Chemical Papers 65 (6) 805–812 (2011) DOI: 10.2478/s11696-011-0077-3 ORIGINAL PAPER Extraction of phytosterols from tall oil soap using selected organic solvents a Milena Rousková*, a Aleš Heyberger, b Jan Tříska, c Miroslav Krtička a Institute of Chemical Process Fundamentals of the Academy of Sciences of the Czech Republic, v.v.i., Rozvojová 2/135, 165 02 Prague 6, Czech Republic b Global Change Research Centre of the Academy of Sciences of the Czech Republic, v.v.i., Branišovská 31, 370 05 České Budějovice, Czech Republic c Technology park Chomutov, Cihlářská 4132, 430 03 Chomutov, Czech Republic Received 8 March 2011; Revised 24 June 2011; Accepted 29 June 2011 Tall oil soap as a waste product of the sulphate cellulose production process was treated by single-stage liquid–liquid extraction. The aim of this study was to compare yields of health beneﬁ- cial matters contained in tall oil soap when several extraction solvents, recommended in literature, were used. Hexane, 1-methyl-4-(1-methylethenyl)-cyclohexene, 2-methylpropan-1-ol, hexan-1-ol, 4- methylpentan-2-one, 2-methoxy-2-methylpropane, and butyl ethanoate were tested. For hydrocar- bons it was necessary to add a de-emulsiﬁer into the system, which limits the formation of foams and stable emulsions. The highest yields of total phytosterols (78 %) and especially of β-sitosterol (100 %) were reached when butyl ethanoate was used. However, it was necessary to adjust pH of the treated raw material to approximately 7. The highest yields for feed where pH was not adjusted were obtained with 2-methylpropan-1-ol: 67 % of total sterols and 89 % of β-sitosterol. Disadvan- tages of most of the tested solvents included the formation of the undesirable solid interphase which could not be removed, partial solubility of the solvents in the water phase, their high boiling point and/or instability. These disadvantages prevent the use of these solvents in industrial applications; they also complicate the treatment of tall oil soap by liquid–liquid extraction or the regeneration of the used organic solvent. c  2011 Institute of Chemistry, Slovak Academy of Sciences Keywords: liquid–liquid extraction, tall oil soap, phytosterols, β-sitosterol Introduction Source, composition, and utilisation of tall oil soap Tall oil soap (TOS) is the side product of the sulphate (kraft) process of pulp production which is based on the digestion of chips of diﬀerent types of soft and/or hard wood by boiling at high tempera- tures in an aqueous solution with sodium hydroxide and sodium sulphide at high pH (13–14). A dark wa- ter suspension (black liquor) is formed. From this so- lution, cellulose ﬁbres, which are the main raw ma- terial for the production of pulp and paper, are sep- arated. The remaining black liquor contains approx- imately 15 % of dissolved compounds, and it is sub- sequently concentrated by multistage evaporation. At the concentration, solid part is separated by its skim- ming from the surface of the liquid black liquor and is further processed. This product is called crude TOS. Its composition depends on the ratio and type of the processed wooden mass (Auhorn & Niemelä, 2006). It contains in average 30–50 % of water, 20–60 % of soaps, fatty and/or resin acids, 5–30 % of unsaponiﬁ- *Corresponding author, e-mail: rouskova@icpf.cas.cz Unauthenticated Download Date | 5/9/16 10:30 AM