US1437775A - Extraction of fusible combustibles such as montan wax - Google Patents

Description

Patented Dec. 5, 1922.

MTE 'sma'rasv 1,431,715 PATENT OFFICE.

HERMANN PLAUSO IL-OF HAMBURG, GERMANY.

EXTRACTION or FUSIBLE coMBUs'rIBLns soon as mourn wax.

Ho Drawing.

To all whom it may concern:

Be it known that I, HERMANN PLAUsoN, Esthonian subject, residing at Hamburg,

Germany, have invented certain new and useful Improvements in Extraction of Fusible Combustibles Such as Montan Wax, of which the following is a specification.

Hitherto a wax which will be termed Montan wax for brevity has been obtained by extraction from bituminous browncoal or lignite by treating the crude coal as it comes ,='from1 the mine, a 'fiter preliminary drying to a water contentof 10 to with organic bitumen-solvent hydrocarbons or derivatives such as pyridine, benzene, benzine or the like with oriwithout pressure,

and the solution has been concentrated by distillation of the solvent.

This process requires the use of large quantities of benzene or other organic solvent with consequent great danger of fire and the process is expensive on account of the high cost of the solvent, especially 1n view of the 5 to 10% loss which occurs through its volatility.

Experiments to extract moist bituminous coal direct have been unsuccessful in practice since the losses of organic solvent have been still greater. v

The presentinvention provides-a process on new lines in which the extraction can be performed either without organic solvents at all or using onlyvery small quan-,

to 10% of caustic alkali, lysalbinic or: protalbinic acid or alkali protein compounds, etc.,.or solvents such, as benzene, benzine, pyridine, acetone, alcohol, etc., the whole of the bituminous constituents can be emulsified. Such treatment is preferably effected in a high speed disintegrator of the type having beater arms which rotate at a peripheral velocity of 2000 metres per minute, for example the colloid mill dGSCI'ibBdslIl my co-pending application, Serial No. 437,117, filed Jan. 13th, 1921 (Case 14).

It has Application filed January 13, 1921. Serial No. 437,121.

further been demonstrated that such emul-.

sions obtained by dispersion or more correctly the bitumen articles occurring there inin the dispersed state, can be separated from coarse sand and coal by direct filtration. The pure dispersion containing no coarse precipitate can then be treated with small quantities of electrolyte such as salts or acids and allowed to stand in suitable high towers for the purpose of sedimentation.

. It has been-found by observation that the colloidal bitumen then completely deposits leaving an upper clear layer of water containing all the water-soluble constituents,

when the water can be separated by decantation or in other known ways from the lower paste containing Montari wax; if large quantities of salt are present in the water they can be recovered by evaporation.

The thick bituminous mud can be worked up into Montan wax in several ways (a) v By the addition of 10 to 30% of sol-e "vent for Montan wax and heating to 110 to 130 C when two layers are formed, of which the upper layer consists of Montan wax and solvent, having a specific gravity lighter than the water containing the coal. (b) By distillation of the wet mud pref-v erably in high vacuo with superheated vapours of hydrocarbons aloneand/or with superheated steam.

" (a) By salting out the Montan wax with concentrated salt solutions or electrolytes of the highest possible specific gravity.

It has hitherto been proposed to extract Montan wax from coal :by treatment an steam or by extraction. In the steam proc-fi v ess the so-called sulphur coal is' coked by superheated steam at 250 C. with fairly heavy firing. y

.According to the present invention, however, tlfese steps are employed in combi nation with the novel emulsification or dispersion stepwhich is essential for the purpose bf the invention. No coking takes place but the separation of the bitumen from the coal depends on the novel discovery that it is possible to emulsify or disperse the mixture which is a quite unexpected result. The

the disadvantage that the coal must be first dried when it is treated with benzine, solar oil, etc. Extraction with benzine has the disadvantage of danger from fire and loss of solvent. According to the present 'procextraction process hitherto employed has Y ess, the result is obtained by treatment direct 'with water or by using small quantities of tion as regards the danger of fire, there is a saving in that preliminary drying is unnecessary, and there is no heavy expenditure involved in using expensive solvents 'so that considerable advantages are attained for the extraction of Montan wax from bituminous brown coal.

It has been proposed hitherto to distil crude brown coal bitumen heated to 300 C.

with steam superheated to 250 C. Such a distillate was decolourized and converted into purified Montan wax by using organic solvents. Distillation in the present process is however employed as a step following the novel emulsification or dispersion and the present invention further provides novel methods of distillation, e.- g., the use of superheated vapours "of organic solvents. The distillation step as applied according to the present invention is preferably employed with superheated hydrocarbon vapours either alone or mixed with superheated steam. Vacuum can be employe In this way the distillation "temperature is lowered so that decomposition of the wax is prevented. This process yields apure Montan wax which has hitherto been impossible by distillation processes.

Example. 20 parts of bituminous brown coal in the moist state as obtained from the mine are preliminarily ground in a mill or kollerang and then diluted with ,100 parts of water and continuously disintegrated in a high speed disintegrator which is preferably connected by a pump with a steam-heated agitating vessel placed over the disintegratior so that the pump causes a continuous circulation from the disintegrator to the heated reservoir from which the liquid, flows by gravity into the disintegrator again. Durmg this time the mixture is heated directly or indirectly through the vapourjacket of the agitating vessel to 90 to 110 C.

Dlsmtegration is continued for instance for from one half to 3 hours, depending on the type of coal and the construction of the" drsmtegrator, till a sample shows that a disperse suspension has been obtained and only coarse parts such as sand separate out.

yThe aqueous mixture of the dispersed brown coal and the crude Montan wax emulsified ;by hot water is filtered by a suitable filter ress with coarse filter cloth. 'The crude the cloth.

The filtered emulsion of brown coal and bitumen is allowed to stand quietly in the heated state in large vessels for several hours so that the whole of the finely dispersed colloidal substances separate out. By weak acidification, e. g., with 0.1 to 3% of a. strong acid, the time of settling can be considerably shortened and a completely clear water solution then remains. This is drawn off and the muddy part is filtered as well as possible so that the water soluble acid salts are removed.

The residual thick mud can now be-worked up to crude Montan wax in various ways as follows 2- (1) 10 to 30% of Montan wax solvent is added to the mud and the mixture is heated in an autoclave to 110 to 130 C. and allowed to cool slowly. On opening, two layers are observed of which the upper consists of crude Montan wax and the organic solvents and the lower of wet dispersed coal of almost molecular fineness. This can be used as a colouring matter after washing and drying or can be worked up into briquettes-for instance by adding sulphite cellulose liquor and compressing.

There is about 15 to'20% of the finest brown coal present in the upper layer consisting of. crude Montan wax and the solther quantities of solvent, the crude Montan wax is completely freed from this brown coal by filtration. Suitable solvents for the purpose are benzene and its homologues, benzine, aniline, quinoline, alcohols, acetone and the chlorinated hydrocarbons or mixtures of these liquids.

(2) The filtered concentrated dispersed bitumen brown coal mud can be treated to separate the Montanwax from the brown coal by filtering off or othewise separating the water and distilling the solids in superheated vapours of a solvent such as petroleum, aniline, toluene, xylene or benzene especially in vacuo. Such a distillation not only separatesthe crude Montan wax from the coal, but also effects a refining. After driving ofi the distillation liquid, the product is light yellow, very pure and possesses a melting point between 85 and 87 C. The distillation can also be performed by using the aniline, petroleum, or xylene Vapour with superheated steam. This effects a good transference of heat to the hydrocarbon used for distillation and by using an organic solvent for the Montan wax, its separation from coal and dirt is facilitated while the distillacoal and bitumen mud with twice to five times its amount of neutral salt solution as concentrated as possible in suitable vessels for some time (3 to 24 or more hours) to 110 to 130 C. preferably under pressure. This salts out or separates out the crude Montan wax which collects on the surface. The liquid is now allowed to cool quietly. An uppfr layer of more or less thick crust of crude ontan wax is formed, a middle layer of aqueous salt solution and fine coal mud separates on the bottom. If 1 to 3% of a hydrocarbon solvent for Montan wax is added to the salt solution the period of salting out can be' considerably shortened.

Instead of salting out the bitumen mud with aqueous salt solution, the same effect can be obtained by heating with those organic substances which are solvents for Montan wax when hot, for instance naphthalene or the like.

The manufacture of emulsions of dispersed coal and crude Montan wax by means of water can be considerably assisted and accelerated by the addition of dispersion accelerators such as alkali, soaps and decomposition or intermediate products of proteins, provided that these do not coagulate on heating. Or gluton and its decomposition or intermediate products can be added or sugar in small quantities from 0.1 to 3%; this also reduces the temperature necessary for heating.

Although the use of these substances has been proposed for the manufacture of colloidal solutions of various kinds it could not have been foreseen that they would be useful for transforming the brown coal intothe disperse state and simultaneously emulsifying crude Montan wax since many substances are present in brown coal which might be expected to oppose dispersion.

The dispersion is also accelerated if 1 to 5% of a solvent for Montan wax is added tothe emulsifying liquid before disintegration. It could not have been foreseen that such small quantities of solvent would accelerate the dispersion of brown coal and the emulsion of the Montan wax since it is known that such hydrocarbons usually lose their solvent power by emulsification with water. 'In .some cases it has been possible to separate out the crude Montan wax di rect if after treatment with water so much neutral salt is added that a concentrated salt solution is .formed and then by heating -to the boiling point of the salt solution,

the Montan wax is separated out and filtered. Obviously this operation can be performed direct with such salt solutions.

It was not known and it could not'have been foreseen that crude Montan wax or in some cases relatively pure Montan wax could be obtained from bituminous .substances b water or aqueous emulsion with hydrocar ons. Important features of the invention are the emulsification wor dispersion of the raw materials by disintegration with hot water with or without the addition of acceleratingagents so as to obtain a finely dispersed product from which the emulsified Montan wax can be salted out by heating with concentrated salt solutions or solvents or recovered by direct distillation with superheated hydrocarbon vapours alone or mixed with steam and/or in vacuo.

i The same results have not been obtained by directly treating the brown coal with water without conversion into the highly dispersed state.

While the invention has been described with reference to the treatment of bituminous coal to yield a product which has been termed Montan wax, it will be clear that the broad features of the invention are applicable to the extraction of bituminous or waxy bodies from any suitable raw material such as bitumen from bituminous coal or waxy materials from shales.

I declare that what I claim is -1. Process for extracting Montan wax from bituminous earthy material which in 4. Process of treating bituminous brownv coal which includes the step of preparing an emulsion of the Montan wax contained therein with water. I

5. Process of treating bituminous brown coal which includes the step of preparing an emulsion of the Montan wax contained therein with water in presence of smallquantities of an emulsifying agent.-

6. Process of treating bituminous brown coal which includes the step of preparing an emulsion of the Montan wax contained therein with water in presence of small coal which includes the step of preparing an emulsion of the Montan wax contained therein with water and treating the emulsion with a Wax solvent.

11. Process of treating bituminous brown coal which includes the step of preparing an emulsion of the Montan wax contained therein with water and distilling the wax in a current of superheated solvent v'apour.

12. Process of treating bituminous brown coal which includes the step of preparing an emulsion of the Montan Wax contained therein with Water and distilling the wax in a current of superheated solvent vapour and superheated steam.

13. Process of treating bituminous brown coal which includes the step of preparing