USRE12971E - Heinrich koppers - Google Patents

Description

H. KOPPERS;

PROCESS OF OBTAINING AMMONIA AND TAR,

APPLICATION FILED OCT. 14,1909.

Reissued June 8, 1909.

flz'iheu xek, a. Z amp/Mm UNITED OFFICE.

' HEINRICH KOPPERS, or EssEN-oN-THs-RUnri', GERMANY rnocnss' OF OBTAINING AMMONIA AND TAR.

Specification of Reissued Letters Patent. Reissued June 8, 1909.

Original No. 32,976, dated August 13, 1907, Serial No. 288,488. Application iorreissue filed October 14, 1908.

Serial No.

separating the by-products from gases of dr 7 distillation or gasification of fuel, by whic process the tar and ammonia are obtained in a more simple, pure and economicalmanner than heretofore. By my invention the s'; pa-

ration'of each product takes place at the tern perature best adapted therefor, while the separation of the tar is effertedbefore the ammonia is obtained.

In the accompanying drawing: Figure 1 is a sectional elevation of a plant for carrying my invention into effect, and Fig, 2 a plan of the saturating vessel and adjoining parts,

An oven, such as stroke oven, gas retort or other gas producer, is connected'by tube 1,

with the head 2 of a heat exchanger 3, said head communicating with the base 5 by .a cluster of ipes 4. A tube 6, controlled by valves 6, eads from exchanger 3, to a pair of parallel coolers.7, the temperature of which may be lowered in known manner by water or other cooling liquid supplied by a pl e27; From the top of coolers 7, a ipe 8, w iich is controlled by valves 8*, lea s to a suitable tar separator 9 which is, by pipe 10, connected to a filter 11. This filtercomrises a vertical cylinder with a number of inner concentric perforated annular walls 12 that form compartments for the reception of the filtering material.- The latter is com' posed'of layers of coke or similar matter, which gradually increases in finenessfrom the exterior toward the interior of the filter. The tar and water here separated descend to the bottom of the filter, from whence the may be withdrawn through a pipe 28 which i also takes up the condensate formed in heat exchanger 3, and'coolers 7 and 24, herein A pipe 13 leads from the filter back to that chamber of exchanger 3, which is traversed by pipes 4 between head 2 and base 5. From the top of this chamber a pi 14 leads to a saturation vessel 15 with -w ich it communicates through an annular finel .pertured channel 17 arranged near the ottom of vessel 15. This vessel, which is preferabl closed, has a lead lining and is partly fille with dilute acid. Pipe28 cornmunicates through brahch 28" with a tar separator 31 which is, in turn, through pipe 28 connected to a distillation ap aratus 32. I

The latter communicates througi pipe 28 with pipe 14, and consequently with vessel 15. cavity 16 in the bottom of vessel 15 separated in the form of fine crystals. An 1n ector or' similar device29 raises the salty serves for the reception of the salt which is recipitates from vessel 15 into a trough 18,

rom which they enter a centrifugal drier 19. The li uid in trough 18' passes through tube 26-bac into saturation vessel 15. Any tar that collects at the bottom of said vessel may be removed by a suitable ladle which ma be introduced into the vessel through an 0 eni-ng 30. The acid necessary for replenis ing the bath may, if desired, also be introduced through this opening. From the cover of vessel 15 a tube 20 leads to'a gas suction device 21 which, by pipe 23, is connected to a cooler 24 provided with a gas exit pipe 25. 'The operation is as follows: The raw gas from the oven passes through pipe 1, into ex-v changer 3, where it flows through pipe-cluster 4, in which it is cooled by the cold gas flowing from tube 13 around said cluster. A further intensive cooling of the gas to any point desired is next effected in coolers 7, by a suitable cooling medium. 'lhereduction of temperature should be such that the subsequent separation of the tar will take place under the most favorable conditions. This separation is effected in known manner within the tar separator 9 and the tar filter 11, in which, owing to the treatment described, the

--tar is obtained almost in full quantity and in a pure state.

As the tar does not come into contact with the acid, it is acid free and not decomposed. The gases leaving tar filter 11 will, owin to their low temperature, carry but a smal percentage of water. As these gases are conveyed by pipe 13 to exchanger 3, where they surround the pipe cluster 4',

. which is charged with the hot gases, they will become re-heated to a temperature Which may be raised to a suitable degree. This ,temperature is in each case so selected as to be most favorable for the direct production of ammonium sulfate. As the gases-now contain relatively less water than can be carried at this temperature, the vapor suspended in the mixture is superheated, so that its temperature may be considerably lowered before a condensation of water will take place and that vaporization may also take place tained bulk of the tar.

even in the saturation vessel to which the gas is conducted throu h ipe 14. IVessel 15 is filled with a bath 0 su furic acid, or an acidsalt solution. This bath has a concentration always-at an'appropriate tern erature for the of about 30-33 Baum, an is maintained urpose of preventing any condensation. he necessary degree of concentration is maintained by adding sulfuric acid as required.

As the gas assing into the bath through the perforate( ring 17 is superheated and thus possesses the faculty of taking up water, a vaporization of the water produced in the acid bath can take place. While the gas passes through the bath, it gives'up its am' monia to the free acid and then flows from vessel 15 through tube 20 into the gas suction device 21 thatforces it into cooler 24, where any water contained in the gas is condensed.

In order thatany organic substances which have not been separated in the tar separator 9 and filter 11, will not be attacked in the acid bath, a weak acid bath, with as constant a strength as possible, is used. The constancy of the latter is maintained by continu- 'ous'ly adding" fresh acid and removingthe salt. If, in this manner, the quantity of the added acid corresponds exactly to the quantity of acid which combines with the ammonia to form the salt, the desired constancy of the acidity is obtained. As this bath can only acquire a certain degree of concentration, it will not attack the tar, and especially not the readily boiling components thereof.

The rest of the organic components will therefore pass unchanged through the bath,

to be finally separated together with the water and to be added to the previously ob- Any thickened tar that may reach the saturation bath, may be removed therefrom by any suitable mechanicalappliance, such as a ump.

The gas leaving the. co 'e oven, gas retort.

or other gas producer, contains the ammonia a part of whlch is combined with acid. This part of the ammonia is separated before the dew point of" t passage through the saturation vessel, in the form of a weak saline solution, together with the tar and water and may be treated in any suitable manner.

If the process is to becarried out that p r ac tically the entire quantity of water contained in-the raw gas is to be finally precipitated in cooler 24, where it appears as pure water, the operation is as follows:

During the -cooling of the gases, care is taken that the minimum temperature reached corres onds, substantially, to' the he gases. The dew point of retort gas is about 72 centigrade, andfthat of coke oven gas is about 85 centigrade, at

resulting liquor to thesaturation bath.

a barometer stand of .760 millimeters. This difference arises from-the higher percentage of water in the coke oven gas, as coking coal,

owing to the washing process, generally contains a greater percentage of' water than gas coal. The tar will thus be condensed in the form of a mist floating in the gas and is obtained in this condition in the tar separator. If the gases are now superheated, as before, and conducted through. the acid bath, they will carry their full charge of water, or at least the greater part thereof, through the entire operation, so that the water is condensed mainly in the -terminal cooler 24, in the form of pure water. possesses, however, a certa n element of uncertainty, as it is difficult to retain a fixed temperature, and furthermore, as the. temperature required in the saturation vessel must be higher than that most favorable for the interaction between the ammonia and the acid,

I claim:

This operation 1. 'Process'of obtaining ammonia and tar from the gases 'of'the dry distillation or gasification of fuels, which consists in coolingsaid gases so as to condense tar and water,

passing the gases through.a tar separator,

withdrawing the tar, superheating the gases freed from tar, and conducting said gases to an acid saturation bath.

2. Pro( ess of obtaining ammonia and tar from the gases of the dry distillation or gasification of fuels, which consists in cooling said gases so as to condense tar and water, passing the gases. through a tar separator, withdrawing the tar, superheating the gases freed from tar, conducting said gases ,to an acid saturation bath which is maintained at a uniform concentration by means of a constant supply of acid and a constant withdrawalof the deposited salt, conducting the withdrawn salt to a drier, and returning the 3. Process of obtaining ammonia and tar from the gases of the dry distillation or gasi .fication'of fuels, which consists in cooling said'gases to approximately the dew point of water saturation, so as to condense the tar in the form of a mist floating in the gases, passing the gases through a tar separator, Withdrawing the tar, super-heating the gases freed from tar, conducting said gases to an acid saturation bath which is maintained at a uniform concentration by means of a constant supply of acid'and a constant withdrawal of the deposited salt, conducting the withdrawn salt to a drier, and returning the resulting liquor tothe saturation bath.

Witnesses:

. LOUIS WILPUTTE, FRANK V BRIESEN.

' HEINRICH KoPPERsH

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