US2390031A - Hydrocarbon conversion - Google Patents

Description

NOV' 27, 1945 A. H. scHuTTE ET Al.

HYDROCARBON CONVERSION Filed Dec. 14, 1945 Abon" residualssise red Patented Nw. 21, 194s A v www .Xedphse'iand ether-r ,idesiredyfobjectand improved rnethod `for treatment ofthe end of the processsinceithev cokelyformed inthe carbons,andktarset es'pec'illyfthose hih are process,imayzbeiuseipthereaitergfforgfthe produc- .residuesfofvaricuwycommercial-processes. g 'if f-utherma'l; renelgyi 1as1;'wi l1.`..clearly appear f-rllIt is=fa` p`a`rlt'licl`11:`trl object of this invention tofffii treating f vous, etc., .xreduced-zcrude which isf'agresidue-of .aycrude oil stopping;,operationorrativacuum y reduction-operation, or a cracked residualffrom,acracking.op- OXLJ efeiringitoithedrawing;illustratingdiagramfimaticallmeandwpartly;in.section;fapparatusadapted to the accomplishment ofithiScinvention,:the

whereby to secure or recover vaporous'or gaseow as an additional valu It "isiwfprtfl leutiron to l5.A provide such a method wherein improved re-l" z2 ('wl'iic mambeftermednthe 1,,-I.,ea,ction chamturns from the conversie eavylyhyrocarf- "eavytihydiccarhonfchargefisinjected he production -of oncurrent, with-afmovinabed: oflheated rg instance, :asoli `A`A`,par-ticle l:(etheriporous'fQrTsubstantially Contact material;` '(suchi asili inert refractory,i rackngvtcataiystfol:coke) yor spread vunion there artcl surfaces thereofttorproduce condensibiei-apo and;cnoneccnderisihlergases to prowhich` are:iremoye-dtfrornf1th dlpner'endthe coke fingadditilqn to i" this'inv 1:Vide -a new andimprovedcontinuous cokingh25areactiomchiamber;Zeabovegtheibedawhile theybed mei-.lloclw` whereinfsxparticlesi Qfae'cfontacty;Il'laterialfi? particles are coated with dry' fzcoke.=g,The coke- [object to suppl He ac coated --fbedfrparticles a are, removed f continuously Afrom tlielowerftend .ornthepreaction chamber 2 and replacedaby new lor regenerated l`hed Aparticles '-introducedminto', the4 upper;rendiioffthev` reaction h In various crackin i l utilizingfa moving ataiystfibe" Y l should exceed the rate or introduction ty the conveyor I.' This is accomplished by varying 'the capacities of the conveyors s andflaccordingly,

in order that the quantity or contact material the outlet i are received by any suitable` collecting and/or conveying means such as a chain grate, link elevator, rail conveyors, track cars or the like, designated 'I in the drawing.

Disposed in the reaction chamber 2 in the path of the bed of contact materialis one or more charge distributing members such as the spargers 8 which receive the heated hydrocarbon charge from the charge inlet leading from any suitable supply as, for instance, a heating furnace ied from a storage tank or reservoir.

Each of the spargers I vis provided with a ccntrol valve i8 for controlling the rate at which the charge is supplied and 1 spread thereby upon the bed material. This rate of injection or supply of the charge and the speed of the Vbed determine the spread density. i. e., amount of spread charge per unit of volume of the bed. Y y

'I'he speed of the' bed is controllable through variation of the speeds of conveyors I and `5 and the iniection or supply rate- (and spread density) through the valves Il. While the feed control valves il maybe manually controlled, if desired, means responsive to the temperature in the coking sone adjacent each sparger 8 may be provided. As shown, this means comprises thermostatic valve control units or members ii responsive to the thermostatic elements i2 each suitably arranged in the path of the moving bed to control the respective valves- -in accordance. with the'temperature of the bed material in that coking zone adjacent the sparger controlled through the'valve which is responsive to that element-i2. Y

Since the initial temperature ofthe bed material decreases progressivelyv throughout-ita travel through -the chamber 2, in the absence oi compensatory heating devices, the spread density or charge feed rate must decrease accordingly in such cases in order to prevent incomplete coke production or, in other words, in order that coke produced will be dry, thus avoiding cementing, chunking or sticking together of the coke-coated bed particles. By proper adjustment of the control units or members Il, this may be automatically accomplished.

While we have, herein, illustrated the provision of three spaced spargers I, forming three coking zones in the chamber 2 and substantially equidistantly spaced, any numberand any spacn ing may be provided, where desired.

With proper control of the variables, it is ccntemplated that the coke produced in the chamber be applied in superposed layers or laminae.

the upper end or the chamber 2 through the vapor outlet Il. These vaporous products comprise condensible vapors and incondensible gas or gases. These products may be carried ofi for separation and processing in any known manner, as, for instance, for removal of gasoline and gas oil by condensation and separation oil of the incondensible gas or gases.

While such vaporous products and their treatment are known in the art, it is the case, how ever, that their production concurrently with the continuous production of coke,as described above, has not heretofore been practiced.

A specific example is as follows! Charge:

Mid-Continent reduced oil, with A. P. I. gravity 60' F. of 18.0.

8.7 lbs. of (oil) charge was introduced at 840' F. to the coking chamber: spread upon 24 lbs. of bed material at 970 F. Contact time 8 minutes, 36 seconds.

Temperature of the'bed material fell from 970 F. to 870 F. v

The products comprised: Gas 0.188 lb. or 2.8% Distilltel 5.750 lb. or 86.9%

C0ke 0.5001b. 0r 1.5%

o Alternative bed material:

Calcined coke particles. l

Elize Approx. 5 mesh (average) voids a 40% (approx.)

Further investigation indicated the preferred range for the same (oil) charge to be as follows:

Charge (oil) introduced'into the coking chamber at 800 1". to 950 F. and contacted with a bed of contact material comprising chemically inert refractory particles, or coke (as above), at 900 I". to 1100 F. (providing the main portion of the coking heat or thermal energy) with a charge spread density of 5 lb, to 50 lb. of (oil) charge per 100 1b. of bed material and Contact time of 5 min. to 30 min. will produce a coke yield of 3 lb. to 30 1b. of coke per 100 lb. of

(oil) charge introduced.

It follows that where the bed material comprises calcined coke particles, the coke deposit thereon will be approximately the same and will represent increase in grain or particle size.

Particularly where thel bed material is a chemically inert refractory material, it is advantageous to employ as the collecting means 1 a chain grate or other means for using the heated output of the outlet I, before the heat thereof is dissipated. Where such immediate use is possible, the latent heat of this output is additive to the heat energy or thermal energy produced, or lib erated, by combustion of the coke coatings in the material.

.titles of the end products, may .be

desired.

The contact time is, of course, a function oi' the speed of movement of the bed 'through the chamber or coking zone and may be varied according to the nature of the charge, the temperature of admission of the charge, and of the bed material, and the rate oi' feed, or charge spread density, all of which may be varied tosuit the properties of the charge as well as the types and relative quantities of the end products desired, in a manner well known inthe art.

The nature of the bed material likewise may varywith consequent effect on the above men-r tioned variables. It may comprise a chemically inert refractory material, a known cracking catalyst material, or calcined coke particles which are enlarged by the deposit of coke coatings or envelopes thereon according to the principles o! this invention. Therefore, the inclusive orfcomprehensive term contact material as used herein is of substantial scope since it covers these three rather divergent types of coke deposit receiving media. v

The term calcined as herein applied to the coke comprising the bed particles refers to coke for the heat exchangers or heaters it.

lSince itis much easier to secure a dry coating when the thickness thereof is slight, and since l the dryness or non-tacky nature of the deposited coke is important in preventing the formation of lumps, clumps and cementing in the bed, the above described "multiple coating" principle is an important feature of this invention. 'the cca-tings secured on the bed particles or nuclei dry, non-tacky, brittle, and frangible whereby the movement of the bed is sumcient to maintain the coated particles separate from one another, or discrete within thebed, without necessity for the provision of mechanical agitation or stirring.

The above described independent control ot the est in th'e iirst or upper coking zone, the charge particles from which volatile matter has been rebut a single coking zone, wherein but a single coating was deposited on the bed particles, the yield maybe greatly increased by applying the coke produced in the chamber yas a multiplicity of coatings or superimposed envelopes, each indi. vidually relatively thin but collectively of substantial thickness. y'lhis "multiple coating is effected, according to this invention by dividing the coking chamber into a multiplicity of coking zones wherein the charge feeds and/or spread densities are independently controlled, according to the temperature of the bed material in each zone.

Optionally, means may be provided for in e-l pendentiy controlling the charge temperature according to the bed temperature, independently, in each zone. This means may comprise independent heat exchangers or heaters I3 for each sparger t controlled either by the control means il, I2 of each sparge! or by functionally similar heat responsive means comprising individual, independent valve control -units or members I! re sponsive to the above described thermostatic elements I2, as shown. Independent thermostatic elements (not shown) may be provided and lo- A cated if desired.

its shown, theheat exchangers i8 mayl com prise elements of conventional form to which heating gas or fluid is supplied by conventional feed pipe 29, having common connection therewith, under control of valves 2| operated by the above described control units it, a suitable exadmission temperature would be lowest while the charge admission temperature should be highest in the iinal coking zone or lowest coking zone where the bed temperature is lowest. Also, in apparatus provided with multiple coking or reac tion zones, by use of the above describedcompensatory means, the spread density in each zone may be maintained equal.

It is, of course, to be understood that th'e above description is merely illustrative and in nowise limi-ting and that we desire to comprehend within our invention such modifications as are included within the scope of the appended claims.

Having thus muy described our invention. what we claim as new and desire to secure by Letters Patent is:

l. In a method of recovering usable thermal energy from heavy hydrocarbons, passing by gravity through a sealed chamber including a plurality oi' coking zones at predetermined/speed, a preheated bed comprising' particles of solid con tact materiaLspreading on said moving bed in each coklng' zone a heated heavy hydrocarbonl charge at predetermined spread density and at predetermined admission temperature, while independently controlling the temperatures of admission of said charge to said chamber and the spread density of said charge in each ofsaidcoking zones to compensate for temperature drop in said bedin its passage through' sai'd zones, whereby to form on said bed particles in each colringl zone coatings oi' dry non-adhesive cokecapable of combustion for generating thermal energy up-- `on use of said coated bed particles as fuel.-

2. In apparatus for converting hydrocarbons, means forming a reaction chamber, means for conveying a bed comprising heated particles of contact material introduced at a predetermined temperature through said chamber at predetepmined speed, means for injecting a heated hydro-v carbon charge at predetermined spread density into said bed at a plurality of points in its path of travel through said chamber for forming vaporous hydrocarbon conversion products and depositing a plurality of superposed dry coke coatings on said bed particles, and means responsive to the bed temperature for independently controlling the charge injection rate at eachof said points of charge injection to compensate for variation in bed temperatm-e by varying the spread density directly with the bed temperature mustn being provided, in conventions manner,

wh'ereby to prevent incomplete coke production throughout said chamber.

3. In apparatus for converting hydrocarbons, means forming a reaction chamber, means Afor conveying a bed comprising heated particles of contact material introduced at a predetermined temperature through said chamber at a predetermined rate, means for injecting a heated hydrocarbon charge at predetermined spread density trolling the charge injection rate and the charge injection temperature at each of said points by varying the charge injection temperature inversely with the bed temperature and the ch'arge spread density directly therewith whereby to secure uniform coke coatings and compensate for into said bed at a plurality of points in its path 10 variations in bed temperature. of travel through' said chamber for forming vaporous hydrocarbon conversion products and de- AUGUST HENRY SCHUTTE. VFRNON O. BOWLES.

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