinery model under environmentally sustainable conditions. Where these operate at present, their product range is largely limited to simple materials (i.e. cellulose, ethanol, and biofuels). Second generation biorefineries need to build on the need for sustainable chemical products through modern and proven green chemical technologies such as bioprocessing including pyrolysis, Fisher Tropsch, and other catalytic processes in order to make more complex molecules and materials on which a future sustainable society will be based. This review focus on cost effective technologies and the processes to convert biomass into useful liquid biofuels and bioproducts, with particular focus on some biorefinery concepts based on different feedstocks aiming at the integral utilization of these feedstocks for the production of value added chemicals.First generation biofuel Second generation biofuel Biorefinery Biomass Bio-oil

Thermal Degradation Kinetic Study of Rubber Seed Oil and Its Methyl Esters under Inert Atmosphere

Nonedible vegetable oil feedstocks are promising for sustainable production of biodiesel. Thermal decomposition characteristics of the feedstocks and their biodiesel are crucial for handling and quality control. Thermal degradation of rubber seed oil (RSO) and rubber seed oil methyl esters (ROME) was investigated with the help of thermogravimetry. The samples were pyrolyzed from 30 to 800 °C at heating rates of 10 °C/min to 50 °C/min with a 10 °C/min increment under a nitrogen atmosphere. The temperature window for thermal degradation of RSO and ROME was shifted toward a higher range as the heating rate increased from 10 °C/min to 50 °C/min. A transesterification reaction leads to a decrease in the molecular weight of triglycerides present in the sample (RSO), and this causes a lower thermal stability of the produced product (ROME). Fourier transform infrared (FT-IR) analysis of evolved gaseous products during pyrolysis revealed the formation of water, carbon dioxide, carbon monoxide, and saturated (alkanes) and unsaturated (alkenes) aliphatic hydrocarbons. Friedman (FRD), Flynn–Wall–Ozawa (FWO), modified Coat–Redfern (MCR), and Kissinger (KM) methods and Avrami theory were applied to calculate the values of activation energy (<i>E</i>), order of reaction (<i>n</i>), and enthalpy (Δ<i>H</i>). Furthermore, the pre-exponential factor (<i>A</i>), entropy (Δ<i>S</i>), and Gibbs free energy (Δ<i>G</i>) were also calculated

Multiscale modelling strategies and experimental insights for the solvation of cellulose and hemicellulose in ionic liquids

<p>The present study investigates the dissolution behaviour of cellulose and hemicellulose in potential ionic liquids (ILs) using both the quantum chemical and experimental validation. For converging upon the recommended IL, 1428 ILs consisting of 42 cations and 34 anions were studied with the conductor like screening model for real solvents (COSMO-RS) model. Based on the infinite dilution activity coefficient of the components in IL, the selected anions and cations were visualised by observing their interactions with cellulose and hemicellulose using interaction energies, natural bonding orbital analysis and molecular dynamics simulations. The dissolution order of cellulose and hemicellulose in ILs was primarily determined by the evaluation of hydrogen bonds between the oxygen atom of anion and hydroxyl proton of cellulose/hemicellulose. From this discernible fact, the anion of the IL was observed to play a leading role in the solvation process as compared to the cation. Eventually, acetate [OAc]^– anion and 1-ethyl-3-methylimidazolium [EMIM]⁺ cation were found to be good candidates for the dissolution of cellulose and hemicellulose. This was further confirmed by the measurement of solid-liquid equilibria with cellulose and hemicellulose. The regenerated cellulose powder was then characterised by Fourier transform spectroscopy(FTIR), X-ray diffraction (XRD) and Thermal gravimetric analysis (TGA).</p

Comparative study of physicochemical and rheological property of waste cooking oil, castor oil, rubber seed oil, their methyl esters and blends with mineral diesel fuel

In this work, physicochemical properties and rheological behaviour of waste cooking oil (WCO), castor oil (CO), rubber seed oil (RSO) and their methyl esters (ME), as well as ME blends (5, 10 and 15 vol%) with diesel fuel were investigated. Rheological properties of samples were measured in the range of 25–80 °C temperature and 5–300 s−1 shear rate. Similarly, rheological behaviour of WCO, CO and RSO based methyl esters (WCOME, COME, ROSME) and its blends (5, 10, and 15 vol%) with diesel fuel were also studied. Power law model was used to study the flow behaviour of all the samples. The viscosity behaviour of oils (WCO, CO and RSO), methyl esters (WCOME, COME and RSOME) and their blends with diesel fuel showed Newtonian nature in the temperature range of 25–80 °C. The viscosity values of the chemically modified oil samples (via transesterification) were found to be lower than the original oil samples. However, WCO, CO and their methyl esters showed a slight deviation from Newtonian behaviour between shear rate intervals of 5–100 s−1. The dynamic viscosity of RSO (25.58 mPa.s) was less than that of WCO (49.91 mPa.s) and CO (338.08 mPa.s). At 40 °C, the kinematic viscosity values of RSOME (3.81 mm2/s) and WCOME (3.36 mm2/s) were lower than the value of COME (10.59 mm2/s). The dynamic viscosities of the samples were found to be dependent on fatty acids chain length, unsaturation and temperature. According to fatty acid composition and physicochemical properties of the oils samples, WCO, CO and RSO are suitable for substituting edible feedstock to make biodiesel production sustainable. The fuel properties of the methyl esters and their blends with diesel were estimated as per ASTM D6751 biodiesel standards

Molecular Dynamic Simulations for the Extraction of Quinoline from Heptane in the Presence of a Low-Cost Phosphonium-Based Deep Eutectic Solvent

The present study aims at the extraction of a polyaromatic hydrocarbon from fuel oils using a novel low-cost deep eutectic solvent (DES). The DES is prepared by mixing the hydrogen bond acceptor (HBA; methyltriphenylphosphonium bromide, MTPB) and hydrogen bond donor (HBD; ethylene glycol) at a molar ratio of 1:4. The liquid–liquid equilibrium is then measured at ambient condition. The classical molecular dynamic (MD) simulation technique is then employed to investigate and compare the experimental phase behavior of a DES–quinoline–heptane ternary system. For performing the MD simulations, two experimental feed points are considered which gave high selectivity and distribution coefficient values. The interaction energies of different species and the structural properties such as radial distribution functions, average number of hydrogen bonds, and spatial distribution functions (SDFs) are then computed. It is found that the cation within the HBA, namely, MTP, possesses favorable interactions with quinoline when compared to HBD or anion (Br). MTP here acts as a HBA and contributes to the hydrogen bonding with quinoline, which results in higher experimental selectivity values. The calculations of SDFs further reveal the fact that the DES molecules are evenly distributed around the active sites of the quinoline molecule, whereas heptane molecules are found to be distributed around the nonactive sites of the aromatic ring