Thiophene extraction in PEG - hexan - water based systems

The effect of individual and multicomponent additives of sodium chloride, iron chloride, sodium nitrate and 1-methyl-2-pyrrolidone on the interfacial distribution of thiophene in the systems polyethylene glycol 1500 (PEG-1500) - hexane - water and polyethylene glycol 8000 (PEG-8000) - hexane - water has been studied in this investigation. It was found that in most cases, the introduction of a small amount of individual and joint additives increases the extraction of thiophene from the organic phase to the aqueous.

Interphase distribution of a number of polybasic carboxylic acids in aqueous two-phase systems based on polyethylene glycol-1500

In this work, we studied the interphase distribution of a number of polybasic carboxylic acids, in particular, malic, succinic, glutaric, citric, ascorbic and tartaric in two-phase aqueous systems polyethylene glycol-1500 (PEG-1500) - sodium sulfate - water and PEG-1500 - ammonium sulfate - water. Using the spectrophotometric method of analysis, quantitative characteristics (interfacial distribution and degree of recovery) of the extraction of carboxylic acids were determined. In conclusion, it was found that the considered two-phase aqueous systems are promising in the process of extraction of polybasic carboxylic acids. In particular, the system polyethylene glycol 1500 - sodium sulfate - water has effective extraction properties for succinic malic and ascorbic acids. On the other hand, depending on the composition of the extraction systems, the quantitative characteristics for citric, glutaric and tartaric acids practically do not differ.

Study of caffeine and coumarin extraction kinetics in an aqueous two-phase system based on polyethylene glycol 1500

Caffeine and coumarin are organic compounds of plant origin, which have biological activity and have found wide application in medicine, pharmaceutical, perfumery and food industries. Recovery of caffeine and coumarin from aqueous solutions using liquid-liquid extraction is the most effective method. In the present work the kinetic dependences of caffeine and coumarin in the aqueous two-phase system (ATPS) of PEG 1500 - Na2SO4 - H2O were experimentally obtained. It was established that equilibrium in the system is achieved after 17 minutes for caffeine and after 12 minutes for coumarin. The effect of ultrasound on the extraction rate of caffeine and coumarin in an aqueous two-phase system was also studied.

Melting/Solidification Processes of PEG 1500 in Vertical and Horizontal Annular Enclosure

In this paper, the primary aim is to look at the fundamental melting/solidification processes of polyethylene glycol 1500 (PEG 1500) for energy storage – insulation to prolong the cooling time of pipelines in unexpected shut-down conditions, prevent/minimize the wax deposition, and hydrate formation. Polyethylene glycol 1500 was selected because its melting temperature is >317 K making it a suitable candidate as lagging material to prevent wax deposition and hydrate formation in subsea oil pipelines. Experimental apparatus was designed with the Perspex to give an insight into the melting process. Vertical and horizontal annular geometries were used to consider the real-life cases. The vertical annular enclosure length is 950 mm and 34 mm width (Height/Width=27.94). The horizontal annular enclosure length is 300mm and 15.9 mm width (Height/Width=18.87). The thermocouples and camera are used to collect the data for three cases of inner wall temperature of 333 K,343 K and 353 K where is the heat added to the phase change material (PCM) for both cases. The main conclusions are: i) the horizontal annular case melt faster than the vertical case, in particular, at higher heating surface temperature of 353 K, ii)The temperature of the inner region was remained hot for long time which provide a good evidence that support the concept of using the PCM as heat storage–insulation material; iii) the melting percentage for horizontal case is 100% higher from the melting percentage of vertical case at 333 K which reduced to about 20% for 343 K, iv) increasing the heating surface temperature substantially reduces the total melting time for both orientations.