Studies on the Extraction of Aromatics with Sulpholane and its Combination with Thiodiglycol

Liquid-liquid equilibria for the systems: toluene-heptane-sulpholane, tolueneheptane- sulpholane plus thiodiglycol at 40°C, and benzene-heptane-sulpholane plus thiodiglycol and benzene-heptane-sulpholane plus 9% water at 110°C have been studied. The results of the combined solvents have been compared with those obtained with sulpholane containing up to 9%water. Several advantages of combined solvents are discussed. The selectivities of the mixed solvents for different hydrocarbon types have been calculated from the limiting activity coefficients determined by gas Chromatography

Some Furfural Group of Solvents for the Extraction of Aromatics

Three furfural group of solvents have been tried for the separation of aromatics from non-aromatics by extraction. The performance of the solvents has been compared in respect of their selectivities, capacities and phase equilbrium diagrams

Study of Some Sulphur-group Solvents for Aromatics Extraction by Gas Chromatography

Nineteen organosulphur solvents have been studied by gas chromatography as potential solvents for the extraction of aromatics. The activity coefficients of nine typical hydrocarbon solutes have been determined in these solvents at three temperatures. From the activity coefficient data, the selectivities of all the solvents have been calculated for benzene with respect to each of the other hydrocarbons in order to screen them for extraction studies. Solvent losses in the g.C.column were also studied

Study of Some Sulphur-group Solvents for Aromatics Extraction by Gas Chromatography

Nineteen organosulphur class of solvents have been studied by gas chromatography for potential use as solvents for the extraction of aromatics. The activity coefficients of nine typical hydrocarbon solutes have been determined in these solvents at three temperatures. From the activity coefficient data, the selectivities of all the solvents have been calculated for benzene with respect to each of the other hydrocarbons in order to screen them for extraction studies. Solvent losses in the g.C. column are also studied

BASIC CONSIDERATIONS IN THE SELECTION OF SOLVENTS FOR AROMATICS EXTRACTION

Basic properties required, for solvents suitable for extraction of aromatics from hydrocarbon mixtures, have been discussed. The physical properties and chemical structures of selective solvents, used commercially for the separation of light aromatics, have been compiled. Based on these properties and chemical structures, some generalizations have emerged which have been discusSed and which serve as guiding principles in the selection of new solvents for specific uses. The' production of light aromatics, benzene, toluene and xylenes, for gasoline and petrochemical end use has increased rapidly in recent years, all over the world, due to the ever increasing demand for plastics, synthetic fibres and a host of synthetic organic dyes and intermediates. Prior to 1941 the main source of these light aromatics was coal carbonization and subsequent distillation of the coal-tar byproduct. Petroleum-based aromatics have been selected to cope with the increasing demand. The demand for these aroma.tics (BTX) , for chemicals and gasoline will be about 0.23 and 1 million barrels per calendar day respectively in U.S.33in this decade. It is expected that in the year 197'5the demand for BTX aromatics in Western Europe will exceed 3.83 million tonnes per annum33. In India, the tentative demand'" estimated for these aromatics is stated as 100,000tons/yr. of benzene and 55,000 tonsl yr. of ortho and para-xylene by the end of the fourth plan period. The production of benzene and toluene has already started at the Koyali Refinery in Gujarat

Water Tolerability of Gasoline-Methanol Blends

Miscibilities of various blends of gasoline-methanol with or without solubilizing agents in presence of water at different temperatures varying from - 2°C to 30°C have been studied to determine the water tolerability of these blends. The life of these blends under three different Indian weather conditions has been estimated. The entire data were compared with those obtained earlier with gasoline-ethanol blends. The study shows that water tolerance of the blends is increased with increasing alcohol concentration and the presence of higher amount of aromatics in gasoline. Rate of absorption of moisture from atmosphere is quite low and blends with 15%methanol or 20% ethanol can be fairly stable in use particularly in the summer months