US1484258A - Process for the treatment of coal - Google Patents

Description

Feb. 19, 1924. 1,484,258

Y J. T. FENTON I PROCESS FOR THE TREATMENT COAL Filed'Aug. 24. 1922 2 Sheeps-Sheet 1 Nor-ma. l

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UNITED STATES PATENT-l OFFICE,

JAMES T. FENTON, F SALT-LAKE CITY, UTAH.

PROCESS FOR THE TREATMENT OF COAL.

Application filed August 24, 1922. Serial No. 584,040.

To all whom it may concern:

Be it known that I, JAMES T. FE NTON, a citizen of the United States, and resident of Salt Lake City, in the county of Salt Lakeand State of Utah, have invented certain I new and useful Improvements in a Process for the Treatment of Goal, of which the following is a specification.

My invention relates to an easy and simple method for extracting from coal the valuable volatile constituents and gaseous the higher pitch volatiles which are normally consumed in combustion. It may be termed a long flame coke or synthetic anthracite.

In many methods of producing coke, gas, and by-products of distillation, the coal is either partially consumed or is subjected to a high heat while in retorts. Such processes involve combustion and are sometimes termed destructive distillation. v

The process forming the subject matter of my invention is entirely difierent in that the coal is subjected to a treatment in a retort with superheated steam of atemperature up to 1200 F. and at a pressure that may vary from five to five hundred pounds according to the circumstances and the results desired.

This process does not involve any combustion and may therefore be termed a noncombustive distillation process. Since it is possible that the steam is not entirely inert, it might be called a hydrolytic process. It may rather be termed an absorption distillation process since the superheated steam carries over the products of distillation by holding them in suspension. There is no chemical combination between the steam and products of distillation as there is in some types of vapor pressure distillation nor is there any breaking down of the su erheatcd steam as in the common metlio of producing water gas. v

It is desired primarily to distill the substances of the lighter volatile groups, such as the anthracene group, the naphthalene group, the carbolic group (G H group. It is found that it is possible by this method to. distill ofi? "frac-' tions having a boiling point considerably higher than the temperature of the steam employed. For example laboratory experiments have shown that aniline oil which has a boiling point of about361 F. can be produced by distillation with steam of about 216 F., and similarly with higher fractions.

It also results thatthe products of distillationcondense in a purer form than under other methods, and both the liquids and gases produced are ready for use with little or no purification.

The process is adapted for all kinds of coal andeven for the treatment of oil; shales or sands, or any substance from which similar substances can be distilled.

Other objects and features of the invention will be set forth in the following detailed description and the appended claims.

Although the process is independent of any specific apparatus, I have illustrated two forms of apparatus in a diagrammatic manner by which the process may be carried out. In one case the operation is intermittent and in the other continuous. The

and the benzene intermittent apparatus here shown is a part of that disclosed in my application Serial No. 584,038 filed August 24:, 1922 while the continuous apparatus is a part of that disclosed in my application Serial No. 584,039 filed August 24, 1922.

In the drawings:

Figure 1 is a general view of the intermittcnt apparatus, which is shown to a considerable extent in a diagrammatic manner.

{Figure 2 is a similar view of the continuous apparatus.

The apparatus shown in Figure 1 is termed intermittent because a retort, is filled with coal, subjected to treatment with superheated steam for a certain len h of tune and then emptied. Usually two identical retorts are used and are charged alternately, so that while the operation of each retort is intermittent, the production is continuous.

The retorts may be preheated if desired, but all of the heat for the distillation is derived from the superheated steam.

Referring to Figure .1 preferably built up of sections 2, 3, 4, 5 and 6 suitably fastened together. The section 3 may be repeated as desired according to the size of the retort. The sections 4 have proa retort 1 is shown,

jecting flanges that rest on supports 7 while closed. Pivoted at 17 circumferential the section 2 is provided with a closure 8 for the intake opening.

is also provided which may be closed in any desired manner. The lower section 6 has a closure 13 hinged there-to at 14 and having at its opposite side fastening means 15 by which the closure may be held tightly to the closure is a plate 16 upon which the charge of coal may rest and which can swing relatively to the closure when the latter is swung open, so

that the product of the treatment may be readily dumped. Any desired form of carrier may be employed to take away the charge after its removal from the retort, either screw or scraper conveyors, or any other suitable mechanism.

Communicating with the steam passageway 10 is a pipe 18' to which is connected the normal steam line 19 controlled by a valve 21 and the superheated steam line 20 controlled by a valve 22. Communicating with the section 9 is a pipe 23 leading to the atmosphere and also connecting to an auxiliary vapor pipe 26. This pipe is provided with valves 24 and 25, the former controlling communication" with the air and the latter controlling communication with the auxiliary vapor line 26. Also connected to the extension 9 is the main vapor pipe 27 controlled by a valve 28.

The main vapor pipe communicates with successive separators 29, 30 and 31, and

finally with the condenser header 32. The

sections of thisvapor pipe are of gradually increasing size as shown at 33, 34, and As set forth above the purpose of this is to make use of the principle of adiabatic expansion and by allowing the vapors to expand permit the temperature and pressure to be reduced proportionally. For example if the pipe sections from exit of retort to the header vary in area in about the ratio 9, 15, 28 and 38, it will result that vapors leaving the retort at a temperature of 800 and 20 pounds pressure will have a temperature 362 and 'a pressure of. 5 pounds when they reach the condenser header. This permits automatic separation 'of the products of distillation in the separators and gives distillates that require but little purification, if any.

While these ratios are found to give excellent results, it is to be understood that tain. In some cases it may be found that pipes of the same size are preferable, or even the. later sections might be smaller than the first. The pipesup-plying superheated steam to the retort ispreferably larger than the outlet relation is not essential.

The" auxiliary vapor pipe 26 has branches that communicate with andthe condenser header-32 which branches are controlled by valve 36, 37 and 38 respectively. The normal steam line 19 has a branch 39 communicating with the main vapor line and controlled by a valve 40, while the superheated steam line has a branch 41 communicating with the main vapor line at the oint shown and controlled by a valve 42. 1 thermostat 43 located at the entrance of the auxiliary vapor line 26 to the condenser 32 controls both of the pipe, although this valves 40 and 42. If these valves are both' normally closedand the temperature at the condenser header 32 becomes too low, the thermostat opens the valve 42 and permits superheated steam to pass into the main vapor line. On the contrary, if the temperature is too high, the thermostat will .open the valve 10 and permit a supply of normal steam to the lowering the temperature.

From the condenser header the gases pass through a condenser coil 44 in a water filled container 45, said coil being provided with a drain pipe 46. From the coil a pipe 47 fitted with a back pressure valve 48 leads the gas to the washers or to an further treatment that it may need.

Each separator is provided with -a plate 49 dividin the passagewa intotwo parts and providing a bafile against which the incoming vapors impinge and around which they must pass. This facilitates centrifugal fractions.

the sections 34, 35'

main vapor line, thus' Each separator has valve controlled communication 50 with a float controlled valve trap 51 in which there must be at all times a sealing level of spirits. Since the whole, system is under pressure, the outlet of spirits must be controlled by'some means which will maintain a seal and allow only suflicient liquid to leave the system unaffected by pressure or anything except the level of the liquid itself.' Each float tank should preferably be rovided with a valved drain pipe (not sliown) for the purpose of sampling the contents when desired.

In connection with the above described'apparatus, I find it advisable to employ a secondary cracking system. Pipes 52 leading from the float tanks 'connect to a common pipe 53 which conducts the liquids to a a pressure relief branch 60 equipped with apressure relief valve 61 and communicating with the storage tank 54. The main line 59 is provided at its end with a spray jet 62 which forces the liquids in a fine spray into the superheated steam line near its connection to the retort. This secondary cracking system is only brought into operation when the retort has been raised to full working temperature and the secondary treatment causes a very considerable cracking or breaking up of the molecular structures of the oils to form more spirits of the motor spirit type and more rich gas.

If desired the separator 29 may be disconnected from this secondary cracking system and the spirits produced in this stage may be used for fuel purposes under the boilers and super-heaters, since there is no particular need for further cracking of this fraction. Also, if desired the secondary cracking system may be dispensed with entirely, and the liquids from the various separators can be led into suitable receptacles for whatever further treatment or use may be found desirable. I

The operation of the device as thus far described is as follows. The retort is filled with coal to the working level and then closed. The valves 24 and 25 are open and the normalsteam line valve 21 is opened to permit the steam to drive out the air that may be present in the coal and also slightly preheat the coal. Then the superheated steam valve 22 is slightly opened Q and shortl thereafter the air valve- 24 is closed and the main steam line valve fully opened, allowing the temperature to reach the true working temperature, and at the same time the valve 25 is closed and the 7 main vapor line valve 28 is opened.

The superheated steam with all of the vapors and products of distillation now pass through the three expansive stages and through the three separators 29, 30 and 31, with an increase in volume and consequent decrease in temperature and pressure as explained previously. Preferably a thermostat 43 is placed in the condenser header at the point where the line controlled by the valve 38 enters, and this thermostat controls the valves 40 and 42 in the normal and superheated steam lines to regulate the temperature as explained above. In this manner, the end boiling point of whatever spirit it is desired to collect through the water cooled condenser system may be determined. i

'The gases after leaving the water cooled con-denser can be made to pass through another separator (not shown) if desired, such as those shown, for the purpose of removing any oil or water particles contained therein. After this, the gas passes through the relief valve, and istreated in any usual or desired fashion to fit it for use. By treatment With cold Water the ammonium may be absorbed and extracted.

The liquids leaving the separators pass .into the storage tank and are ultimately.

sprayed into the main or superheated steam line as above explained. A further cracking and the extraction of a eater percentage of distillates results. When the run ofthe retort is finished, and all of the desired volatile constituents have been removed, the superheated steam valve is partly closed and the normal steamline valve is partly opened until the temperature of the coal is reduced to about 450 F. when the bottom door is opened and the coal allowed to drop out, whereupon it may be conveyed away by worm or belt conveyors or in any other desired manner. This temperature of 450 F.

is below the temperature of spontaneous combustion, and it ,is desirable to keep the .retort at a fairly high temperature if possible. Furthermore a small amount of normal steam should be kept blowing through the retort, and both top and bottom doors.

should not be open at the same time.

In the continuous system of apparatus the coal is fed into a retort by suitable conveyors and after treatment is removed from the retort by similar conveyors The length of time consumed in the treatment may be varied as desired or as is found necessary for proper results.

In Figure 2 are shown two preheating conveyors 63 and 64 of the worm type, although a drag conveyor may be substituted for either or both, or a single conveyor may be employed. The spindles of the worms extend outside of the casings and are provided with pulleys 65 and 66 connected by a belt 67, power being communicated thereto in any desired manner. A casing 68 entirely or partially surrounds the conveyors and has abranch 69 opening into the conveyor casing 63 at or near the point 70 of entry of the coal. superheated steamat a relatively low pressure is conducted to the casing 68 by a pipe 71 controlled by a valve 72. The steam serves the purpose of preheating the coal in the conveyors and'finally is injected into the coal todisplace any air that is drawn in. It is to be noted that the ment of the coal itself.

into a blower 73 with the end of which com municates a pipe 74 controlled by a valve 7 5 through which is introduced superheated steam under a relatively high pressure to force the coal into the retort. This blower is in communication with. the retort 76and has its inner end located within the-retort and provided with a baffle 77 against which the coal is blown by the steam.

This blower may be inclined as desired in which case a less pressure will be necessary and larger pieces of coal can be used.

The showing in the drawings of the retort is somewhat diagrammatic, but it is usually formed in sections similar to those described in the other'form of apparatus. Certain of the sections have fins 78 on their interior 7 walls and underlying these fins are steam pipes 79. which pass through the walls of the retort and communicate with a main steam pipe 80. These pipes have upwardly directed perforations .so that the steam which is admitted under pressure is given an upward and inward direction as it issues from the pipes. Similar pipes may be passed through the middle of the retort so that steam will be admitted to a number of 4 points and directed against the coal at varying angles.

Also mounted within the retortare mechanical agitators 81 and withdrawal cylinders 82 which are operated from the outside by gearing designated generally as 83. A pipe 84 admits water to the lower part of the retort in which there is-reta-ined a water seal, and a worm or other conveyor 85 carries the coal out to a conveyor belt 86 or other desired means for removing the treated coal.

At the top of the retort is an outlet pipe 87 for the products of distillation and the superheated steam and this outlet pipe is provided with a steam with a valve 89 by whic a jet of superheated steam maybe supplied to the mixture at this point. A thermostat 90 is provided in the pipe 87 which controls the valve 89 and thereby the admission of steam so that the temperature may be maintained substantially uniform.

. The pipe 87 leads the vapors and steam into a cracking chamberlll where they impinge against a battle plate 92. A1rexit.

pipe 93 leads from the cracking chamber to a separator tank 94 and this pipe preferably enters at the side of the-chamber so that 'the *vapors are given a centrifugal motion which tends to precipitate the higher pitches and any solid particles that may have been carried over with the vapors. It also tends to separate the sulphur since ipe 88 provided the tank is maintained at a temperature at which the sulphur will be liquid.

In tl1is tank is placed a steam coil 95 connected to a pipe 96 by a branch pipe controlled by a valve 97. This valve is controlled by a thermostat 98 placed at the top of the vapor outlet column 99. If the type of material being treated requires it, the steam coil may be used for normal steam 'or even cold water, but this is unusual.

From the separator tank the vapors pass to a series of condenser chambers 100, 101, 102, and 103, the first three of which are substantially identical in construction.

- Each chamber is provided with a steam coil 104, 105, and 106 and the coils are connected to a steam pipe by short branches controlled b valves 107, 108 and 109 respectively. Thermostats 110, 111, and 112 control the valves 107, 108 and 109 respectively to keep the temperature in each chamber substantially at a given point. These thermostats are set as desired according to the particular fractions that it is desired to condense in each chamber. For example, if the thermostats 110, 111 and 112 are set at 518, 446, and 338 F. respectively, then the chambers 100, 101, 102 and 103, will condense the anthracene, creosote,

carbolio and benzene fractions respectively. These will be substantially pure in form and require little treatment before use.

. Each tank will be provided with appropriate means for drawing off the products condensed. If desired the thermostats ma be made double acting and may control: not only the valves for superheated steam, but also normal steam so that-the limits of temperature can be more accurately determined. Furthermore, a thermostat may be placed at the exit from the benzene eondenser and control the admission of water to a coil 113 in the chamber 103 and the Water column 114 above the chamber. This should be set just below the condensation point of benzene and will permit considerable free ammonia gas to pass off, which can becollected in any desired manner.

The gas will be conducted oft from the last condenser chamber through a pipe 115 and can receive any further treatment be; fore use that may seem necessary or desirable. Tt will be found suitable for many uses without any further purification.

It may be* found desirable in some cases to use some inert gas in the place'of steam,

but in the majority of cases, superheated ing chamber. produces the following imin the usual manner.

"vention. apparatus but it is obvious that the process retort by direct contact completely in the presence of such static electricity. This process therefore pro.- duces a more eflicient cracking than can be obtained by the same degree of heat applied It is to be noted that this process by a continuous operation produces gas, various products of distillation, and a valuable semicoke or synthetic anthracite. The semi-coke has substantially the fuel or heat producing .which comprises treating it in a closed revalue of the original coal, while the gas and other by-products are more valuable than the original coal itself.

Parts of the process may be used without others, and various changes may be made withoutdeparting from the spirit of my in- I have illustrated two forms of is independent of any .specific structure and may be carried out in widely varying structures. .I desire it to be understood that the invention is to be regarded as limited only by the scope of the appended claims.

'1 claim as my invention:

1. A process for the distillation of coal which consists solely in treating it in a closed with superheated steam under a pressure of not. less than five pounds. I

2. A process for the distillation of coal which consists solely in treating it in a closed retort by direct contact with superheated steam at about 1000 F. under a pressure of not less than five pounds.

3. A process for the distillation of coal which consists solely in bringing it into direct contact with superheated steam under pressure of not less than five pounds in the absence of air.

4. A process for the distillation of coal which comprisesplacing it in a retort, supplying superheated steam under a pressure of not less than five pounds thereto, leading off the steam and volatile products, and allowing the mixture to expand thereby reducing the pressure and temperature and condensing the desired fractions.

5. A process for the distillation of coal which comprises treating it in a, closed retort with superheated steam under a pressure of not less than five pounds, leading off the steam and volatile products, allowing the mixture to pass through successive expansion stages in each of which the pressure and temperatureis reduced and a particular fraction is condensed.

6. A process for the distillation of coal which comprises treating it in a closed retort with superheated steam under a pressure of not less than five pounds, leading ofi the steam and volatile products, allowing the.

mixture to pass through successive expansion stages in each ofwhich the pressure and temperature is reduced and a particular fraction condensed, and finally conducting off the remaining gaseous products for appropriate treatment and use.

7. A process for the distillation of coal which comprises treating it in a closed retort with superheated steam under a pressure of not less than five pounds, leading off the steam and volatile products, condensing desired fractions thereof separately, and collecting the remaining gas for use as desired.

8. A process for the distillation of coal densing chambers, regulating the temperature of certain chambers, and conducting off the remaining gaseous constituents for use.

10. A process for the distillation of coal 1 which comprises treating it in a closed retort with superheated steam, passing the mixture of steam and volatile productsthrough a series of condensing chambers, and automatically regulating" the temperature of these chambersto condense separate fractions of the distillate in substantially pure form.

11. A process for'thedistillation of coal which comprises treating it in a-closed retort with superheated steam passing the distillate into a cracking chamber, supplying additional superheated steam thereto in said chamber, and automatically condensing desired fractions thereof separately.

12. A pr0CeSs.f0r the distillation of coal which comprises treating it in a closed retort with superheated steam, passing the distillate into a cracking chamber with further addition of superheated'steam, leading the'mixture to a separator tank where heavy matters are removed by centrifugal force, and automatically condensing desired,

fractions separately.

13. A process for the distillation of coal which comprises preheating the coal, displacing the air indrawn therewith by an inert gas, feeding the coal into a retort, treating it therein With superheated steam under a pressure of not less than five pounds leading off the steam andproducts of distillation, and automatically separating the same into desired fractions.

14. A process for the distillation of coal which comprises preheating the coal with,

steam, displacing the indrawn air by steam, injecting the coal into a retort by the. aid of steam, and further treating the coal in the retort with superheated steam under pressure to distil off the desired constituents thereof.

15. A process for the distillation of coal which consists solely in treating it in a closed retort under a pressure of not less than five pounds with a highly heated inert gas which will not combine with the products of distillation, and continuing the treatment until a semi-coke is formed.

16. A process for the distillation of coal Which consists solely in treating it in a closed retort under a pressure of not less than five pounds with a highly heated inert gas until a semi-coke is formed, and leading off the products of distillation in suspension.

17. A process for the distillation of coal which comprises treating it in a closed retort with a highly: heated inert gas under a pressure of not less than five pounds, leading off the products of distillation in suspension, and automatically separating said products from said gas and into desired fractions.

18. A process for the distillation of coal which comprises treating it in a closed retort with superheated steam under a pres sure'of not less than five pounds, leading off the products of distillation in suspension, and automatically condensing the products in desired fractions. process for the distillation of coal 19. A which comprises treating it in a closed retort with superheated steam under a pressure of not less than five pounds, leading of the products of distillation in suspension, automatically condensing desired fractions of the mixture, and conducting the remaining gaseous elements for suitable treatment.

20. A process of making gas which comprises treating coal in a closed retort With superheated steam under pressure without any combustion of'thecoal, leading off the products of distillation in suspension in the steam, automatically of the distillate which become liquid at normal temperatures, and purifying the remaining gas as desired.

21. A process of making gas which comprises treating coal in a closed retort with superheated steam at about 1000 degrees F. without any combustion of the coal, leading off the products of distillation in suspension in the steam, separating the heavy particles and sulphur by centrifugal force, automatically separating the portions of the distillate which become liquid at normal temperatures, and treating the remaining gas as desired.

A process of manufacturing semicoke from coal which consists solely in subthe action of superheated steam in a closed retort under a pressure of not less than five pounds Without any combustion until all of the smoke forming constituents have been driven ofi.

23;A process of inanufacturing semicoke from coal which consists solely in subjecting it to the action of superheated steam in a closed retort in the absence of air and under a pressure of not less than five pounds until all of the smoke forming constituents have been driven off leaving only the higher pitch volatiles.

24. A process of manufacturing coke from coal which consists in subjecting it to the action of superheated steam at a temperature of about 1000 degrees F. 'in a closed retort under such pressure as to all smoke producing elements but retain elements that although volatile at a higher temperature are consumed in combustion.

In testimony whereof, I have hereunto subscribed my name.

. AME-s 'r. FENTON jecting the coal to separating the portions thereby remove

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