US2131308A - Production of colloidal fuel - Google Patents

Description

Sept. 27, 1938. E. BLU MNER PRODUCTION OF COLLdIDAL FUEL Filed Jan. 18, 1936 /n vento Patented Sept. 27, 1938 UNITED STATES PATENT OFFICE Application January 18, 1936, Serial No. 59,753

In Great Britain January 21, 1935 3 Claims.

This invention relates to the production of true colloidal fuel and low boiling-point hydrocarbons from solid bituminous fuels, more particularly coal, and provides a process and an apparatus for subjecting suspensions of such solid fuels in pulverized, state, in hydrocarbon oils to heat treatment under pressure, accompanied by mechanical trituration and grinding.

According to the present invention, solid bituminous fuel, such as bituminous coal, which is pulverized so as to'be capable of passing through a 150- to ZOO-mesh screen, is suspended in crude oil, fuel oilor other high-boiling hydrocarbon oils, and is then heated up to about 450 0., under a pressure exceeding atmospheres, under which treatment the bituminous constituents of the fuel undergo conversion between 270 and 400 C. This change is accompanied by the formation of gas and the evolution of steam and 20 at the same time the viscosity of the massin creases, but diminishes again as the temperature continues to rise, and finally falls to a level that is below that of the original solid fuel oil suspension.

During the performance of the process of the present invention the suspension is temporarily emulsified, the reaction products of the bitumen passing into solution in the oil and even the finest pores and channels in the residual-carbonaceous mass becoming filled with oil instead of with bitumen, thus forming a soft and readily triturable mass which, if sufficiently manipulated, assumes such a finely divided condition that a colloidal solution of carbonaceous matter fuels, such as bituminous coal, can be converted into the colloidal condition in a relatively simple manner without high working costs, an operation which cannot be economically effected by mechanical means alone, I

- A point of special importance in carrying out the present process is that the mechanical treatment of the solid fuel oil suspension-should be performed simultaneously with theprogressive conversion due to the heat treatment under pressure; firstly, in order toproduce a most intimate emulsification oi the carbonaceous substance with the oil, and secondly, to effect extreme disintegration and grinding of the residual carbonaceous skeleton to colloidal fineness, immediately after the emulsification phase.

Simple though the hereindescribed operations may seem, the ph'enonema of molecular conversion occurring during said process are, neverthe less, exceedingly complex. The reaction products in oil is bbtalned;*---By this means bituminous of the coal bitumen, for example, are not lowtemperature tars and, in any event, are comparable only with tars obtained by steam distillation in vacuo. The finely divided residual carbon dispersed in the oil is not coke, but a carbonaceous substance-containing the ash constituents, of course-which is comparable, to some extent, with the residues from the extraction of coal, though this latter process, being usually performed with-solvents of low boiling point, does not-nor can it-ever lead to the complete extraction of the bitumen.

In the final heating state of about 400 to 450 C., the solution of bitumen in oil which also contains the colloidal carbonaceous matter is subjected to a moderate cracking treatment, accompanied by continuous trituration. During this treatment, as yet unidentified molecular reac tions and migration of hydrogen between the oil and the coal hydrocarbons occur. It has been ascertained that the bituminous matter in coal for example, furnishes considerably larger yields of benzlne when treated in accordance with the present invention than when treated by itself, even when allowance is naturally made for the benzine attributable to the oil vehicle itself.

The apparatus designed for carrying out the improved process is illustrated diagrammatically and by way of example on the accompanying drawing in which Figure 1 is in its left-hand portion (larger than the right-hand half of the sheet) a vertical section through that apparatus, and in its remaining portion, in the righthand half of the sheet, a side view of certain additional members, all as fully described hereinafter, and Figure 2 is a horizontal section through a portion of one of the vertical cylinders visible in 'Fig. 1, drawn to' a considerably enlarged scale.

On the drawing, l denotes a storage vessel or receptacle for the coal-oil suspension which enters into the vessel I through a tube Ia and which is pumped by means of a high-pressure pump 2 from the vessel I and through pipes 3 and 4 into the serpentine tube 48 in the interior of a heat-exchanger 5 from which said suspension passes through a pipe 6 into a vertical cylindrical heating vessel "I. in which the suspension is heated to about 100 C. There is a plurality of such vessels (six in the example shown, viz 1a, 1b, 1c, 1d, 1e, 1:) assembled in a masonryfurnace 8 having fiues 8a. in which said vessels are located and through which heating gases, maybe furnace gases or waste gases, (for example coming from the gas tube 28s) are conducted so as to heat the said vessels to about the temperature stated. All vessels 1 are of equal construction. Each comprises, besides the vessel 1 proper, a cylindrical rotary insertion 9 filling the vessel to such an extent that only a narrow tubular passage l0 remains through which the suspension must pass. Each insertion 9 is firmly connected with an upper shaft l2 turned by any suitable means so as to rotate in turn the insertion 9.

The tubular space or-passage betweenthe stationary'vessel- I. and the rotary insertion 9 is subdivided into a plurality of parallel compartments, say six,-by vertical members ll (Fig. 2)' of about shoe-like transverse section which contact with the inner surface of the respective vessel 1 and are secured to elastic strips l3 affixed to the outer surface of the appertaining member 9. The suspension forced through the tubular passage flows now not only vertically, but is also rotated on its way through said passage,'and-ow- Between each two vessels ingto the suitablychosen shape of the members H the particles contained in-the suspension are very finely triturated.

M denotes a foot-bearing for the, rotary inser- 'tionfl; There is, of course, provided a foot bear,-

ing for every insertion, v 1 islocated in the furnace 8 a narrow cylinder I6, the upper, end of which is connected with one. of the adjacent .ve'ssels I; by means of a bent pipe l5 .by which the contents of the vessel 1a. treated therein is conducted into the second vessel (It). The cylinder I6 is notlocatedin a flue and, therefore, not

. heated by. hot gases. Thecylinder-IS receives the entire contents of the. vessel 10,, i. e. the liquid, the vapor and the .gas, which components of the suspension are separated in, the said cylinder.

In each cylinder. I6 is alongvertical float I'I connected at its .upper end with an outer automatically acting needle valve l8 regulating the height of the level in the respective cylinder, independent of the pressure in the cylinder. If the formation of gas increases and, therefore, the level of the liquid in the cylinder is pressed below a certain normal height, the float l'l opens the appertaining needle valve I8 whereupon the gas and the vapor escape into a pipe l9 through which they pass to an expansion vessel 20. When then the liquid in the cylinder l6 again rises, the float H is lifted by it and the valve I8 is closed.

It is a very important condition and a high advantage of my new process and apparatus, that there comes gas free coal-oil fluid only from one heated cylinder I to the next one over the cylinders 16 through the pipes l5 and 2i.

All cylinders it are connected up in parallel to the vessel 20, but the vessels 1 l-'11) are connected up in series, and the last of these vessels (1:) is connected with the vessel 20 by the intermediary of the last cylinder l6 and by a pipe 22 extending into the vessel 20 from below to about into the middle portion of saidvessel where it is attached-to a so-called' expansion colloidal mill comprising a stationary disk 23 firmly connected with the pipe 22, and a rotary disk 24 connected with a vertical shaft 25 by which it is "mate's.

The two disks are polished and are made of a specially selected kind of steel. The shaft 25 is provided with a weight 26 so as to exert a corresponding pressure upon the shaft 25, or upon the two disks 23 and 24 and the composition entering between them and being acted on between them. The object of said weight is mainly to maintain the pressure in the system, or to regulate the pressure exerted by the pump 2. The supply of heatto the heatingchambers in 'the masonry-furnace 8 is soregulated that the highest heat is in the first flue (8s) and the lowest temperature is in the last flue containing the vessel Ii. Owing to a certain reduction of pressure in the mill 23, 24 another fall of temperature takes place in the chamber or vessel 20, the final temperature of the product being about 260 C.,

.whereas the-initialtemperature had amounted to 450 C.

Allhydrocarbons evaporating below 260 C. distill through the pipe 21 into the fractional distillation column 2,8. The benzines are withdrawn through .the pipe 29 and are condensed in the condenser 30, wherefromthe condensed benzine is conducted through the pipe 3| into a separator 32 in whichwater and] gas are separated from the benzine, and from which the benzine flows through the tube 32b to a not shown ben'zine storage vessel and the water is conducted away throughthe tube 321:, as indicated. The. gasti'1be 32a is connected with the gas-tube 28a. of the distillation column 28 of the plant.

The hot, true colloidal fuel collecting on the bottom of, the vessel 20 passes through a pipe 33 into the heat-exchanger 5 containing the serpentine tube lit-and flows from the heat-exchanger 5,

comprising pulverizing-solid bituminous fuel and mixing the same with high-boiling hydrocarbon oil to provide a suspension, successively subjecting the suspension to heat and pressure whileimparting a whirling motion thereto and alternately cooling the suspension, the'steps of heating being at progressively reducedtemperatures and gas and steam being withdrawn during each cooling step, and then allowing the suspension to expand and grinding the treated suspension and removing the remaining gas to form a true colloidal fuel of the residue.

3. The process set forth in claim 2 wherein the suspension is subjected to trituration during the whirling motion as it is successively heated.

ERWm BLiiMnER.

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