br Acknowledgement The authors thank financial support from

Acknowledgement The authors thank financial support from Visveswaraya Technological University, Belagavi, Karnataka, India, under VTU research Grants Scheme-2010-11 (VTU/Aca./2011-12/A-9/6380).
Introduction Liquid–liquid extraction is the second most important ion channel process largely used by many industries after distillation (Tsouris et al., 1994; Usman et al., 2008). Although the operation principles and dynamics of this process are well understood, increasingly stringent environment regulations, increasing cost of raw materials, high quality products and needs to reduce operational costs are required for good performance. The main aspect of liquid–liquid extraction is the efficiency of mass transfer between two liquids. For mass transfer to take place between the two liquids there needs to be sufficient contact between the phases. To achieve this, agitated columns are used. Agitated columns are preferred to static columns because of the mixing level that is achieved in them (Seader and Henley, 2006). It is in this area that more research is still being conducted and continues to be significant. This study mainly entails the research conducted using a vibrating plate extraction column (VPE). Literature review divulges that most research work has been carried out using mechanically agitated columns, however, it is limited when it comes to reciprocating plate columns and vibrating plate extractors (Rathilal et al., 2011). Reciprocating plate columns have the higher efficiency and higher throughput compared to other agitated columns (Prabhakar et al., 1988). The VPE is a modification of a reciprocating plate column (RPC).
Experimental test system and methodological approach The acetone-toluene-water system was used to conduct the experimental work on a 4.77 cm ID VPE. This is a standard test system for liquid–liquid extraction recommended by the European Federation of Chemical Engineering (EFCE, 1985) due to its high accuracy especially when gas chromatography is used. Three sieve tray hole diameters were used to test which is the most effective. The details of the three tray designs are stipulated in Table 1 below. Fig. 1 shows a schematic diagram of the experimental setup.
Experimental procedure A conductivity probe was used to control the interface level in the top settling tank by varying the rate at which the extract was removed from the column. The interface level was set at a fixed measured level below the raffinate overflow point. The agitation level was set to the required value by adjusting the frequency on the vibration motor controller. Steady state of the system was achieved in 45 min (Rathilal, 2010). A Perspex box filled with water was attached around the column between 2 plates where photographs of the droplets were taken. This box helped to reduce the effect of the curvature of the column on the size of the droplets. The drop sizes were measured using photographic techniques with the aid of Image Pro Plus software. Sauter mean diameter, d, was estimated from drop size distributions. The percentage amount of acetone extracted was measured by analysing feed samples and the raffinate sample using the gas chromatograph. The percentage of acetone extracted was estimated using the following formula: Where x and x are the mass fractions of acetone in the feed and raffinate respectively. The formula was valid since the solvent to feed ratio was kept constant at 1:1.
Results
Conclusion
Acknowledgments Gratitude and appreciation is extended to National Research Foundation for financial support of this project.
Introduction Vegetable gums have been widely used by the food industry as thickening and gelling agents, emulsifiers and stabilizers and for controlling the growth of ice and sugar crystals. Several studies (Lin and Lai, 2009; Lai and Liang, 2012; Yapo, 2009) have shown that the part of the plant being processed and the extraction conditions significantly affect the production and physico-chemical characteristics of the resulting gums. Characteristics such as the chemical composition (including the neutral sugar, ash and protein content, and the degree of esterification, methoxylation and acetylation) and molecular weight distribution affect the rheological characteristics and the function of these gums as emulsifying agents (by influencing the emulsification capacity and stability) and as gelling and thickening agents. The chemical structure of these hydrocolloids varies depending on the type of extraction and the source material, and homologues can have one or more physical properties that are useful commercially.