Hot water separation

The hot-water separation process involves extremely compHcated surface chemistry with interfaces among various combinations of soUds (including both silica sand and alurninosilicate clays), water, bitumen, and air. The control of pH is critical. The preferred range is 8.0—8.5, achievable by use of any of the monovalent bases. Polyvalent cations must be excluded because they tend to flocculate clays and thus raise viscosity of the middlings in the separation cell. 

Monosaccharides are probably involved in the browning reactions that occur during the roasting of coffee. Caramelization involving the sugars alone, and Maillard reactions, between sugars and free amino acids, produce polymeric yellow to dark brown substances, known as melanoidins. These melanoidins can be extracted into hot water, separated and characterized.105... 

There have been at least 13 distinguishable efforts to develop a workable hot water separation process. These ranged in capacity (Table II) from small batch units to fairly substantial pilot plants, and culminated in the operation of a 45,000 bbl/day commercial plant. 

When bituminous sand is mixed and heated with water into a mortar-like pulp, the oil is dispersed into small oil flecks which lie unattached among the sand grains. The content of clayey material in bituminous sand plays an important role in fleck formation and fleck formation plays an important role in the hot water separation process. In the rare cases of bituminous sands containing practically no clay, the separation process proceeds unsatisfactorily. 

In an autoclave of 1-liter capacity, without stirrer, and heated by an oil bath, is placed 600 cc. dry methyl alcohol in which 23 grams of metallic sodium has previously been dissolved (reflux condenser), and to this is added 158 grams of pure o-nitrochlorobenzene (m.p. about 32°C. b.p. 243°). The autoclave is sealed and the heating is started. The temperature is raised to 120° over a period of 1 hour, held at this point for 3 hours, and finally held at 128° for 1 hour more. The pressure is 8 to 10 atmospheres. At the end of the reaction, the methyl alcohol is blown out through the valve into a good condenser. The recovered methyl alcohol can be used without purification in a subsequent run. The reaction product is removed from the autoclave, washing the latter out with hot water to remove the sodium chloride. The crude product is washed twice with five times its volume of hot water, separated, and distilled in vacuum. The yield is 136 grams, or 88 per cent of the theoretical amount. The product boils at 141° at 15 mm. 

One of the greatest problems that has emerged from tar sand resource development is the disposal (and control) of the tailings streams that arise from the hot-water separation. The extent of this problem had not been appreciated until the commercialization of the tar sands commenced. 

Usually isolated as the sulfate B-2HjSO white powder, [u — 85.49" (said aq soln). One gram dissolves in 80 ml water at room temp. Freely sol in hot water, separates from the supersatd soln on cooling as a clear, colorless oil contg 50% HjO. n 1.4435. Clupeine is split by protaminase, ac-... 

Pasternack, D.S. Clark, K.A. The components of the bitumen in Athabasca bitumous sand and their signification in the hot water separation process, Alberta Research Council Report, 1951, No. 58,1-14. 

With Th a saturated solution of K2SO4 forms an insoluble doirble salt that is not affected by an excess of the reagent but is dissolved by hot water (separation from the yttroids). The corresponding sodittm and ammoniirm double salts are soluble in water and in S04 (distinction from the ceroids), and Th(S04>2, Th(S04)3 and Th(S04)4 are known. The 0.03 tuM solubility of /2K2S04 Th(804)2 in 3.5 dM K2SO4 separates it from the soluble Ln sulfates. 

Add 5 g. of potassium hydrogen tartrate and 5 g. of antimony trioxide (each being finely powdered) to 30 ml. of water contained in a small flask, and boil the mixture under a reflux water-condenser for 15 minutes. Then filter hot, using a Buchner funnel and flask which have been preheated by the filtration of some boiling distilled water. Pour the clear filtrate into a beaker and allow to cool. Potassium antimonyl tartrate separates as colourless crystals. Filter, drain and dry. Yield, 5 g. The product can be recrystallised from hot water, but this is usually not necessary. 

Place I g. of benzamide and 15 ml. of 10% aqueous sodium hydroxide solution in a 100 ml. conical flask fitted with a reflux water-condenser, and boil the mixture gently for 30 minutes, during which period ammonia is freely evolved. Now cool the solution in ice-water, and add concentrated hydrochloric acid until the mixture is strongly acid. Benzoic acid immediately separates. Allow the mixture to stand in the ice-water for a few minutes, and then filter off the benzoic add at the pump, wash with cold water, and drain. Recrystallise from hot water. The benzoic acid is obtained as colourless crystals, m.p. 121°, almost insoluble in cold water yield, o 8 g. (almost theoretical). Confirm the identity of the benzoic acid by the tests given on p. 347. 

When the ij hours boiling is complete, preheat a Buchner funnel and flask by pouring some boiling water through the funnel with the filter-paper already in position, and then quickly filter the boiling solution. Transfer the filtrate to a beaker to cool, and then wash the insoluble residue of diphenylurea on the filter twice with hot water, and drain thoroughly. Cool the filtrate in ice-water the monophenylurea separates as colourless needles. Filter at the pump and drain well. Recrystallise the crude product from boiling water, as in the previous preparation. Yield of monophenylurea, 2 5-3 g. m.p. 147°. 

To obtain the free acid, dissolve the potassium salt in 50 ml. of cold water, filter the solution if a small undissolved residue remains, and then boil the clear solution gently whilst dilute sulphuric acid is added until the separation of the acid is complete. Cool the solution and filter off the pale orange-coloured crystals of the benzilic acid wash the crystals on the filter with some hot distilled water, drain well, and then dry in a desiccator. Yield of crude acid, 4 g. Recrystallise from benzene (about 50 ml.) to which a small quantity of animal charcoal has been added, filtering the boiling solution through a preheated funnel fitted w ith a fluted filter-paper, as the benzilic acid readily crystallises as the solution cools alternatively, recrystallise from much hot water. The benzilic acid is obtained as colourless crystals, m.p. 150°. 

Use. If the substance under investigation is soluble in water, dissolve about 0 1 g. in 1-2 ml. of water, and add 5-10 ml. of Reagent A. On shaking for a few minutes, with scratching if necessary, the yellowish-orange hydrazone will usually separate if this does not occur, warm the solution gently in a hot water-bath for 5-10 minutes. 

Dissolve 13 g. of sodium in 30 ml. of absolute ethanol in a 250 ml. flask carrying a reflux condenser, then add 10 g. (9 5 ml.) of redistilled ethyl malonate, and place the flask on a boiling water-bath. Without delay, add a solution of 5 3 g. of thiourea in a minimum of boiling absolute ethanol (about 100 ml.). The sodium salt of thiobarbituric acid rapidly begins to separate. Fit the water-condenser with a calcium chloride guard-tube (Fig. 61, p. 105), and boil the mixture on the water-bath for 1 hour. Cool the mixture, filter off the sodium salt at the pump and wash it with a small quantity of cold acetone. Dissolve the salt in warm water and liberate the acid by the addition of 30 ml. of concentrated hydrochloric acid diluted with 30 ml. of water. Cool the mixture, filter off the thiobarbituric acid, and recrystallise it from hot water. Colourless crystals, m.p. 245 with decomposition (immersed at 230°). Yield, 3 5 -4 0 g. 

Example. Dissolve 0 3 g. of benzoic acid in a minimum of hot water (about 70 ml.) and add 5% aqueous sodium hydro.xide until the solution is just alkaline to methyl-orange, then add i drop of dilute hydrochloric acid. Pour this solution of the sodium salt into a solution of 0 5 g, of benzylthiouronium chloride in 5 ml. of water, and cool the stirred mixture in ice-water. Filter off the benzylthiouronium salt which has separated, and recrystallise from ethanol con taining 10% of water cream-coloured cr> stals, m.p. i66 . (M.ps., pp. 543 545.)... 

Dissolve or suspend 0 - 5 g. of the acid in 5 ml. of water in a small conical flask, add a drop or two of phenolphthalein indicator, and then 4-5 per cent, sodium hydroxide solution until the acid is just neutrahsed. Add a few drops of very dilute hydrochloric acid so that the final solution is faintly acid (litmus).f Introduce 0-5 g. of p-bromophenacyl bromide (m.p. 109°) dissolved in 5 ml. of rectified (or methylated) spirit, and heat the mixture under reflux for 1 hour if the mixture is not homogeneous at the boiling point or a solid separates out, add just sufficient alcohol to produce homogeneity. [Di- and tri-basic acids require proportionately larger amounts of the reagent and longer refluxing periods.] Allow the solution to cool, filter the separated crystals at the pump, wash with a little alcohol and then with water. Recrystallise from dilute alcohol dissolve the solid in hot alcohol, add hot water until a turbidity just results, clear the latter with a few drops of alcohol, and allow to cool. Acetone may sometimes be employed for recrystallisation. 

Dissolve 2 drops of concentrated sulphuric acid in 2 ml. of the ester and add 1 - 5 g. of 3 5-dinitrobenzoic acid. If the b.p. of the ester is below 150°, refiux the mixture gently if the b.p. is above 150° heat the mixture, with frequent shaking at first, in an oil bath at about 150°. If the 3 5-dinitrobenzoic acid dissolves within 15 minutes, heat the mixture for 30 minutes, otherwise 60 minutes heating is required. Allow the reaction mixture to cool, dissolve it in 25 ml. of ether, and extract thoroughly with 5 per cent, sodium carbonate solution (ca. 25 ml.). Wash the ethereal solution with water, and remove the ether. Dissolve the residue (which is usually an oil) in 5 ml. of hot alcohol, add hot water cautiously until the 3 5-dinitrobenzoate commences to separate, cool and stir. Recrystallise the derivative from dilute alcohol the yield is... 

Place 125 ml. of concentrated ammonia solution (sp. gr. 0-88) in a 600 ml. beaker and surround the latter with crushed ice. Stir the ammonia solution mechanically, and introduce the n-caproyl chloride slowly by means of a suitably supported separatory funnel with bent stem. The rate of addition must be adjusted so that no white fumes are lost. The amide separates immediately. Allow to stand in the ice water for 15 minutes after all the acid chloride has been introduced. Filter oflF the amide at the pump use the flltrate to assist the transfer of any amide remaining in the beaker to the Alter (2). Spread the amide on sheets of Alter or drying paper to dry in the air. The crude n-capro-amide (30 g.) has m.p. 98-99° and is sufficiently pure for conversion into the nitrile (Section 111,112) (3). Recrystallise a small quantity of the amide by dissolving it in the minimum volume of hot water and allowing the solution to cool dry on filter paper in the air. Pure n-caproamide has m.p. 100°. 

Place 50 g. of ammonium thiocyanate in a small round-bottomed flask and immerse a thermometer in the substance. Heat in an oil bath until the temperature rises to 170° and maintain it at this temperature for 1 hour. Allow the melt to cool and extract it with 60-70 ml. of hot water. Filter the solution and allow to cool when crude thiourea separates the unchanged ammonium thiocyanate remains in the solution. Filter ofiF the crude product and recrystallise it from a little hot water. The yield of thiourea, m.p. 172°, is 8 g. 

The sulphonanilldes may be prepared by either of the following methods —(i) Reflux the solution of the sulphonyl chloride in benzene obtained as above, with 2 5 g. of aniline for 1 hour. Concentrate the benzene solution to half its volume and cool in ice. Collect the solid which separates on a filter, wash with hot water, and recrystallise from ethanol or dilute ethanol. 

---