US1424749A - John henry west - Google Patents

Description

L'H. WEST AND A. JAQUES. METHOD AND APPARATUS FOR INCREASING THE.YIELD or HYDROGEN IN COAL GAS.

APPLICATION FILED MAY 13. 1922.

Patented Aug. 1, 1922.

Tfjl- UNITED STATES,

PATENT OFFICE.

JOHN HENRY WEST, OF BAYSWATER, AND ARTHUR JAQUES, OF WATERLOO, ENGLAND.

METHOD AND APPARATUS FOR INCREASING THE YIELD OF HYDROGEN IN COAL GAS.

Specification of Letters Patent.

Patented Aug. 1, 1922.

Application filed May 13, 1922. Serial No. 560,806.

To all whom it may concern:

Be it known'that we, JOHN HENRY Nnsr and ARTHUR JA UEs, both subjects of the King of Great Britain, and residing, respectively, t 33 Inverness Terrace, Bayswater, in the county of London, England, and 37 Sandringham Road, l/Vaterloo, in the county of Lancaster, England, have invented certain new and useful Improvements in or Relating to Methods and Apparatus for Increasing the Yield of Hydrogen in Coal Gas, of which the "following is a specification.

This invention relates to improved methods and apparatus for the production of hydrogen, its object being to increase the hydrogen content of gases evolved in the carbonization of coal.

In the processes for carbonizing coal generally employed a considerable proportion of the hydrogen present in the gases evolved is combined with carbon in the form of hydrocarbons, and such combined hydrogen thus reduces the amount of free hydrogen available. For the manufacture of gas for illuminating purposes there have been employed retorts constructed with both a horizontal and a vertical chamber in the former of which a fresh charge of coal was distilled for a suflicient length of time to drive off most of the volatile hydro-carbons therein which were subsequently converted into permanent inflammable gas by passing them through a more highly heated and partially carbonized mass of the same material contained in the vertical chamber. Otherarrangements of apparatus for a similar purpose have comprised two vertical retorts with a conduit connecting their bottom mouthpieces or a doubleretort with a centre partition having a passage therethrough so as to place in communication the two parts of the retort on each side of the partition; each retort or half of the double retort was charged alternately with the other so that the gas evolved from the fresh charge was caused to passthrough the partly spent charge at a higher temperature so that more.

of the tars etc, were decomposed andthe quality of the mixed gases maintained approximately constant. Further in the production from peat, lignite, or wood, of gas specially intended for illuminating, heating, and like purposes, it has been proposed to pass the gases produced by heating the afore mentioned substances in closed retorts, to-

gether with steam or hydro-carbon vapours,

obtained during the carbonization of coal than has hitherto been the case, this decomposition being carried to such an extent in accordance with our improved process that not only the tarry vapours and vapours of 'condensable hydro-carbons are decomposed but also a-high percentage of the so-called non-condensable gases such as ethylene and methane, whereby greatly increased yields of hydrogen are olotainedv According to the present invention the process for obtaining an increased proportion of tree hydrogen in the gases evolved during the carbonization of: coal, the said gases being intended for the production of hydrogen by extracting it therefrom, consists in passing the gases evolved during the initial stages of carbonization of the coal together with steam over partially carbonized coal or coke, the temperature of which latter has reached a value, for example 1000 C. to 1100 Q, relatively high compared with the temperatures obtaining during the initial stages of carbonization, and in effecting the carbonization at a rate sufliciently slow to allow of the decomposition of the greater proportion of all the hydrocarbon products, including the tarry vapours and even such gases as methane and ethylene, produced during the initial stages of the carbonization.

Inorder that the invention may be clearly understood and readily carried into eflect the same will now be described more fully with reference to the accompanying drawings which illustrate the application of the present process to a battery of coke ovens, and in which Figure 1 is a view of the apparatus in elevation, Figure 2 a transverse section work in pairs A B, C D, and E F and the individual ovens of each pair are placed 1n communication by means of the pipes G detachably secured to the doors K of the ovens, so that the gases from one oven can be passed through the other oven of the pair before passing into the common delivery conduit H. The pipes G are provided with steam pipes L for the purpose hereinafter referred to The operation of the apparatus is as follows :The carbonization is conducted ate slow rate, as will be hereinafter referred to, 1n order to permit of a maximum of decomposition of the hydro-carbons taking place. Considering the carbonization process to be in its initial stages in the ovens B, C, and E, and in a much later stage in the ovens A, D, and F, the gases rich in hydro-carbons evolved from the former set of ovens are led off through the pipes G where they become mixed witl steam introduced through the pipes L, and thereupon pass into the charge contained in the latter set of ovens in which the temperature is considerably higher than the temperature in the ovens B, C, and E. The hydro-carbons, such as methane, contained in the gases evolved from the ovens B, C, and E are decomposed during the passage of the gases through the ovens A, D and F, the decomposition being assisted by the steam which is also present and which combines with the carbon resulting from the splitting-up of the hydro-carbons and that present in the ovens A, D and F forming carbon-mon-oxide carbon-di-oxide, and hydrogen so that the gas entering the conduit G from the latter ovens contains higher proportion of hydrogen than would otherwise be the case. When the initial stages of carbonization have been completed in the ovens B, C, and E and the proportion of hydro-carbons in the gases evolved therefrom has become relatively small, by which time the carbonization of the charges in the ovens A, D, and F will have been completed, the coke is withdrawn from the latter ovens, the pipes G are reversed to the positions indicated in dotted lines in Figure 1, and the ovens B, C and E are then ready to be utilized for the decomposition of the hydro-carbons in the gases evolved from the fresh charges introduced. into the ovens A, D and F, which gases are passed together with steam into the ovens B, C, and E in which the charges are partially carbonized and now at a higher temperature than that of the ovens A, D, and F.

The presence of tle steam prevents the deposition of the considerable amounts of carbon produced by cracking of the tars hydrocarbon vapor: etc, which have given rise to considerab: uifliculties in processes heretoforecmhl. where steam has not been used.

The method of working described is applicable to coke ovens or horizontal or inclined gas retorts of the type which work intermittently, and of course it necessitates the ovens or retorts or groups of them commencing operation at different times. If, as in the case described the gases from the first ovens or retorts are passed together with steam directly into the second ovens or retorts, most of the tar in the gas will be decomposed and the hydrogen in it rendered available. If desired however the gases may first be passed throughsciaibbers and by-product plant in the usual way and only the stripped gas issuing therefrom be passed together with steam into the second oven or retort.

In the case of vertical gas retorts of the type which work continuously, the gas evolved in carbonization instead of being led out at the top of the retort as is the usual practice, is drawn off at the lower part, at or below the zone of maximum temperature, where the carbonization process is completed and where the decomposition of the hydrocarbons with the aid of' steam is effected.

The present invention is also applicable to the type of horizontal or inclined retort in which one end of the retort is maintained at a high temperature relatively to the other parts of the retort and particularly to retorts of the type in which there are arrangements for continually feeding the coal or coke forward.

In carrying out the present process, the carbonization is carried out at a comparatively slow rate and the duration of the initial stage of carbonisation of the fuel, during which the greater part of the hydrocarbons are driven off and are conducted togeth er with steam through a succeeding oven or retort, is equal to about one-half-say for example fifteen hoursof the total coking period, and during this period the tempera ture gradually rises to about 9000 C.

The hydrogen is separated from the mixture of gases in any suitable way, for example by processes such as described in the specifications of British Patents Nos. 130092, 130358 and 131,091 and the invention is ob viously particularly applicable for the production of hydrogen for the synthetic manufacture of ammonia.

hat we claim and desire to secure by Letters Patent of the United States is:

1. A process for obtaining an increased proportion of free hydrogen in the gases evolved in the carb'onization of coal, the said gases being intended for the production of hydrogen byv extracting it therefrom, which process consists in stripping the gases evolved during the initial stages of the carbonization of the coal by subjecting them to a purifying treatment for removal therefrom of the tarry vapours, adding steam to the stripped gases, passing the mixture of stripped gases and steam so obtained over the partially carbonized coal or coke, the

temperatures of which latter has reached a value relatively high compared with the temperatures obtaining during the aforesaid initial stages of carbonization, and in effecting the carbonization at rate suiiiciently slow to allow the greater proportion of all the hydrocarbon products including the tarry vapours and even such gases as methane and ethylene, produced during the initial stages of the carbonization, to be decomposed during their passage over the aforesaid partially carbonized coal or coke.

'2. ii process for obtaining an increased proportion of free hydrogen in the gases evolved. in the carbonization of coal, the said gases being intended for the production of hydrogen by extracting it therefrom, which process consists in adding steam to the gases evolved during the initial stages of the carbonization of the coal, the said initial stages of carbonization of the coal occupying a period of time equal to about onehalf of the total coking period, passing the mixture of gases and steam so obtained over partially carbonized coal or coke, the temperature of which latter has reached a value relatively high compared with the,

temperatures obtaining during the aforesaid initial stages of carbonization, and in effecting the carbonization at a rate suiiiciently slow to allow the greater proportion of all the hydrocarbon products including the tarry vapours and even such gases as methane and ethylene, produced during the initial stages of the carbonization, to be decomposed during their passage over the aforesaid partially carbonized coal or coke.

3. A process for obtaining an increased proportion of free hydrogen in the gases evolved in the carbonization of coal, the said gases being intended for the production of hydrogen by extracting it therefrom, which process consists in adding steam to the gases evolved during the initial stages of the carbonization of the coal, the said initial stages of carbonization of the coal occupying a period of time equal to about one-half of the total coking period, passing the mixture of gases and steam so obtained over partially carbonized coal or coke, the temperature of which latter has reached a value of 1000 C. to 1100 C., and in effecting the carbonization at a rate sufficiently slow to allow the greater proportion of all the hydrocarbon products including the tarry vapours anl ven such gases methane and ethylene, produced during the initial stages of the carbonization, to be decom posed during their passage over the aforesaid partially carbonized coal or coke.

at. A process for obtaining an increased proportion of free hydrogen in the gases evolved in the carbonization of coal, the said gases being intended for the production of hydrogen by extracting it therefrom, which process consists in stripping the gases evolved during the initial stages of the carbonization of the coal by subjecting them to a purifying treatment for removal therefrom of the tarry vapours, the said initial stages of carbonization of the coal occupying a period of time equal to about one-half of the total coking period, adding steam to the stripped gases, passing the mixture of stripped. gases and steam so obtained over partially carbonized coal or coke, the temperature of which latter has reached a value relatively high compared with the temperatures obtaining during the aforesaid initial stages of carbonization, and in effecting the carbonization ata rate sufficiently slow to allow the greater proportion of all the hy drocarbon products including the tarry vapours and even such gases as methane and ethylene, produced during the initial stages of the carbonization, to be decomposed during their passage over the aforesaid partially carbonized coal or coke.

process for obtaining an increased proportion of free hydrogen in the gases evolved by the carbonization of coal in coke ovens, the said gases being intended for the production of hydrogen by extracting it therefrom,which process consists in leading off the gases rich in hydrocarbons evolved from the oven or ovens in which the car bonization'process is in its initial stages, adding steam to the said gases rich in 'hydrocarbons, passing the mixture of gases and steam so obtained into a second oven or ovens in which the carbonization process is at a much later stage and where the temperature is cons'iderabley higher than in the first mentioned oven or ovens, and in effecting the carbonization at a rate sufliciently slow to allow the greater proportion of all the hydrocarbon products including the tarry vapours and even such gases as methane and ethylene, evolved from the oven or ovens in which the carbonization process is in its initial stages, to be decomposed during their passage through the second over on ovens in which the carbonization process is at a much later stage.

6. A process for obtaining an increased proportion of free hydrogen in the gases evolved by the carbonization of coal in coke ovens, the said gases being intended for the production of hydrogen by extracting it therefrom, which process consists in lead ing off the gases rich in hydrocarbons evolved from the oven or ovens in which the carbonization process is in its initial stages, stripping the said gases by subjecting them to a purifying treatment for removal therefrom of the tarry vapours, adding steam to the stripped gases, passing the mixture of stripped gases and steam so obtained into a Second oven or ovens in which the carbonization process is at a much later stage, and where the temperature is considerably higher than in the first mentioned oven or ovens, and in ellecting the carbonization at a rate sutliciently slow to allow the greater proportion of all the hydrocarbon products including the tarry vapours and even such gases as methane and ethylene, evolved from the oven or ovens in which the carbonization process is in its initial stages, to be decomposed during their passage through the secon d oven or ovens in which the carbonization process is at a much later stage.

7. A process for obtaining an increased proportion of free hydrogen in the gases evolved by the carbonization of coal in coke ovens, the said gases being intended for the production of hydrogen by extracting it herefrom, which process consists in leading off the gases rich in hydrocarbons evolved from the oven or ovens in which the carbonization process is in its initial stages, stripping the said gases by subjecting them to a purifying treatment for removal therefrom or the tarry vapours, adding steam to the stripped gases, passing the mixture oi stripped gases and steam so obtained into a second oven or ovens in which the carbonization process is at a much later stage, and where the temperature has reached a value of 1000 C. to 1100 (3., and in effecting the carbonization at a rate suiiiciently slow to allow the greater proportion of all the hydrocarbon products including the tarry vapours and even such gases as methane and ethylene, evolved from the oven or ovens in which the carbonization process is in its initial stages, to be decomposed during their passage through the second oven or ovens in which the carbonization process is at a much later stage.

8. A process for obtaining an increased proportion of free hydrogen in the gases evolved in the carbonization of coal in coke ovens, the said gases being intended for the production of hydrogen by extracting it therefrom, which process consists in leading oil the gases rich in hydrocarbons evolved from the oven or ovens in which the carbonization process is in its initial stages, the said initial stages of carbonization of the coal occupying a period of time equal to about one-halt oi the total coking period, adding steam to the said gases rich in hydrocarbons, passing the mixture oi gases and steam so obtained into a second oven or ovens in which the carbonization process is at a much later stage and where the temperature is considerably higher than in the first mentioned oven or ovens, and in effecting the carbonization at a rate suiiiciently slow to allow the greater proportion of all the hydrocarbon products including the tarry vapours and even such; gases as methane and ethylene, evolved from the oven or ovens in which the carbonization process is in its initial stages, to be decomposed during their passage through the second oven or ovens in which the carbonization process is at a much later stage.

9. Apparatus for carrying out the carbonization of coal so as to obtain an increased proportion of free hydrogen in the gases evolved by the said carbonization, comprising a series of coke ovens arranged to work in pairs, a common delivery conduit for the gases evolved from the said series of ovens, pipes detachably secured to the doors of the ovens of: each pair, whereby the gases from one oven can be passed through the other oven of the pair before passing into the common delivery conduit, and steam pipes connected to the aforesaid detachably secured pipes for the admixture of steam with the gases passing from one oven of a pair into the other ovenof the pair.

JOHN HENRY WEST. ARTHUR JAQUES.

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