US2325916A - Manufacture of liquid hydrocarbons from gaseous and solid carbonaceous materials - Google Patents

Description

Aug. 3, 1943. c, 1 ocoN ET AL MANUFAGTURE oF LIQUID HYDRocARBoNs FROM GAsEoUs AND soLID cARBoNAcEoUs MATERIALS Filed April 24, 1939 Y' Genval/snow Gases 2,325,916 AsEoUs 2 Sheets-Sheet 2 Qms GEA* .m MW

ID HYDROCARBONS FROM G ARBONACEOUS MATERIALS c. L ocON Erm.

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Filed April 24, 1939 AND SOLID C MANUFACTUHE 0F L Aug. 3, 1943.

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Patented Aug. 1943 MANUFACTURE F LIQUID HYDEOCABBNS FROM GASEOUS AND SOLID CARBONA.- CEOUS MATERIALS Cecilio L. Ocon and Ernest A. Ocon, Yonkers,

N. Y.; said Cecilio L. Ocon assigner to Ernest A. Ocon Application April 24, 1939. serial No. 269,666

(ci. 19e-56) v4 Claims.

-This invention relates to the art of converting gaseous hydrocarbons into high anti-knock motor fuels, and more particularly to a process in which highly heated gaseous hydrocarbons assist in a destructive distillation of solid pyrobituminous material with mutual benefit to the reaction of the gaseous hydrocarbons and to the treatment of the solid material.

It has already been proposed to destructively distill raw coal in the presence of petroleum oils undergoing destructive distillation at ordinary cracking temperatures, but such processes have not been adopted commercially on account of their vlow yields of motor fuels or other valuable the solid fuel is past its plasticizing or fusion stage. Following this preheating, the solid fuel in a dry state is contacted with reactive gaseous hydrocarbons at a suillciently high temperature to promote decomposition of the solid fuel into gaseous hydrocarbons and solid carbonized residues; simultaneously, gaseous hydrocarbons introduced for heating the solid fuel are inducedy to undergo polymerizing reactions. Resulting carbonized solid residues may then be treated to completely gasify their remaining non-volatile carbonaceous components under conditions which leave a highly adsorbent ash of inorganic substances, suitable for use in catalytically splitproducts, when the products are evaluated in ting higher boiling hydrocarbon vapors into gasocomparison with the cost of handling the coal line hydrocarbons. In this manner the process and the difliculties of recovering the desired low is capable of producing a wide range of volatile boiling distillates from the tarry mixtures formed. products without waste of heat or materials.

Some of the main objects of this invention are: For a better understanding of the invention to increase production of high anti-knock liquid 20 the following illustrative example is given, other fuels from pyrobituminous solids, e. g. coals, submodifications being within the purview of this jected to vdestructive distillation in a practical and invention. economical manner; and to effectively utilize py-l A bed of dry coal, for example, is subjected to a robitumens undergoing carbonization, their prodbatch treatment by first treating the coal to a ucts, and addition agents to promote polymerizapredetermined high temperature with a hot blast tion of gaseous hydrocarbons with reduced 'tar 'of relatively inert gases, such as flue gases or air formation. blow combustion products, which may contain a It is within the contemplation of this nvenl small amount of free oxygen or air. Coal partion to effect a complete liquefaction and gasil-I ticles of the bed are sumciently large so as not to cation-of carbonaceous material in coal, thus exbe swept away by the blast of gases, but small tending the Autility of the process further to proenough for rapid heat conduction, when they are duction of Water gas and an inorganic residue able to passa 4 mesh screen. This preheating suitable for use in catalytically cracking higher period is restricted so that the coal is brought boiling hydrocarbon vapors to gasoline hydrocarrapidly to a temperature above 800 F., before it bons. begins to undergo substantial destructive distil- A major advantage obtained by proper control lation, in orderto avoid the formation of tarry and combination of the various reactions accordliquids, which are produced more readily when Ying to the present invention is obtained in the the coal tends to fuse into a'plastic mass. This increased yield of more valuable products with plasticizing of the coal occursprincipally when economy of heat energy input, handling of ma- 40 ,the coal is heated in the range of 600 to 800 F., terals, and exhaustive use of materials treated. but it can be overcome by supplying the blast of Other objects and advantages will become apheating gases at an adequate rate of flow and a parent from the following description. high temperature. The heating gasesare suplTo obtain the desired results, whether in a plied preferably at a rate above 10 cu. ft. per secbatch or continuous treatment, the coal or s olid ond per pound of coal and at a temperature above pyrobituminous material is transformed in stages. 850 F., these conditions varying in accordance The batch procedure is cyclically carried out in with the amount of preheat retained by the coal apparatus similar to gas generators in design. from a drying treatment, quality and size of coal, For conducting an efficient continuous treatment and other governing factors. With the temperthe solid material is preferably used in a finely ature of the coal brought toabout 800 F., highly divided form. heated gaseous hydrocarbons from a highl heat The main process steps comprise a rapid preresistant alloy heating coil are led into the hot liminary heating of the solid fuel with limited coal at a coil outlet temperature of about 1000 vaporization of volatile constituents to bring the F., to about 1300 F., in place of the blast of presolid fuel to a temperature above 800 F., so that 55 heating gas. Thus begins the period of coal decomposition and carbonization to form coke. While supplying heat for the carbonization, the highly heated reactive hydrocarbon gasesl largely composed of olefins and free hydrocarbon radicals, are given opportunity to polymerize and react with gaseous products from the coal in the presence of the coke thus being produced. The vaporous products withdrawn from the reaction zone vcomprise valuable high anti-knock motor fuel hydrocarbons including aromatics, alkylated aromatics, naphthenes, alkylated naphthenes and other complex organic motor fuel compounds substantially free from tarry bodies.

After termination of coal carbonization, as indicated by substantial decrease in distillate yield, the resulting coke bed is ready for an air blowing to heat lower layers of the coke bed to incandescence, generally with a short preceding purge by superheated steam. To avoid clinkering of ash residue the temperature of the coke bed is maintained below maximum temperatures of about l800 F. to 2500 F.; this can be partly regulated by injecting steam with the air into the coke bed.

Hot products from the air blowing step contain predominately carbon dioxide, nitrogen, and steam, a. small amount of carbon monoxide and excess oxygen. With high exit temperatures, these products are very useful for initiating distillation of a new coal bed through rapid preheating past the plasticizing stage of the coal, although heat recovery may be made from them in some other manner.

After the temperature of the coke bed has been brought to a high degree favorable for carbon monoxide formation, i. e., about 1500 to 2000 F., superheated steam is passed therein to produce water gas, until the carbon monoxide and hydrogen yield drops and a substantial portion of the coke bed has been gasifled, leaving an ash residue. Carbon dioxide may be injected with the superheated steam to produce water gas. A

The remaining ash and any residual coke may then be used while in heated condition to' serve as a contact mass for dry hydrocarbon vapors led in from a cracking coil at a coil outlet ltemperature in the range of about 800 to 950 F. In the -form obtained, this contact mass functions to eliminate undesirable entrained tarry bodies and other impurities. also to favor increased yields of purified distillates by furthering the splitting reaction of higher hydrocarbons and promoting polymerization of normally gaseous hydrocarbons formed by the splitting reaction.

A number of the steps may be carried out eiliciently with a continuous procedure ,to be more fully described in commotion withxthe drawings. In the continuous procedure the coal or solid fuel is more advantageously first reduced to a pulverized condition by grinding until it is -able to pass a screen of about to 40 mesh, or nner.

It is also advantageous to agglomerate a powdered fuel with an adhesive material which upon being dried acts as an adsorbent and catalyst. Examples of substances useful in this capacity are silica gel, alumina gel, bentonite gel and similar inorganic substances which upon drying form refractory porous masses of large surface area. By heating and agitating these substances with the powdered fuel, agglomerated pellets are formed. These pellets are preferably reduced in size by a further grinding to particles fine enough -to pass at least a 20 mesh screen, and these particles may be given an activation treatment by contact with inorganic acidic gases, such as oxides of phosphorus, oxides of sulphur, or chlorine.

. polymerization reaction.

bons, leaving a small amount of residual carbon. and ash. The activated coal particles undergoing decomposition behave as a highly eiiicient promoter for the polymerization of gaseous hydrocarbons while furnishing active molecules or free radicals which conjointly are subjected to the Suitable apparatus for the described procedures are shown in the accompanying drawings in which:

Figure 1 illustrates diagrammatically in crosssection a preferred type 'of gas generator apparatus for'use in the batch procedure;

Figure 2 illustrates diagrammatically in crosssection a preferred means for the continuous treatment of powdered coal.

Referring to Figure 1, the apparatus in its simplest form may consist in one or more gas generators, A and B, together with useful appurtenances. The generators have connections to vapor and gas product recovery systems of well known types used in conjunction with gas plants and petroleum refining units. For maintenance of service, preferably two or a plurality of generators are used' conjointly. A number of generators may be used also in series. An efilcient cooperation is obtained when the generators perform in alternate periods of the treatment cycles.

The generator or reaction apparatus in its simplest formis constructed merely of a steel shell I lined with fire brick 2, provided' with grate 3 or similar means for supporting a coal bed l, a coal charging means 5 with a closure therefor 6', ash pit 1 beneath the grate 3, ash discharge means 8, and with devices for admitting and withdrawing gaseous fluids.

Each generator is provided with conduits 9 through which-hot combustion gases are supplied to the underside of coal beds y4 and with outlet conduits I0 and II for removal of gaseous fluids.- Inlet pipes -I2, I3, and I4 are disposed atthe bottom of each generator for injection of hydrocarbon reactants, steam, and air. respectively. Conduits 9 .and .I0 are interconnected through a manifolding conduit I5 whence they branch for diverting the flow of hot gases withdrawn from one generator into a second generator. This arrangement accomplishes a desired passage of hot gases, for example, when hot gases withdrawn from generator A through oiftake conduit IIJ having valve I6 open, valves I'I, I8, I9, 20, 22 and 24 being closed, are passed via manifold conduit I5 into the base of generator B through the open valve 2I of conduit 9, `flue outlet II from generator B being open. The conduits II lead through valve I1 or 23, whichever one is open, from the generators to a flue gas main which may lead to any conventional heat recovery system (not shown). With valves I1 and 23 closed conduits II lead gaseous hydrocarbon products or water gas to their respective recovery systems (not shown) through valved connection 25 and 26.

To illustrate the operation of the process with reference to the apparatus described in Figure 1,

. lnery or eld gases, such as natural gas.

riod of its cycle may be injected through conduit 9 into a fresh bed of lcoal 4 charged into generator A. Hot combustion products may otherwise be produced below the coal bed 6 in generator A by combustion of hydrocarbons with air injected through inlets I2 and I4. Hot combustion gases preferably containing some free oxygen at a temperature of about 900 to l800 F., are blasted through the coal bed to quickly heat the coal to above 800 F., and thereby initiate coal distillation into high temperature products such as volatile cyclic hydrocarbons boiling in the motor fuel range. The waste heating gases are withdrawn through an open connection to conduit il. 'This preheating is preferably limited to separate less than of the volatile matter in the coal.

In the second stage of the operation the high temperature distillation of the coal is maintained at a temperature in the range of about 1000" to l300 F., or higher, when highly heated hydro-- carbon gases in place of the combustion products next are lead into the coal bed from inlet l2. These'highly heated hydrocarbon gases are preferably reactive products resulting from a thermal cracking or a dehydrogenation of regeneral, the highly heated reactive hydrocarbon gases are obtained from hydrocarbon mixtures composed largely of ethane, propane, butane, etc., by a high temperature conversion which transforms substantial amounts of the paramnic hydrocarbons into 'straight and branched chain olenns.

'I'he following table shows the olefin content of a typical product from thermally cracked par afnic hydrocarbons:

- Percent Ethylene--. 'l Propylene 2l Normal butylene 13 Isobutylene 8 Amylenes 5 ization products being formed through direct heat transfer from the gases, the reactive hydrocarbon Vgases vare given time and inducement to undergo polymerization. Volatiles released from the coal react as nascent hydrocarbons while porous -coke being formed acts as a catalytic adsorbent contact mass. Hydrocarbon products comprising motor fuel polymers, aromatic volatiles, and fixed gas are recovered by being withdrawn through conduit Il to the open connection 26 which leads to any suitable fractionating and motor fuel distillate recovery system.

When the solid fuel has been exhausted in the polymerization and distillation, as indicated by the decline in yield, the next stage of the cycle is started preferably after a short purging of residual volatiles from the coke bed by a blast of steam injected from valved inletl I 3. Following this final removal of volatile hydrocarbons, the coke bed is blown with air from valved inlet I4 to cause combustion in the lower part of the bed,

resulting in elevating the temperature oi' the l coke Abed substantially to incandescence.

The hot combustion products formed from the burned coke are withdrawn from generator vA through conduit l0 at a. temperature above 1500 F., and at this temperature may be passed directly through manifold l5 and inlet 9 to the base of generator B for use as a hot blast of gases to preheat a fresh charge of coal therein. At incandescence the elevated temperature of the coke is conducive to water gas formation,

and in the following stage, steam is injected from i valved inlet i3, about .25 to about 2 pounds of steam being used per pound of coal initially introduced, the coke bed being, for example, about twice the depth of the ash layer upon which it rests.-

The water gas products may be removed from generator A through conduit Il to an open connection 25 which leads to a recovery and storage system. As an alternative, the water gas may be passed as a preheating gas first through a coal bed in another generator in series.

A final stage of treatment which may be used in generator A is obtained by directing hot hydrocarbon vapors from a vapor phase cracking coil through the ash bed remaining from the water gas generation. The hydrocarbon vaporsl are introduced into the generator by valved inlet l2 which may be joined alternately with a conventional type of cracking coil for high boiling formed therein. 'Ihe hot combustion gases pro-,

duced during the air blowing stage being used similarly, as described, to preheat a freshcharge of coal in generator A.

A convenient modification and additional rfeatures of the invention are best described by reference to Figure 2, which illustrates means for continuously pretreating the solid fuel or coal before it is reacted with high temperature vdecomposition products of normally gaseous hydrocarbone and means for continuously carrying out the joint coal distillation and gas polymerization reaction.

Inv apparatus shown in Figure 2, coal in pulverized and dried condition', also substances such as -the adhesive gel materials mentioned, may be continuously fed from hopper 29 by a rotating discharge means 30 into the heating kiln 3|. A rotating helical scraper 32 is disposed in the kiln for mixing the coal with adsorbent substances such as the gels mentioned, for exposing the coal more effectively to a blast of hot combustion gases from inlet 33, and for conveying the heated substances through the kiln to outlet chute 34. The hot combustion gases are used in the manner described with reference tol Fi'gure 1 for rapidly heating the pulverized coal to above 800 F. External heating means (not shown) may be provided surrounding the kiln for obtaining the desired elevated temperatures in preheating the coal. Waste-heating gases are removed from the kiln by outlet 35. Dropping from the chute 34, the preheated powdered coal or agglomerated mixture thereof with adsorbent material may be then passed through a sealed roll grinder 36 fory maintaining the ilneness of thematerial.' The pulverized material is then passed into hopper the pulverized material, such compound being as an acidic inorganic gas as described.

The pulverired material becomes suspended in the stream of hot gaseous products evolved by the pyrolytic treatment of gaseous hydrocarbons passed through coil 4i disposed in furnace 42. Reaction tube 88' which may be .of any length adequate for completion of the reaction terminates in the separator 4l. By tangential injection and through the use of baffles 44, an emcient separation of suspended solids from the gasiform uid products is effected. Separated gaseous products may be further freed from suspended solids by filtering through a bed of massive solid material, such. as large pieces of coke, clay, or siliceous material in container 45,

on their passage through line 48 leading to fraczo tionator 41, Fractionator 41 is provided internally with the usual bubble cap plates or simllar devices for obtaining fractional condensation and with an overhead outlet 48 leading to a condenser coil 49 terminating in receiver 50. Fractional condensation of vapors is controlled in 41 to collect a motor fuel distillate in receiver 50, which acts as a gas separator. Fixed gases from receiver 50 and reflux from fractionator 41 may be recycled in the usual manner. 'The solid reaction particles which precipitate in separator 43 form a bed of finely granulated coke at the bottom thereof. Superheated steam from spray inlets 5I surrounding the separator 43 may be injected near the base to drive residual volatiles from the solid particles. At the bottomof separator 43 is disposed a rotating means for continuous removal of the coked particles which may be used as a powdered fuel for heating purposes or in other reactions, as in the production of water gas with recovery of the uncombustible adsorbent material for use in a subsequent catalytic process, such as in a hydrocarbon cracking process.

A particularly beneficial embodiment of the invention consists in accomplishing the polymerlzation of normally gaseous oleflns to normally liquid hydrocarbons in the`presence of a solid carbonaceous fuel combined .with certain inorganic compounds capable of promoting desired reactions. ganic compounds characterized by both hygroscopic and acidic properties have tendencies to become adsorbed by solid .carbonaceous materials apparently uniting therewith in the form of compounds or complexes. At any rate the substances produced by combining these types of inorganic compounds with pyrobitumens or the calcined products, such as Iare formed in the preheating treatment to whichcoal or other pyrobituminous materials are flrstsubiected in accordance with the present invention. effec- 'p'r'omote the release of volatile hydrocar- ,the hygroscopic and acidic compounds, are diffi- It has been foundl that inor-l v s from the solid fuel and induce polymeriza. tion of normally gaseous hydrocarbons in their ,ssaom cult to analyse. However, with the oxides of phosphorus, organic compounds present inthe calcined'coal may be said to become phosphated even though the phosphorus is considered to exist in several states of oxidation under the reaction conditions. For example, even if elementary red phosphorus or lower oxides of phosphorus are usedsome oxidation may occur at the elevated temperatures with the presence of oxygen compounds to produce higher oxides and on the other hand, higher oxides of phosphorus tend to be reduced as they react together with hydrocarbons or carbon monoxide. These factors establish the likelihood that the phosphorus oxides regardless of their initial composition ultimately become altered so that the phosphorus is combined with oxygen in ratios corresponding to the following compounds:

P0: and its polymers P204, P40 and the like in equilibrium with PzOs o r its polymers.

In a similar respect oxides of sulfur used to activate the calcined coal may undergo changes of oxidation or reduction under 'the reaction conditions and accordingly be said to either sulphonate or sulphate the organic compounds present in the solid phase during the destructive distillation of the pyrobitumens contacted with the reactive hydrocarbon gases undergoing polymerization.

Anhydrous metal halides, particularly aluminum chloride, although other Friedel and Crafts type catalysts may be used including halogen compound of various other metals e. g., tantalum tin, antimony, etc., appear to form various complexes with the solid phase pyrobitumens and similarly act as a, promoter. The pyrobitumens may be additionally chlorinated and used as such or with a metal halide acting as a. hygroscopio acidic compound.

Obviously each of the particular activating compounds will have its own peculiar action in causing the pyrobitumens to become decomposed and in bringing about interaction between the reactive hydrocarbon compounds brought into their presence. `In some cases it is desirable to use a mixture of the activating compounds, for example, both oxides of sulphur yand phosphorus.

Commercial adaptations of the process have been well exemplified in both batch and continuous treatments of oleilnic gases conjointly with solid carbonaceous fuels for the production prinaily of high anti-knock liquid hydrocarbon ue s.

To summarize, the principal products obtainable by treating solid carbonaceous fuels in acsordance with the described process are as folows:

1. High octane number motor fuel ingredients composed of gaseous olefin polymers and cyclic y hydrocarbons derived from destructive distillation of solid fuels.

2. A high pressure water gas -of high heat content suitable for use in syntheses involving hy- 'lrolgenation of carbon monoxide or for use as 3. The production of a valuable powdered fuel.

4. The formation of an emcient catalyst for hydrocarbon conversions including polymerization and splitting reactions.

While specific embodiments of the invention and systems for carrying them into practice have been explained by way of illustration, it is to be understood that this invention is not to be. confined by the exact steps, pressures, temperatures,`

velocities, proportions, materials or particular devices mentioned herebefore as typical or representative. For instance, various solid carbonaceous fuels from which volatile hydrocarbons can be derived by destructive distillation can be considered as equivalents of coal, such as oil shales,

, lignite and various types of coals. Various other 1. A'process for producing liquid hydrocarbons from solid carbonaceous fuel under the influence of gaseous hydrocarbons undergoing polymerization, which comprises calcinating said solid' carbonaceous material agglomerated with a solid inorganic adsorbent gel in a finely divided form to above800 F. to convert the carbonaceous material into solid pyrobitumens, separately heating a stream of normally gaseous hydrocarbons under a superatmospheric pressure to a temperature in the range of about 1000 to 1350 F. for a time suicientrto activate the hydrocarbons by dehydrogenation, mixing said solid pyrobitumens resulting from the calcination with the thus activated gaseous hydrocarbons to eect polymerization of the hydrocarbons and destructive distillation of the solid pyrobitumens in a dry solid state, removing vaporous reaction products, and condensing a gasoline motor fuel therefrom.

2. A process for producing liquid hydrocarbons from solid carbonaceous fuel under the lnuence of gaseous hydrocarbons undergoing polymerization, which comprises calcinating said solid carbonaceous material in a finely divided form to above 800 F. to'convert the carbonaceous material into solid pyrobitumens, activating said solid pyrobitumens by treatment with a hygroscopic acidic inorganic substance, separately heating a stream of normally gaseous hydrocarbons under a superatmospheric pressure to a temperaturein the range, of aboutlOOO to 1350 F. for a time suflicient to activate the hydrocarbons by dehydrogenation, mixing said solid activated pyrobitumens with the thus activated gaseous hydrocarbons to effect polymerization of the hydrocarbons and destructive distillation of the solid pyrobitumens in a dry state, removing vaporous reaction products, and condensing a gasoline motor fuel therefrom.

3. A process of polymerizing4 normally gaseous olens to produce normally liquid hydrocarbons which comprises subjecting said olefins in` the vapor phase under polymerizing conditions to the action of a. calcined pyrobituminous material agglomerated with a solid inorganic adsorbent gel and activated with a hygroscopic inorganic compound while said calcined pyrobituminous material undergoes dry distillation.

4. A process of polymerizing normally gaseous olens to produce normally liquid hydrocarbons which comprises subjecting an olen containinggas in the vapor phase under polymerizing temperatures and pressures to the action of pyrobitumens agglomerated with an adsorbent siliceous material and treated with an oxide of phosphorus said pyrobitumen being partially distilled and undergoing carbonization in a dry solid condition.

CECILIO L. OCON. ERNEST A. OCON.

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