US2177226A - Method of making coke - Google Patents

Description

Patented Oct. 24, 1939 UNITED STATES mmrop or MAKING cons Earl W. Rice and Walter J. Buchele, St. Paul, Minm, assignors oi sixty-six and two-thirds per REESSUEQ cent to Courtney W. Kimier, 8n, and Harry Hall, Ames, Iowa No Drawing. Application May 23, 1938,

I Serial No. 209,529

4 Claims.

The object 01 our invention is to afford a method of making coke which consists broadly in adding to petroleum carbon coke fines or breeze a proper amount of pitch derived from 5 the bi-products coke industry, having the characteristics hereinafter mentioned and charging the mixture into a vertical bi-product coke oven and subjecting same to coking temperature until practically all volatile gases have been is driven off and coking action is completed.

Our invention consists in the selection and.

mixing of the ingredients and treatment of the mixture as hereinafter more fully set forth.

Petroleum coke is a product of the oil distillation or cracking process as now practiced in the petroleum industry. A great percentage of petroleum coke is produced or recovered in the fine state or in what is called breeze form. These fines are difficult to market in their present state. They are smoky, greasy and dirty to handle. The fines are produced by the method of extraction from the stills; where chains, balls and other means are used to break up the accumulation of coke in the stills, as fast as posg sible to save time in clearing the stills and to make them quickly ready for the next run. What is wanted is gasoline, not coke. It readily resolves itself down to the point that the petroleum coke is a necessary evil of the oil cracking process and must be removed as quickly as possible regardless of the state or form of the resultant product. There is available a great quantity of this coke breeze for which there is no market.

The pitch used is a resultant of coal tar and hl-product coking processes, and is used in a refined state. The melting point of the pitch must be such that the mixture will not efiervesce excessively and foam out the vents of the coke oven and thus clog up the vents when charged into ovens carrying a coking temperature.

The temperature at which the pitch will eiiervesce will vary. In that we mean a pitchof lower melting temperature can be' used if the ovens are kept at 1800" F., than if oven temperature of 2200" is used. Lower melting point pitch can be used in a 14" oven and oven temperature of 1800; than would be necessary to use in a. is" oven with 2200 temperature. This means that a 5 wide variation in melting range of pitch can be used and one must use the pitch best, adapted when charged into cokingoven at coking temperature or during the coking process.

A great many unsuccessful attempts have been made to utilize petroleum coke breeze and form it into hard solid pieces of a size adapted to metallurgical and domestic use. In fact we were discouraged by many coke producers who stated that they had spent hundreds of thousand of dollars trying to do what we claimed we could do.

At the plant where our tests were run; the

. results of which appear later, we had to guarantee them against damage to ovens. Then they were so pessimistic and suspicious of our process, and our inability to push the finished product from the ovens that we had to start with charge of our materials and charge of. bi- .product materials. Finally weused then of our materials and less bi-product in proportion, then a full charge of our material, and amperage on pusher was not raised.

We use a mixture of from to 95% petroleum coke breeze to form 59% to 5% pitch m a fine state thoroughly mixed, and charge same into a vertical lei-product coke oven and seal same against admission of air which is ordinary coking practice; subject the charge to a coking temperature until coking action is completed. Then vents are opened and charge pushed into the quenching car where it is quenched, which is also ordinary coking practice.

In our test a core pitch with a melting point of 284 F. was used. Core pitch can be secured with a melting range between 270 and 315 F. But any pitch that will not efiervesce excessively and clog the oven can he used.

It a coke having some volatile gases is desired, the coking action can be stopped and cl i arge pushed out before all gases are distilled If a hard, dense metallurgical coke is desired, the action can be carried to completion and practically all volatile gases eliminated with a result approximately as follows: 99.19% fixed 0.;

iii

tit

.37% ash; 44% volatile (and .65% sulphur).

The length of coking time depends on oven temperature, width of even, capacity of oven, etc.

In-our tests a temperature 01' between 1700 and 1854 F. was used in a 1'7" oven on a coking time oi approximately 32 hours, with excellent results.

If the oven is narrowed this coking time can be reduced, and if temperature is raised, the coking time will be reduced. If both the temperature is raised and the oven narrowed the coking time can be materially decreased until it a 'is possible to secure a coking cycle of between 4 and 8 hours.

We use a vertical bi-product coke oven because in the horizontal type oven a thin layer is heated from below, and a great amount of sponge coke is formed on the exposed surface which results in a greater percentage of finesin the final product. With a vertical bi-product coke oven the dust loss or fines are practically negligible.

Our process is a practical process and pro-- duces a high grade, hard coke, of good size and especially adapted to high grade metallurgical us It can also be used domestically as our tests have proven.

This product is a high grade metallurgical coke, high in fixed carbon, low in volatile and ash,

I uable in the steel and metallurgical industry.

By this method we have taken two low priced, nearly waste products and produced a. finished coke having a commercial value of about twice that of its ingredients with a -loss of about 13%. Never heretofore has a high grade metallurgical coke been produced by merely putting together petroleum coke and pitch only and subjecting them to, a coking temperature in a vertical biproduct coke oven for the proper time.

This may be because it is known that with ordinary pitches, boiling or effervescing would set up so 'quickly as to make such a method practically impossible and unworkable. Among other things the gummy mass would not push through the ovens.

For the purpose of further illustration, the following table sets forth the results of a number of experimental runs which were made in accordance with the present invention. These experimental runs were made with core pitch (M. P. 284 F.).

physical characteristics. Samples taken from one representative batch of this new synthetic fuel showed the following analysis:

TABLE No. 2

Volatile Fixed Materials charged H mat-m carbon Asl1 Sulphur Granular petroleum carbon 7.60 7.37 92.31 .32 .84 51. 58 48. 23 l9 47 Mir 1 15. 11 84. 58 31 .70 Resultant coke 44 99. 19 37 65 TABLE No. 3 Tumbler test Charged Total in drum Percent 011 2 screen Percent on 1% screen Through drum. Percent on 1' screen... Perccnt on M" scrccn Percent through )6 screen Dust loss Monomer.

95: 3??? MWOOOGKIMQ The standard A. S. T. M. formulas based on standard red brick for calculating the strength, hardness and brittleness gives the following results on this sample:

v 100 Brittleness=(100-A)-F=31.1

Apparent gravity=1.14 True gravity (GS-mesh screen)=l.85 'The chemical analyses of the product of other the present invention have been subjected to laboratory tests for chemical composition and TABLE No. 1 runs was as follows: 1

Length reaction Pitch r Approx. aver. Amount ,OOOI oven temp. Percent Oven No. of charge of carbon (optical yield Character of product Pymmeter) Hrs. Min.-

Pounds Pounds F. 5,000 400 1810 87.8 32 24 Excellent.

2% a la a .2 24I900 500 1100 88:7 33 20 Excellent. 24,100 500 1144 89.1 as 34 Do. 20,400 500 1100 88.6 a2 24 Do.- 26,880 500 1854 83.3 32 as p0.

It should be noted that the present invention TABLI No. 5 may be practiced utilizing temperatures ranging from 1600 to 3000 F. and the reaction may be I volatile Fixed carried out for a period of time ranging from 4 Sample matter carbon Sulphur to 40 hours. The variation in temperature and reaction time depends upon the size of the reg 3% 1% tort used,'the quantity of material and similar 96:37 discretionary factors. 9118 1- 1 Samples of the coke made in accordance with present invention makes possible the production It will be seen from the above data that the coal.

of a new solid fuel, unlike any existing fuels. This present fuel is hard, clean to handle, has

not less than 97% of fixed carbon, has less than TABLI: No. 6

Absolute structural strength Cube size Ultimate strength Test No.

Height Dimensions ar Total gang?" Inches 4 S1,. in. Pound: L81 X 1.67 3. 03 3, 340 1,102 .975 x 1.265 1. 23 1,82) 1,480 L48 x 1.56 2. 3i 2, 210 957 2.15 X 1.49 3. 2 3,190 997 1.50 X L64 2. 40 2.790 1,134

Average... 1.134

These ultimate strength values are'quite comparable to the ultimate strength values desired for high grade metallurgical fuels made from It has never been possible to manufacture a coke from these materials that carries the necessary sizing and has this structural strengthvalue. In fact a fuel produced in accordance with the present invention has a structural strength which is more than, double the structural strength of any previously prepared' fuel of this general character.

This application is a continuation-in-part of applicants application Serial No. 132,594, filed March 24, 1937.

It is to be understood that, although some particular compositions embodying the present invention and methods of. producing the same and also some of the arts in which the present invention may be utilized have been set forth and discussed above, nevertheless the present invention is not limited to the exact ingredients or proportions or to the precise methods or those arts mentioned, the scope of said invention being commensurate with the following claims.

We claim:

-1. A method of producing a metallurgical coke from-petroleum coke consisting of the mixing of petroleum coke breeze or fines, with pitch derived from the bi-product coke or coal tar industry, in the proportion of from 50% to 95% by [weight of petroleum coke breeze or fines and 50% to by weight of pitch in fine state and charging same into a vertical bi-product coke oven and subjecting to a coking temperature until coklng action is completed, producing a metallurgical coke having approximately the following analysis: 99.19% F; C.; .37% ash, .44% volatile and .65% sulphur; I

2. A method of producing a metallurgical .coke from petroleum coke consisting of the mixing of petroleum coke breeze or fines with "core pitch in the proportion of 50% to 95% petroleum coke breeze or fines with from 50% to 5% "core pitch in fine state, charging same into a vertical biproduct coke oven and subjecting same to a cokring temperature until coking action is completed, producing a metallurgical coke having approxi- 'mately the following analysis: 99.19% F. C.;

37% ash, .44% volatile and .65% sulphur.

.3. A method of producing a metallurgical coke from petroleum coke consisting of mixing of petroleum coke breeze or fines with pitch derived from the distillation of coal tars and having a melting point such that it will not eflervesce excessively and clog the oven vents, in the proportion of 50% to 95% petroleum coke breeze or fines with from 50% to 5% of said pitch ina fine state, charging said mixture intoa vertical biproduct coke oven and subjecting same to a coking temperature until coking action is completed, producing a metallurgical coke having approximately the following analysis: 99.19% F. 0.; 37% ash, .44% volatile and .65% sulphur.

4. A method of producing a metallurgical coke from petroleum coke consisting of the mixing of petroleum coke breeze or fines, with pitch derived from the bi-product coke or coal tar industry, in the proportion of "from 50% to 95% by weight of petroleum coke breeze or fines and 50% to 5% by weight of pitch in fine stateand charging same into a bi-product coke oven and subjecting to a coking temperature until coking action is completed, producing a metallurgical coke having approximately the following analysis: 99.19%

g F. C.; .37 ash, .44% volatile and .65% sulphur;

EARL W. RICE. WALTER J BUCHELE.