Isopropyl Alcohol-Sodium Sulfate-Water System. Liquid-Liquid Equilibria.

Abstract

D uring t h e sulfonation of petroleum d i s t i l l a t e s for highly refined white o i l s , oil-soluble mahogany sulfonic a c i d s a r e obtained as a by-product i n t h e sour oil. T h i s oil may b e considered a heterogeneous system, a s it c o n t a i n s some of the s p e n t sulfuric acid not separated with t h e a c i d sludge p h a s e and t r a c e s of sulfur dioxide formed by redox s i d e reactions. T h e corresponding sodium s o a p may b e obtained a s a crude product by neutralization with sodium hydroxide and extraction from t h e refined oil with a q u e o u s alcoholic solutions. T h e crude extract, referred t o a s raw s o a p , is e s s e n t i a l l y a n aqueous alcoholic solution of mahogany sulfonates and oil, sodium sulfate, and t r a c e s of sodium sulfite.In t h e c o u r s e of s e v e r a l experiments, i t w a s observed t h a t when aqueous ethyl alcohol w a s u s e d as t h e extracting solvent, t h e raw s o a p could b e separated from t h e refined neutral oil a s a homogeneous solution, whereas with isopropyl alcohol t h e raw s o a p further separated into two individual layers.A n a l y s e s have shown that i n s u c h i n s t a n c e s t h e lower s o a p p h a s e w a s mainly a n aqueous solution of sodium sulfate, while t h e upper s o a p p h a s e w a s a n alcoho!ic solution containing most of t h e available sodium sulfonates.Solubility d a t a for sodium s u l f a t e i n aqueous solutions of ethyl and isopropyl alcohols were required t o permit a thorough examination of t h e p o s s i b l e application of alcohol for t h e removal of inorganic s a l t s (mainly sodium sulfate) from t h e raw s o a p by either precipitation or solution in water. B y t h i s means and after solvent evaporation, a salt-free solution of sodium sulfonates in oil may b e obtained.Solubility d a t a for t h e ternary s y s t e m ethyl alcohol-sodium sulfate-water have been reported by Seidell (3) and h a v e been extensively studied by Vener and Thompson (5). T h e latter authors s t u d i e d t h e system a t temperatures between 25" and 70°C. and found only o n e liquid p h a s e over t h e range of conditions examined. They were a b l e t o demonstrate, however, t h a t two liquid p h a s e s were obtained, over most of t h e solvent composition range, when a c e t o n e or isopropyl alcohol w a s t h e organic component. T h e saturated density data recorded w a s used by T u r s i and Thompson (4) t o study t h e effect of sodium s u l f a t e on t h e vapor-liquid equilibrium of ethyl alcohol and water. d e Bruyn (1) h a s reported liquid-liquid equilibria for t h e s y s t e m ethyl alcohol-sodium sulfate-water between certain concentrations of alcohol and t h e s e d a t a a r e copied by Seidell. Schreinemakers and d e B a a t (2) l a t e r noted that d e Bruyn's d a t a w e r e metastable equilibria. Evidence t o s u g g e s t a close relationship between t h e phenomenon of two-phase formation i n raw sodium sulfonate solutions and i n solutions of sodium s u l f a t e ...

Equilibrium diagram of the water + K2SO4 or Na2SO4 + 1-propanol or 2-propanol systems at boiling conditions and 101.3 kPa

“…Their SLL equilibrium data at 353.15 K are represented in Figure 2. Mills and Smith [16] also determined liquid-liquid equilibrium data for the system with 2-propanol at 313.15 and 333.15 K. As in the systems with K2SO4, the temperatures used in the present work are higher than those but follow the trends of the previous data within the uncertainty of the measurements as can be seen in Figure . In previous works, the equilibrium diagrams of water + NaCl/KCl/NH4Cl + 1-propanol or 2propanol systems [7][8][9][10][11] were determined at boiling temperatures and 101.3 kPa. All these systems, where monovalent salts were involved, showed liquid-liquid phase splitting at the boiling point and even at lower temperatures, giving rise to ATPSs.…”

“…Therefore, the equilibrium diagrams of the water + Na2SO4/K2SO4 + 1-propanol/2-propanol systems have been determined at boiling temperatures and 101.3 kPa. No studies of the equilibrium of these four systems at boiling temperatures have been found in the literature although there are several works with equilibrium determinations at lower temperatures [12][13][14][15][16] 2. Experimental…”

Sodium iron sulfate alluaudite solid solution for Na-ion batteries: moving towards stoichiometric Na2Fe2(SO4)3

“…Therefore, the precipitation at 65 °C of an aqueous solution by isopropanol was investigated. However, in these conditions, the aqueous and organic phases are not miscible 32 and precipitation does not occur. Instead, the water in the aqueous fraction evaporates, leading to a mixture of Na 2 Fe(SO 4 ) 2 •4H 2 O and FeSO 4 •H 2 O.…”

Polyol from spent coffee grounds: Performance in a model pour-in-place rigid polyurethane foam system

“…Solubility of sodium sulfate in isopropanol-water system was reported by Mills and Smith. 16 Assuming that the SCG residue in the solid residue after neutralization (Residue #2) will generate the same amount of ash (3.8% AE 0.2%) measured for SCG residue after extraction of the liquefaction product with isopropanol (Table 1), 5.1 g of total Residue #2 weight (56.7 g) can be ascribed to sodium sulfate. The remaining amount of 51.6 g can be ascribed to the dry solid residue after liquefaction reaction that was removed with the isopropanol during the decantation process.…”