Microalgal Lipid Extraction and Evaluation of Single-Step Biodiesel Production

This work examined solvent extraction of lipid from microalgae for production of renewable biofuels, thereby allowing appropriate selection of solvent and extraction methods. The results of this study revealed that the mixture of chloroform and methanol (C/M) at the ratio of 2:1 (v/v) could extract the highest amount of total lipid from algae, while hexane was found to be a good solvent, concerning the selectivity for nonpolar targeted lipids such as mono-, di- and tri-glycerides. As far as the extraction methods are concerned, applying ultrasound could accelerate the rate of lipid extraction from algae with tough cell walls such as Chlorella vulgaris. On the other hand, ultrasound and microwave assisted extraction techniques added no benefits to the extraction of lipid from powder of Haematococcus pluvialis whose cell wall was previously damaged. Other than lipid extraction, this paper concerns with the development of transesterification process for algal lipid using C. vulgaris as a model system. Here, the effects of the amount of catalyst, alcohol to biomass ratio and reaction time on biodiesel yield were investigated. We also studied a single-step biodiesel production where extraction and transesterification simultaneously take place, and made comparison between this method and the conventional two-step biodiesel production process

Physicochemical Properties of Low Transition Temperature Mixtures in Water

A new generation of designer solvents, low transition temperature mixtures (LTTMs) could be the ideal solvent for the separation of the main biopolymers in lignocellulosic biomass such as lignin, cellulose and hemicellulose. The separated biopolymers have prospective to be converted into high valuable products. LTTMs can be synthesized from two natural high melting point materials through hydrogen bonding interactions. The objective of this research was to study the effects of water in the physicochemical properties of LTTMs such as hydrogen bonding, thermal stability and lignin solubility. LTTMs were prepared in the presence and absence of distilled water with malic acid as the hydrogen bond donor (HBD) and sucrose as hydrogen bond acceptor (HBA). The molar ratio of malic acid to sucrose was fixed at 1:1. Based on the fourier transform infrared spectroscopy (FTIR) analysis, the FT-IR spectra of all the LTTMs shown representative peak of carboxylic acid group of malic acid turned broader at 1,710 cm-1 for the C=O group. Nevertheless, the peaks involved in the H-bonding due to the formation of LTTMs shifted and became broader within 2,500 - 3,600 cm-1 for the OH groups of carboxylic acid and alcohols in the presence of water. The degradation temperature of LTTM was not affected by the addition of water which remained at 400 K. In addition, the LTTM with water had increased the lignin solubility from 6.22 to 6.38 wt% without affecting the thermal behaviour of LTTMs

Pretreatment and Bentonite-based Catalyzed Conversion of Palm-rubber Seed Oil Blends to Biodiesel

AbstractPretreatment of pre-blended palm and rubber seed oil (50:50) was studied. A parametric study to determine the effect of alcohol-to-oil ratio, catalyst loading and reaction temperature on free fatty acid (FFA) content was also conducted. Interestingly, the FFA percentage of pre-blended feedstock has been reduced significantly from 20% to below 2%. The optimum value for the reduction of FFA was found to be 1.5wt. % catalyst, alcohol-to- oil ratio 6:1, 62°C reaction temperature at constant stirring speed (400rpm) and reaction time 1.5hours. NaOH/bentonite was also investigated and characterized as a solid heterogeneous catalyst for transesterification. The characterization was conducted by FTIR and XRD analysis. The catalyst showed good results by producing 92 wt% fatty acid methyl esters at reaction temperature of 62°C and reaction time of 3hours