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Abstract : A Comparative Study on the Performance of Fiber-Based Biosorbents in the Purification of Biodiesel Derived from Camelina sativa
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Abstract: Biodiesel has received great interest as a promising substitute for petrodiesel. Biodiesel purification which follows the transesterification process is typically carried out using a wet washing process that generates large amounts of wastewater. Consequently, alternative methods are emerging as sustainable options for biodiesel purification. One of such methods is a dry washing process. In this paper, the performance of three dry washing media (commercially available BD-Zorb, sawdust and wood shavings) were evaluated as potentially suitable options for the purification of biodiesel derived from Camelina sativa. The results indicate that for the crude camelina biodiesel with an initial soap content of 9007 ppm, BD-Zorb exhibited the best purification performance. The soap removal capacity of BD-Zorb, sawdust, and wood shavings was 51.1 mL/g, 24.4 mL/g, and 9.4 mL/g respectively. The primary mechanism of soap removal using sawdust and wood shavings media was physical filtration and adsorption. While for adsorbent BD-Zorb, soap removal mechanism included adsorption and ion exchange due to the existence of a small amount of resins. The ion exchange led to a high acid number (1 mg KOH/g) of the purified biodiesel, and failed to meet the ASTM D6751 specifications (<0.5 mg KOH/g). Keywords: Drying washing, purification of biodiesel, adsorbent, wood waste, Camelina sativa.Download Full Article |
Abstract : A Comparative Study on the Performance of Fiber-Based Biosorbents in the Purification of Biodiesel Derived from Camelina sativa (2)
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Abstract: Biodiesel has received great interest as a promising substitute for petrodiesel. Biodiesel purification which follows the transesterification process is typically carried out using a wet washing process that generates large amounts of wastewater. Consequently, alternative methods are emerging as sustainable options for biodiesel purification. One of such methods is a dry washing process. In this paper, the performance of three dry washing media (commercially available BD-Zorb, sawdust and wood shavings) were evaluated as potentially suitable options for the purification of biodiesel derived from Camelina sativa. The results indicate that for the crude camelina biodiesel with an initial soap content of 9007 ppm, BD-Zorb exhibited the best purification performance. The soap removal capacity of BD-Zorb, sawdust, and wood shavings was 51.1 mL/g, 24.4 mL/g, and 9.4 mL/g respectively. The primary mechanism of soap removal using sawdust and wood shavings media was physical filtration and adsorption. While for adsorbent BD-Zorb, soap removal mechanism included adsorption and ion exchange due to the existence of a small amount of resins. The ion exchange led to a high acid number (1 mg KOH/g) of the purified biodiesel, and failed to meet the ASTM D6751 specifications (<0.5 mg KOH/g). Keywords: Drying washing, purification of biodiesel, adsorbent, wood waste, Camelina sativa.Download Full Article |
Abstract : Preparation and Characterization of Cellulose Membrane Modified with β-Cyclodextrin for Chiral Separation
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Abstract: In this study, it is first time to obtain a complete separation of using β-cyclodextrin (β-CD) modified cellulose microfiltration membrane. Commercially cellulose membrane with the pore diameter of 0.22μm was functionalized with β-cyclodextrin (β-CD) by aldolization at the solid–liquid interface. Filtration experiments were carried out using a dead-end filtration cell holding a flat sheet membrane with effective area of 36 mm2. Aqueous solution of racemic tryptophan (0.05g/L, 150 mL) was forced to permeate through the cellulose membrane immobilized by β-CD at a flow rate of 0.1 ml/min through the membrane microdevice. Chiral ligand exchange chromatography was used to determine the concentration and ratio of D- and L-tryptophan in the filtrate. A complete separation of racemic tryptophan can be obtained by using this novel composite membrane-based separation system. In addition, a multi-stage filtration separation was applied in order to obtain higher permselectivity. The objective of this study is to obtain an easy prepared chiral membrane with good reproducibility and can be applied to a variety of chiral separations. Keywords: Cellulose membrane, Enantiomeric separation, Glutaraldehyde, Tryptophan, Multi-stage filtration.Download Full Article |
Abstract : Removal of Nickel(II) from Aqueous Solution by Complexation-Ultrafiltration with Polyvinyl Pyrrolidone
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Abstract: This study confers insight into the removal of Nickel(II) from aqueous solution by complexation-ultrafiltration (CP-UF) technique with water-soluble polymer polyvinyl pyrrolidone (PVP). The whole experiment process includes five parts: pre-treatment, CP-UF, concentration, decomplexation and regeneration of polymer. Numerous factors affecting the retention rate of Nickel(II) (RNi) and permeate flux (J), such as pH, loading ratio, transmembrane pressure (TMP), complexation time and added salt have been investigated. In the CP-UF process, RNi reaches nearly 94% while pH of 7, loading ratio of 4, TMP of 1.0 bar, temperature of 250C, complexation time of 30 min are chosen to be the optimal parameters. In the process of concentration, J declines slowly and RNiis very high at loading ratio of 4 and pH of 7. Nickel ion concentration in the retentate solution increases linearly with volume concentration factor. In the process of decomplexation, the decomplexation percentage of nickel(II)-PVP complex reaches 42%. The binding capacity of the regenerated PVP is close to that of fresh PVP, and the recovery percentage of binding capacity is higher than 90%.. Keywords: Nickel(II), Polyvinyl pyrrolidone, Complexation, Ultrafiltration.Download Full Article |
