CA2128434A1 - Fluorination of catalyst and process - Google Patents

Abstract

A chromium-free fluorination catalyst comprising an activity-promoting amount of zinc supported on an alumina, halogenated alumina or aluminium oxyhalide support and use of the catalyst for the production of fluorinated hydrocarbons by reacting a hydrocarbon or a halogenated hydrocarbon with hydrogen fluoride in the vapour phase in the presence of the catalyst.

Description

WO 93/1~79~3 1 PCI/GB93/00244 YLUORINATION CATALYST AND PR~CESS ' ~1284~3~4 This inven~lon relates to an i~proved fluorinat~on c~tal~st and to a proceg3 fo~ the production of flu~rln~ted h~drocarbons b~ the cat~lyssd re~ction of hydrocarbons and haloge~ated hydrocarbons ~ith h~droge~ fluor~de. The in~2~t~0n relates ~n particulnr tG a promoted alumin~, ~alogenat~d alum~a or alum~nium o~yhalld~ catal~st a~d relates 1~ a p~rticular embodiment to a prooe~s for the productlon of 1,1,1,2-tetrafluoroetha~e b7 the cnt~l~sed re~ction of l-chloro-2,2,2-tetr~fluoroeth~ne ~ith h~drogen fluvrlde.
The productlon of fluorl~ated h~drocarbons, which may also contain halogen ~toms other than fluor~ne, by the c~talysed ~apour-pha6e fluorinat~on of hydroc~rbon~ a~d halogenAted hydrocarbons ~lth hydrogen fluoride i~ well k~own and ~umerous cstal~sts ha~e been propo~ed for use in ~uch process. Catalys~s comprisi~g or based on ehro~um and in particul~r chromia are freque~tly emplo~ed in ~he ~o~n ~: proc~es. Purthermore, it h~s al~o b~e~ proposed ~o promote the act~v~ty of ~hese chromium containing cat~ly8t8 b7 the ~corporation 1~ ~he cetalyst of an act~lty promoting amoun~ of certPin metal~, for e~ample zinc, nickel, cobalt ~ ; and mangane~e.
:~ Thus, for e~mple chromia or B haloge~ated chromia may : ~be u ed in the ~apour-pha6e reaction of trlchlorDeth~lene:; 25 with hydroge~ fluoride to produce cbloro-2,2,2-trifluoroethane as de~cribed ~n G~ P~te~t 1.30~,224 ~nd ~n ~he ~apour-phase reac~on of ~.
chloro-2,2,2-trlfluoroethane ~lth h~drogen fluoride to ; produo~ 2-tetrafluoroethane ~ de3er~bed ~ GB Paten~
:1,589,924. The ~me cat~ly~t m~y be u~et for the flluor~ation of chlorodlfluorethyle~ to chloro-2.2,2-trifluoroethaae. GB P~ten~ 1 ~ 5~ 9, 924 ; de~cri~s ~he re~oval of chlorodlfluoroeth~le~e impurlty rom 1,191,2-~et~fluoroethane b~ re~c~ing the impur~t~ ~ith h~drDgen fluo~de~

WO93/1679~ - 2 - PCT/GB93/00244 Cat~ly~ts ma~ also comprise chromium upon a metal o~ide, halogenated o~ide or o~yfluoride support, for e~ample alumina or magnesia, and during the fluor~n~tion prDces~ in whlch the c~tal7~t i~ employed, the chromium may be converted to chromi~, halogenated chromla Dr a chr~mlum o~fluoride. It has now been fou~d that ~hil~t i~ the ab~ence o~ chromium, the~e supports ~how very little catalytic ac~ity alon2. some support~ may b~ glve~ ~
Big~ifiCant acti~ity by the lncorporat~on of an ACtiYity promo~ing a~ount of zinc.
Accordl~g to th~ present invention there ~8 pr~ided a chromium-f~ee fluorlnation catalys~ compri~lng an ac~lvity-prQmoting amount of zinc or a compound of zinc 8uppor~ed o~ an alum~a, halogenated alumina or aluminium o~halide support.
~ ccording ~o the inYentl~n a1~Q there ~ provided a proce~s for the productlo~ of fluorislated hydrocarbon~ which co~prises Y~aCt~I~g a hydrocarbon or R halogenated .

:~ hydrocarbon ~l~h hydrogen fluor~de in the ~apour phase ln 20 ~che presence of a fluorin~tlon catalg~t aB defiD.ed in the amediately preceding paragraph.
: The amount of z~nc ~ncorpor~ted in the catal~st is 6uch s to result ln promot~on of the actiYity of the alumina, haIogens~ed alumina or aluminium oYyhalide in~4 which the zinc promoter i5 incorporated. The amount i8 important sincP
;the incorporation of too much of the zinc promo~er may e~ult în a decrea~e r~ther than an increaBe i~ cat ly8t act lt~ when compared to the acti~ity of the catal~s~ when ~he Gpt~mum ~mount of z~nc pro~oter ls i~corporated and it i~ onl~ when the z~c promoter i~ pre~e~ the CQrrect ~ount that optimum act~vity promotion occurs.
: The amount o~ zinc promoter i~corpor~ed 1~ the catal~8~ to ach~eve ~g~ificant ncti~it~ promotio~ w~11 depe~d upon the basi~ support emplo~ed, i~ phrtioular the ~urface area of the ~upport and upon the ~eehod u8~d to WO93/1679~ ~ 3 ~ PCT/GB93/00244 8~3~
prepare the improved cgtglygt. However. for any p~rtlcular ~uppor~ and ca~lygt preparatlDn method, the op~imum RmOunt of zinc promoter i~ readily det~rmined b~ ~imple routine eYperimen~. Overall, the amount of zi~c will usuall~ be in the range from about 0.5~ to about 302, and preferably from about l.5~ to about 25I b~ ~eight of the cataly8t.
The optimum a~ount of zinc incorporated depend~ on the Burface rea of the cataly~t, in particular the ~orking surfac2 Area of the cat~lyst'. The working surface area of the catal~8t ls the ~urface area of the cat~ t mea~ured af~er c~taly~t prepara~ion and pre-~reatment ~lth hydrogen fluoride (as deacribed hereafter) or, if the c~tsl~st 1~ ~ot pre-treated with h~drogen fluoride, after the c~taly6t ha~
been'employed in a vapour phase fluor~na~ion reaction in which h~drogen fluoride ~ 8 emplo~ed. The worki~g ~urface area of ~he cataly~t may be ln ~he range fro~ about lO to about lOOm2/g, t~pically from about 10 to 3bout 50 m2jg.
Where the catalyEt i8 prepared from alumi~a, al~mi~a ~th a sur~ce area of from about 50~2lg to about ~OOm2Jg~ ~i~es a c-talys~ after preparation and pre-treatment with a worktng urface are~ ln the defined range. The catalyst ma~ be prepsred from starting aluminas having a surface srea from about 50m2~g to about 250m2/g and pre~erably from ~bout lSOm2/g to abou~ 250m2/g.
t~ted abo~e, the amount of pro~oter i~corpsra~ed in the cat lyst al~o depe~ds upon the catal~t preparation employed. The çffecti~ p~rt of the catal~st i8 belie~ed to be the surf~ce o~ the ~upport contain~ng zinc promot2r c~tions loea~ed in an alu~in halogenated alum~a or aluminiu~ osyhallde latt~ce and it ls t~e amount of ~uch suirface zinc promo~er wh~ch determ$nes the sctl~t~ of the c~alrs~. The actl~ity-p~o~oting effect of the zine pro~oter per unit weigh~ of t~e zinc promoter l s gene~all~ higher for catalyst3 ~ade b~ l~pre~nation than for catal~ts m~de bg ~ 35 W093/1679X ~ 4 ~ PCT/GB93fO0~44 3~ .
other method~ snd conta~ning the zinc promoter in non-surface locations.
By w~y of esRmple, in the case of zinc incorporated by impregnatlnn on an alumina support, the alumlna u~ed to prepare the catalyst having a surface area of 180m2~g, opeimum actl~i~y promotlon results ~hen the amount of zinc is w~thi~ thc range of about 0.5~ by ~eiBht to about 10~ by weight of ~he cataly~t, preferabl7 ~i~h~n the ra~ge from about 0.52 to about 6Z, more preferably ~ the range from 10 about 1.52 to about 4Z a~d espec~ally $n the ra~8e f rRm ~sbout 1.5~ to abou~ 3.52; less t~an 0.5~ b~ ~elght of z~ac may be $nsuffic~ent ~o result in s~gnifioant promot~on of catalyst activity whil~t morc than about 8~ by welght of zin~c msy result ln no signiflcant lncre~e in catalyst activi~y whe~ co~pared ~o the activit~ promot~on provided by the above optimum ranges of z~nc. B~ contrn~t, in the ca~e cf a catalys~ prepared by co-precipit~t~on and ln ~h~ch Signi~iCBn~ amounts sf zi~c are i~corporated in non-~urface :: loca~ions, the ~ount of zinc may be withi~ ~he ra~ge from bout 3~ to about 302 by ~eight of the c~t~l~st, preerably from abou~ 4~ ~o about 25Z by weigh~ of the cataly~t, e~peciall~ from about 52 to about 15~ b~ we~ght of the ~: atal~st.
The zlnc promoter ma~ be incorpor~ted ~n the catal~st

2 in ~he form of 8 co~p~und, for e~ample a halide, o~yhal~de, oxide or hydroside depending at least to aome e~t~nt upon e~cataly~t prep~r~tion tech~ique e~plo~ed. In the c~6e ~: : ~here catal~t preparation i8 by impreg~at~on of alumi~ium ::
~: oxlde, h~log~na~et sluminium oxide or sl~ml~ium o~hal~de uppo~ he co~pound i~ prefer~bly a w~ter~oluble sslt, or esample ~ h~lide, ~itrate or a~etate~ and i~ e~ployed as its zqueous ~olution. The h~dro~ide~ Of the pro~oter and ~lu~inium ma7 be co-precip$~ated 8~d the~ co~rted ~o the o~ides to prepare the catal~st. ~ ng ~d ~illing of ~ zoluble zinc ~o~pou~ds with t~e baælc catalyst provides a ; 35 W093/1679X ~ S ~ PCT/GB93~00244 further method of prepari~g the c~taly6t. A method for m~ki~g cat~l~st~ based on aluminium o~yhalide compriYe~
addl~g a compound of the promoter ~o hydrated aluminium fluoride ~nd calcini~g the mi~ture.
An7 of the aforementio~ed methods or i~deed other ~ethod~ ma~ be employed for the prep~ration of the zlnc promoted c~ly8t8 of the present inventio~.
The fluorlnation catal~8t ~ill u~ually be sub~ect~d to a prefluori~at~o~ treatme~t ~ieh h~drogen flusride a~d optionally a~ ~nert diluen~ prior to use i~ the cat~l~s~ of fluorinatlon reaction~. A t~pical pretrestme2t compr~es hest~n8 the catal~st at 250C to 450C in contact with hydrogan ~luoride, or a mi~ure of hydrogen fluoride and air~ Co~6equently the worki~g catalyst is believed to be at ~: 15 lea~t par~iall7 zi~c 1uoride sl~pported on fluorinated alumina or aluminium osyfluoride.
The catal~t ma~ be used in the form of pellet~ or ~: granu}es of appropriate size for uBe in a fi~ed b~d or a ~: fluidis~d bed. It may be regenerated or re~ctivated ~ 20 periodicall~ by heatin8 in air at ~ temperature of from -~ about:300C to about 500C. Air ma~ be used a~ a ~isture with an inert gas such as ~itro~en or with h~drogen fluorite ~hich emerges hot from the catalyst treatme~t proces~ and may be used directl~ in Yapour phase fluori~a~ton processes.
The actlvity of the base (unpromoted) slumina, halogenated alumina or aluminium o~yhalide catalyst ~ E
enh~nced by ~he l~csrporation of the promoter. The selectiYity of ehe reaction catalysed by th~ cntsly6t to~ards the productio~ of 1,1,1,2-tetrafluoroeth~ne from ~; 30 1-chloro-2,2,2-tr~fluoroethane and hydroge~ ~luoride ~a~ be nt lea~t ~s high a~ that u~ing the corre~ponding unpromo~ed cst~ly~ts, t7picall~ ln e~c~as of 852.
If desired, t~e o~talyst ma7 co~t~in on~ or fflor~ ~etals o~her than æ~nc, for e~ample nickel, copper t ~ga~e3e, cobalt, and ir~ nd ~n particulsr iron, cobalt a~d copper WO ~)3/1679X - 6 ~ PCr/C~B93/0024 r since the pres~nce of one or more of these met~ls may e~h~nce the e~tent to ~hlch catal~t act~v~t~ may be restored by regenera~ion of the c~talyst. At the particularly preferred loading~ of z~nc, ~e ~enerally prefer to employ only zinc or at lee6t predom~nan~l7 zinc, with only small amounts, 8A~ less than 2.0~ by ~eight, preferably le~ th~n l.S2 by ~ight ~nd especlall~ le~8 tha~ 1.0~ by ~eight of o~her metals prese~t. ~here ho~e7er, the oatAl~st compri~es ~ relatiYely h~gh lo~ding of ~i~c, s~y for e~ample 10 ln the csse of a o~taly6t prepared by i~pregnation, greater than about 3~, preferably gr~ater t~an about 4~ a~d e~peciall~ gre8ter than about 5Z by ~elght ~l~c, we prefer to lncorporate ~all amou~t~ of ~ron, ln pare~cular, ln ~ddition to zlnc, for e~ample to ~ncorporate ~n amount of 15 ~ron in the range from about 0.1~ by u~ight to abo~t Z~ b~
welght, preferably from ab~ut 0.1~ by weight tG ~bout, 1.5~
by weight and more pref erabl~ from about O . 5Z to about 1. 52 by weight of t~e catalyst. The ratio ~wtZ ha~ed osl the ~elght of the catal7st) of zlnr to iron i6 pr2ferRbl~ in the ran3e from about ~0:1 to about 2:1~ more prefer~bly i~ the ra~ge from about 16:1 to about 2:1. This ratio i~ preferred irre~pec lve of the sbsolute nmounts of zinc a~d iron ln the catalyst.
Thus, although the absolute amounts of zinc and iron ma~ be higher, for e~ample at least 6Z, preferably at least lOZ:zinc by weight of the cat~l7st, and an amou~t of iron in he r~nBe from ~bout 0.~ to about 121, preferabl~ from bout 0.4Z to about 4.52 by weight of the ca~al~t, i~
respect of cataly8t8 prepared b~ met~od~, ~or esample co-preeipi~io~ which lead to significa~t ~mou~t~ of z~nc nd iron bel~g l~corporated in the cat~lyst i~ ~on-~!urface loc~tiuns, the relative amounts of zi~c and ~ro~ (~tZ bssed on the weight o~ the catalystj i~ al~o preferabl~ ~ith~n :
~; the ranges given above.

: 3~

W093/1679R PCT/GB93/~024~

L?l; 3 ~
~ further feature of the invention re6ides in use of the promoted cAtal~st ln fluorinatlon pr~ces~es comprlsing re~ction of a hydrocarb~ or hal~genat2d hydrocarbon with h~dr~gen fluorlde in the ~Rpour-ph~se.
Alkenes ~uns~tura~ed h~drocarb~ns) and i~ particul~r h~lo~en ted al~enes, for e~ample trlchloroeth~le~e or hal~genated alkaneg of 1-4C atoms prefer~bly co~t~i~lng at least o~e chlorine atom ma7 be fluorlnated and examples of specific fluori~ations which ma~ be effected are the production of 1,1,1,2-tetrRfluoro thane from l-chloro-2,2,2_trlf 1UOEOe~ha~e, the production of chloro-2.2.2~rifluoroet~ane from trichloroe~hylene and the conYersion of l-chloro-2,2-difluoroethylene tD
chloro-2,2,~-tr~fluoroethane. Esample~ of o~her fluorination r~actions in which the catal~st 18 useful are the reactlon of perchlorGethylene with hydrogen fluoride in v~pour phase to produce dichlorotrifluoroethene (123), chlorG~erraf~}uoro~thaDe (124) ~nd~or pent~fluDroethane (125), and t~e reection of perchloroethyle~e with chlorine a~d hydroge~ fluoride ~n ~apour pha6e ~o pr~duce trichlorot~ifluoroethane (113), dichlorotetrafluoroethane (114/114a) andlor chloropentafluoroth~ne (115~.
The:fluorlna~ion condition~ employed ma~ be tho6e known to be~ u~eable when employi~g chromiA or halogenated chromia a6~ the~catalyst, for e~ample atmospheric or superatms~pheric pres~ure, hydrogen fluoride and temperatures in the range of 0~~C to about 5~0C depending UpG~ the p~rticular 1uorination resction b~ng carr~ed~o~t.
oweYer ~ the incre~sed activit~ of thæ promoted c-tal~st p~rmits react~ons to be carried ou~ without lo~ 6 of ef~iciency at s~gnificantly lower temperatur~ tha~ those r~quired to achlsve ~imilar actiYit~ U8i~g the unpromoted :lumina. ~or Qsample whll8t ~i~lds o~ o~l~ O.S2 I,l,l,Z-tetr~fluoroethanz from l-ch~oro-2,2,2-t~lusroethane may be achieYed at ::~ 35 :;

.

. WO93/16798 P~r/~B9~/0~244 X~L~B~3~
atmospheric pr~ssure when using the relstively high te~pera~ure of 360C or above ~hen u~ing unpromoted al~mina, a lo~er temperature of ~ay ~80~C i8 ssffic~e~t to achieYe grea~er resc~on efflcie~c~ u8ing a ~inc-promoted ~lumina.
Alternatively, lf the temperature i~ the same, 8sy 300C, a ohorter contact time i8 required u8ing the pro~oted ca~alrst .
A preferred embodlment of the process of the ~nvention reside~ in R prooess for the prep~ratlDn of 1~ 1,1.1,2-tetrafluoroethane ~hich co~pri~es reacti~g 1-chloro-2,2,2-~rlfluoroeth~ne ~ith hydrogen fluoride ln the ~apour phs~e in the pre~e~ce of the promoted catalyst of ~he in~ention. T~$~ proees~ ~y be csrrl2d out under a~mospheric or s~peratmo~pheric pres~ure at a temperature of rom abDut 28~~ to 5~0C.
The proces~ may be one stage of a t~o or three-sta~e proce~6. for esa~ple ~t mny be ~he seco~d B~age o~ a proce~
for t~ produc~ion of 1,1,1.2-tetrafluoroethane from richloroethylene, the fir~t fit~ge bei~g the vapour phsse fluorination of trlchloroethylene with hydrogen fluor~de in the pr~sence of a fluorlnation catalyst to produce c~1O~o-2,2,2-tr~fluoroethane. The promoted catalyst of the inventlon may be used i~ the fir~t ~t~ge a~ ~ell as in : the seco~d ~tage of thiE two-Btage proces6. Typlcal re~ction condltlons for the the flrst ~tage are ~tmo~pheric or uperatmo~pheric pres~ure ~nd a temperature i~ the range of bout 180C tD ~bout 400G.
The prQduction of l.l,l,~-tetr2fluor~eth~n~ from chloro-2.2,2-tr$fluoroethane re~ults 1~ a pr~duct 6tream co~ai~ing the toxic $~purit~
chloro-2,2~-di~luoro~th~lene. Th~ i~purity c~n be re~oved by reactl~g it wi~h h~droge~ fluoside 1~ ~h~ vapour pha~e tn . ~ , th~ presence of a fluorl~atlon r~ 8t at ~ t~mp~r~ture b~low about 270C. ~or ~sample 150C to 270C. ~he pro~oted catal~st o~ ~he ~nventlon ma~ be emplo~ed in this reaction, WO93/16798 ~ 9 ~ PCTJG~93/00244

3~

thus providing a t~ree-stage process for the prep~ration of 1,1,1,2-tetrafluoroethane essentially free from l-chloro-2,2-difluoroethylene from trichlorueth~lene using the promoted c~t81~st in one or more of 4ach of the ~hree reaction stage~.
~ particulsrly preferred embodimen~ of the abo~e~describ~d tw0-8tag~ proces8 for prep r~ng 1,1~1,2-tetrafluoroetha~e from trichloroethylene co~prl~e~
the steps of: -(~ oontact~ng a m~sture of l-chloso-2,?.2_trifluoroet~ane and hydrogen fl~or~de ~ith fluor~nation catalyst at a temperature $~ the ran8e from about 280 ~o about 450~C in a first reaction zone to ~orm a produc~ cont~ing 1.1,1,2-tetrafluoro~ehaae snd hydrogen chloride toge~her with unreacted st~rtl~g material6, (B) pA~ing product of ~tep A together ~ith ~rlchloroe~h~lene to a second reaction zo~e contain~g a fluori~ catal~st at a tempernture in ~he range frG~
about 180~C to about 400C ~ut lo~er gha~ ~he ~mpe~ature in 20~ step A to form a product co~aining c~lsro 2,2,~-trifluoroethane, 1,1,1,2-tetrafluoro8~hane, hydro~en chlor~de and unreacted tr~chloroethylene a~d h~drogen fluoride, (C~ treatinB product of ~tep B to separate hydrogen ~ chloride and 1,1,1,2-tetrafluoroethane from : : 25 : l-ch}oro-2,2,2-trifluoroethane, u~reacted hydro~en fluoride a~d u~r~act~d trlchloroethylene; and :~ ~D) fe~di~g l-chloro-2,2,2-trifluoroethane obt~ned from ~t~p C together ~ith hydrogen fluorlde to sald first : ~:
- 30 reaction ~one ~tep (A), ~herein 4 chromium free fluorinati9n c~t~ly8t 8B pre~lously descrlb~d herein i8 employed ln at le88t o~ of ~eps (A~
~ d ( B ) .
;: ~t leagt ~he ~to~chiometric amou~t of h~drogen fluoride i8 usu~lly emplo~ed in 8tep A of the preferr~d embodimen~.

W093tl679X - 10 - PCr/GB93~024~
X~ 3~`~
Typical amount~ include from 1 t~ 10 mDles, a~d preferably from 1 to 6 moles, of hydrogen fluoride per mole of l-chloro-2,2,2-trifluoroethane. ~ccordlngly, the produet of thi~ reactlon step will u~ually co~tain unreacted hydrogen fluoride in additio~ to 1,1.1,2- ~etr~fluoroetha~e, hydrogen chlor~de ~nd b~-product~. Preferred renction ~emperatures for this 3~ge of the prooes~ are ~ the r~nge from 325C to 385C with con~act time~ of from 1 to 100 ~nd preferably from S to 30 seconds ~t 5 to 20 bars pressure.
rom 10 to 100, preferabl~ from lS to 60, mole~ o hydroee~ fluorlde per ~ole of trichloroeth~lene are t~picall~ employed ~n S~ep B. Again, the re2ctlon product of thi~ ~tage will normally cont~in unr~acted hydrogen fluo~ide. Contact ~imes of 1 to 100 second~, prefersbly 5 to 15 30 seoond~ ma~ be u~ed, t~pic~lly at 22~-350C and 5 to 20 b~rs pre~ 8 U re.
It i~ preferred that the process accordl~g to the in~e~on, ~cluding preferred embodiments, ls operated continuously. In praot~:ce, howe~er, cstaly~t deactiYatio~, : 2~ ne~e~siSating periodic ca~alyst regsneration or re~c~ivation ma~ lnterrupt eontinuous operation of the pr~cess. The ~eeding of air to the ca~aly~t during operet~on of the :: ;pr:oce:ss may counter catalyst deactivation and reduce the : frequency of process interruption for catalyBt regeneration or reacti~ation.

: The i~Yention is illu~trated but ~n no Wfly llmited by : the following esamples.

4.79g of alum~a (8upplled by ~arshaw Ltd) in the form of granule~ of size 0.5-1.4mm. and having a surface are~ of 180mZ/g, was added to an aqueous s~lution of 2~C chloride 0.21&) in di~t~lled ~ster (lOml) and ~tirred to ensure tborough wetting o~ the solid by ~he ~olution. The misture , , ~V093/1~79~ PCT/GB9~/~0~4 ~as ~hen drled by direct heatlng and the r~s~ltant soiid sieved to give p~rt~cles of sl~e 0.5-1.4mm of ~ finished ca~alyst comprising about 2.0~ wlw zinc o~ alumi~a. The above pr~cedure was repeated eYcept that z~nc chloride solutions of increasing c~ncentration were employed in order to produce a ra~ge of flnlshed catal~st~ with up to 6.62 wlw zinc in the finlshed catalyst. The fluorination activitie~
of the z~nc promotsd aluminas ~ere measured using an atmo~pheric pressure microreactor. Catalyst~ (2g) were charged to a lJ4~ dlameter microre~ctor a~d ~ere co~ditioned in a 8tr~m of ~F at 300~C for 1 hour and ehen hea~ed ~o 35~C ~nd further conditloned ln an air/~F (ratio 1:20}
Etrea~ for apprs~imatel~ 15hrs.
, The microre c~or was then fed wlth a m~ed 1-chloro-2.2.2-tr~fluoroethane (133a) and ~P feed u~i~g a molar feed ratlD of 1.0:3.5, ~hich gave a 2 seco~d contact t~me at 300~C.
~or purposes of compari60n the unpromoted alumina from which the promoted aluminA6 were prepared wa~ ~150 te~ted.
The results of the stud~ are presented as 2 yields of 1,2 tetrafluoroethane in Table 1 a~d demonstrate the beneficial ~ffect of zinc addition to alumina on increasing the 7ield of 1,1,1,2-tetrafluoroethane (~34B).
The activity of the zinc-impregnated alumina catal~st ~; 25 reached a pesk at a zinc content in t~e range of about 22 to about 3~ w/w.

, 3 ~ TABLE l _ _ . _ _ EXAMPLE CATALYST REACTION TEMPERAT~RE t QC ) . _ l 0.5~Zn-Al203 6.3 4.3 l.96 _ _ 2 . l.O~n-Al203 7.5 5.5 3.27 _ 3 2.0ZZn-Al203 20.l 17.2 ll.3 _ 4 2.22~n-~1203 _ 16.5 ll.o7.4 4.9 1~ 5 3.02Zn-Al~03 l~.7 15.l ll.2 _ 6 4.4~zn-Al2o3 l3.6 9.4 6.6 _ : 7 6.~2Zn-Al203 l9.6 8.l 6.3 _ ~ _ . . .
~: C~p ~1203 O.25 O.lS o.09 _ _ ~ , E~AMPLE B.
4.39g of alumin~ (suppl~ed by ~arshaw Ltd) in the form of granules of ~ize 0.5-l~4mm, and havinB a surface area of ~ 0 180m~1g, wa6 added to ~n BqUeOUS solution of nickel (II~
:~:: chloride hesahydrate (0.41g) and zinc chlor~de (0.2~g) in distilled water (5ml) and stirred to ensure thorough wetting o:f the solid by e~e ~olution. The misture w~s then dried b~
direct heating and ~he re~ultant sol{d 6~eved to g~ve ~ particles, of size 0.5-l.4mm, of ~ f~n~ehed catslygt 8 compri~ing abaut 2.0~ wlw zlnc a~d about 2~ w/w nlckel on ; alumina.
2g of thls catal~se wa~ tested at atmospherlc pres~ure , accordi~g to the procedure of esamples l to 7.
~ ~or purpose~ o~ comparl~on the actlYity of c~ sts : j cqmprising 2~ and 3.8% by weig~t nickel o~ alumina, prepared ~rom a~ a~ueou~ 801ution of nickel (II) chloride 8~
described above were al~o mea~used. The a~omic load~g of the 3.8Z nickel on ~lumina CatRl~St i8 the ~ame 88 that of the catal~t con~a~n~g 2~ zinc and 22 nickel.

:

W093/1679X _ 13 - PCT/GB93/00244 T~e results of the 8tudy are shown as ~ yield~ of 1,1,1,2-tetrafluoroethane in Table 2 and demonstrate the beneficial effect of zlnclnickel addition to alumina compared to alumina ~lone, but nevertheless i~ferior effect of zinc/nickel additlon compared to zinc additlon ~lone ~nd - the even poorer effect of nickel ~dditlon alone.

TAB~E 2 1 0 ' ' ~X~PLE C~TALYST REACTION TE~PERAT~RE(C) _ .
. 340 330 320 310 300 ~: ~ 2~Zn/2~Ni-A1203 ~.4 5.1 3.6 2.7 1.9 , ~
Co~p 2~ 2~3 3.1 2.3 1.61.1 0.7 ::~: ~omp 3.82Ni-A1~03 2-6 ¦1-8 1.30.8 0.5 ~ _ _ _ __ . .

XAMPLE 9, ~: 4.39g of alumina (supplied by ~arshaw Ltd) ~n the form ~of granules of ~ize 0.5-1.4mm, and ha~ing a ~urface ares of 2 180m2/g, wa6 added to an a~ueou~ solut~on of cob~lt ~II) c~loride hexahydrate (0.404g) and zinc chloride (0.21g) ln dl~tllled ~ter (5~1) and st~rred to en~ure thorough w~etlng o~ the sol~d b~ ~he ~olut~on. The mlsture ~a6 then dr~ed b~
direct heating and the r~sultant ~olid 6ie~ed to gi~e particl~6-of ~ize 0.5-1.4mm of a fi~ishe~ cataly~t :: 3~
comprislng 2.0Z w/w zi~c and 2~ w/w cobalt on aluml~a.
!, . ~ ! : ~
: 2g of th~ eatal76t ~a6 te8ted a~ a~mospherlc pres~ure - according to th~ procedure of e~amplea 1 to 7.
or purpose~ of compari~on the act~vity of catalysts co~prising 2~ ~d 3.8~ b~ we~ght cobalt on ~lumi~a, prepared ,~

W~93/1679K _ 14 - PCT/GB93/00244 from An ~queous solution of cobalt (II) chloride a~
de~cribed above, ~ere ~l~o measured. The ~tomic lo~ding of the 3.8~ cobRlt on aluml~a cataly~t i~ the same as that of the ca~al~st co~tsini~g 22 zinc and Z cobalt.
The re~ults of ~he ~tudy are sho~n as ~ ~eld~ of 1,1,1,2 tetrafluoroethane in ~able 3 snd demo~trate ehe be~efi~lal effect of zl~c/cobalt ~ddi ion to ~lumina eompared to alum~a alvne, but ~eYertheless inferior effect vf 2inclcobslt addit$on compared to z~nc addition alone and the eYen poorer ~ffect of cobalt addition alo~e.

15 EX~PLE C~TALYSS ~ACrlON TIYPERAI~IE~C) _ . . . . . ~ ~ ~

~ : 9 2~ZnJ2~Co-A1203 10.9 7.0 5.6 3.6 2.8 : ~ __ . , _ ,, , ,, ¦ Comp ~2Z o~ 03 ~3 9 2.6 ¦l.S ¦1.0 ¦0.5¦

C~ ~ 12O~ ~ ~ ~.S 1.8 1.3 0.9 ; :~;
EXAMPLE 10.
~: 4.43g of alumina (supp1ied by ~ar~haw Ltd) in the form o granules of size 0.5-1.4mm, ~nd h~vi~g a surac2 ~r~a of : ~ l80m2lg. was added to a~ aqueous ~olutlon of ~a~ga~ese (II) chlDride tetrah~drate ~0.36g) a~d zinc c~10ride ~0.21g) ln d~til}ed water (5~1) a~d stirred to ensure thoro~gh ~etting !~ ' o the ~olld b~ the ~olut10~. The mi~ture ~as then dried by direct heati~g snd t~e resu1tant solld ~ieY~d to give : par~icles of ~e 0.$-1.4mm of a fi~l~hed cataly~t : co~prising 2.02 w/w zlnc and 2Z w/w ~ngane6e on a1u~ina.

W093/1679X _ 15 - PCT/GB93/00244 2g of thi~ catsl~st ~as tested at atmospheric pressure accordlng t~ the procedure of e~Rmples 1 to 7.
For purposes of compari~on the acti~ity of catalysts comprising 2~ and 3.68~ by ~eigh~ manganese o~ alumi~a, prepared from B~ aqueous holut~o~ of manganese (II) chloride as described ~bove, were also measured. The atomic loading of ~he 3.68~ ~a~ga~ese on alumina catalyst $8 the ~ame as that of the cataly~t contsining Z~ z~nc ~nd 2Z man8anese.
The re~ults of the study are s~ovn as ~ ~ield8 of 1,1.1,2-tetrafluoroethane ~ Sable 4 a~d demon~trate the benefieial effec~ of z~nclmanganese addition to alumlna co~pared to alu~lna alone, but nevertheles8 inferior effect of zinc ~mangan~se addit~o~ compared to zinc sddition alone snd ~ the eYen poorer effect of mangane~e addition alo~e .

TABLE_4 ~ EXAMPLE CAT~LYST REACTION TE~PERAT~RE(C) : ~ ~ . . _ . _ .
: 3~0 330 3~0 310 1 0 ~ 2 Z n 1 2 2 MD - A 1 2 U 3 1 0 . 5 7 . 7 6 . 7 4 . S

~ ~ : COIIP 2SMn~ 2O3 1 . O O . 7 O . 4 O . 3 :: 2 Comp 3.6BZMn-A1203 0.6 0.5 0.3 0.~ ¦
~ ~ ~ . _ ~: :
EX~MPLES 11 to 20.
: 4.39g of alumi~a (8upplled b~ ~arsh~w Ltd) ~n the form ~: : of gr~nule~ ~f 8ize 0.5-1.4mm, and having a Burface ar~a of 180~2/g, ~a~ added to an ~queous solutlon of iron (III) chlorite (0.07g) s~d zinc chloride (0.63~ d~stllled ter (10~1) a~d ~tlrred to en~ur~ thorough we~ti~g of the solld by the solutlon. The misture wns then tried b~ direct beuti~g und the re~ultant ~olid sievod to give purticle~, of .

W093/1679X - 16 - PCTJGB93/~02~
~8~
size 0.5-1.4mm, of a fi~ished catalyBt comprising 6.0~ wlw inc and 0.5Z ~/~ iron on ~lumina. The above procedure ~a~
repeated e~cept that iron (III) chlorlde and zinc chlorlde ~olutiDns of differe~t concentratlon~ were used to give a range of finished catalysts havin~ the zinc and iron loading~ shown i~ Tnble 5.
2g of esch ~f these c~t~lysts ~ere te~ted at stmospheric pres~ure according to the procedure of esa~p-}es 1 ~o 7.
For purpose6 of comp~ri~on the activity of a caealyst comprising 2~ b~ w~ght lron on alumina, prepared from an aqueous solut~on of iron (III) chloride a8 described ~boveg ~B~ al~o measured. The atomic loading of the 6Z ~/~ zinc and 0.5Z'w/w lro~ on alumina ls equal to that of the 6.6~ w/w zinc on alumlna catal~st (e~ample 7~ and the acti~it~ of the catalyst of e~ample 7 and e~ampl2s 3, 5 and 6 are also ~hown b210w for the purposes of compariso~.
The resul~s of the ~tud~ are ~hown a~ Z ~ields of 1,1,1,2-tetrafluoro2thane in Table 5 and de~onstrste the benefioial ~ffect of zincliron addit~on to alumina co~pared to the addition of iron alone or zinc nlone at rela~vel~
hig~h loading~ of z~c and zinc to iron ratio~ of greater than 2:1.

I

WO ~3/ 1 fi79i~ - 1 7 g~cr/g~g~93/gol)244 2~ 3~

__ ~
EX~MPLE CATALYST ~EACTION TEMPERATURE ( C ) _ _ 3soO 3~0 340330 320 _ _ _ _ 11 2~2n t 12Pe-A1203 13 . 2 11. sO 8 . 9 _ 12 22gZn~2g~e-~1203 13 .9 10 .5 8 .5 _ 13 3SZn/l~e-~120319.3 16.3 10.9 _ 14 3~Zn/2Z~e-A1203 16.D 12.8 9.77.6 15 3ZZ~l 3~e-A1203 10 . 9 9 . 4 6 . 9 _ 16 32Znl 5Z~e-A1203 9 . 8 8 . 9 6 . 9 _ ;~
17 4 2 Z n / l ;~ ~ e - A12 0 313 . 4 12 . 4 9 . 9 _ lR 4~Zn/2g~Fe-A1 03 12 . ? 8 . 9 7 . 7 5 . 9 .
19 6 g~ Z rl / O . 5 ~ e - A 12 0 3 13 . 4 13 . 7 9 . 9 6 . S 4 . 5 6~Zn/1.5g~e-A1203 î3.4 9.4 8.5 5.4 ~: 25 ~-- _~ .
C omp: 2 2 ~ ge -Al 2 0 3 1 . 0 O . o _ _ :~ ~; 3 22Zn-A1203 20 .1 17 . ~ 11. 3 _ _ : .
3 2 Z~l -A ~ 2 0 3 18 . 7 15 . 1 11 . 2 6 14 . 4~Zn-~1203 13 . 6 ~ . 4 6 . 6 _ ~ 10 . 6 8 . 1 6 . 3 _ WO 93/1679X - 18 - P~/GB93/01)244 ;~ ~Lf~
EX~MPLES 21 t~ 25.

The follo~ing esamples ~llustrate that of the metal ~pecies ~ested i~ co~junction ~lth zinc onl~ iro~ gives a more ~cti~e c~t~ t than the 6.6~ b~ Y~-ght ~lnc on alumi~a c~tal~st.
The catalyst~ were prepared according to the method de~cribed previously for esamples 1 to 12 escepe thst the solution~ to ~hich ~he alumina ~s added ~ere as follow~:

E~ample 21 3~me a~ e~ple 12.

E~ample 22 4.07g of alumi~a added to an ~queous 801~tion of ~: 0.63g of Z~C12 a~d 0.3g of CoC12 he~ahydrate i~ 10-ml of water.

E~mple 23 4.07g of alumina added to a~ aqueous solution of ~ 0.63g of ZnC12 a~d 0.3g of NiC12 he~h~drate ~n 10 ~1 of :: ~ater.
:: : .
:~ 2~
: E~ample 24 4.D4g of alumina added to an ~queous æolution of 0.63g of ZnC12 and 0.34g of ~n(c~3co2)2 tetr~h~drate in lOml :~
of water.

E~smpIe 25 4.17g of alumina added to B~ aqueous ~olu~ion of 0.63g of ZnC12 and ~.2g of CuC12 dih7drate i~ 10 ml of wa:t~r.

2g o~ sach o~ these cataly~ts were tes~ed a~
a~ospheric pre~6ure according to the procedure of e~a~ple~
G 7.
; ~ The resul~ D$ the 6tudy are ~ho~n as ~ ~ields of 1,1,1,2-tetra~luor~ethane in T~ble 6 and demonstra~e the : ~ beneficial effec~ of zincliron addltion to alumina compared ~ 35 to ~he addition of any other metal and z~nc to alu~lna.

.

WO 93/ l 679~3 PC~/GB93/00244 Z~ 3~`

EXAMPLE CATALYST ~E~CTION TEMPERATURE ( DC ) . 3 5 o 3 ~ D 3 3 0 3 2 0 21 6~ Zn l l . 52~e-~1203 13 . 4 9 . 4 B . 5 5 . 4 22 15~ZD.I 1. 5%Co-A1203 5 . 5 4 . 7 3 . 2 2 . 8 23 5~Zn~1.5~Ni-~12û3 5.1 3.4 2.8 1.7 2 4 6 ~ Z n / 1 . 5 2 Mn - Al 2 0 3 4 . 7 3 . 7 2 . 5 ~S 6XZnl 1. S~Cu ~12û3 3 . 5 3 . O 2 . 3 ~ 1~ .. , ._ ~ . ,, .-COMP: I 6.62Zn-A1203 8.1 6.3 ~ ~ . --EXAMPLES ~6 ~nd ~7.
4 . 98g, of alusni~ium fluoride, prepared b~ t}~e rehction o:f alumina ( supplied by l~arshaw Ltd ) ~ith hydrogen fluoride at 340C for 48 hours, in the form of ~ .
graslules of size 0 . 5-1. 4mm snd having a sur~ace area of 13m2lg ~as added to an ~queous solution of zinc ~II) chloride (0.D2g) in di~tilled water (5ml) and stirred to eslsure thorough w~tting of the solid b~ the 801ution. The i:sture wa~ th~ dried b~r direct heatlng a~d the resultant solid sieYed to give partlcles of ~e 0.5-1.4mm of a f~ hed cRtal~r~t comp~ising û.22 ~/w zinc oa alumi~lum fluor~de . Th~ ~bo~e procedure ~ra~ repeated e:æcept ehat a zinc (II) chloride ~olutlon of increa~ed concentr~tion was u~ed to give a f inished ca~ ly~t of O . 5~ w/w ZiE~C on aluminiu~ fluorlde.

W093/1~79g - 20 - PCT/GB~3/0024~

3 ~
2g of esch of these catalysts were tested at atmospheric pressure ~ccording t~ the procedure of e~mples l t~ 7.
Por purposes of comparison the ~ctivlty of the unpromo~ed alumlnlum fluoride from ~hich the promoted aluminium fluorlde catalysts were prepared ~as also ~ested.
The results of the study are shown as ~ ~ields of l,l,l,2-tetrafluoroetha~e ln Table 7.

:~ ~

EXAMPLECATALYST ~EACTI0~ TEMPERATURE(C) ~` : ~ 340 330 320 ~ ' 15 _ ,, . . _ ~
260.2~Zn~ 3 l.8 l.3 0.9 27 O.~ZZn-AlF3 l.9 1.2 0.9 ::, . _ _ .

CO~P: L~ ~.1 O.O

EXAMPLE 28 and 29.

~: .
In the6e e~amples, the procedure outlined below wa~
25 : carried out using :the cataly~t prepared in e~ample 7 (exam:ple 28) and eYample 11 ~e~ample 29).

0.67g of the catal~t was ch~rged to ~ l14~ diameter Incone} r~actor tube, dried st 300C and activated by hesti~g ln a stream of h~drogQn fluoride at a flow rate of 20~1/minute for o~e hour. Trichloroethyle~e and hgdrogen luoride weré ~hen fed to the reaotor at atmo~pheric : : pres~ure, u8ing ~ trichloroethylene:hydrogen fluor~de ratio 9f l:~0 and a co~tact time of l ~eoond. T~e ~oti~tg of the cAtal~st w~ ~o~itored at temperatures in the ra~ge between WO93/16798 - 21 - PCT/~B9~/00244 210C and 250C and the results are ~hown as ~Initlal ~CtiYit~ in Table ~.
The temperiature ~aY the~ l~crea~ed to 350C for a 3 da~
period of co~tinuous runnlng. After thls time, the temper~ture ~as lowered to the range 210C ~o 50C and the catal~s~ actlvity mon~tored over ~his temper~ture range. The results re ~hDw~ ~8 ~ctiv~y after 3 da~Y in ~Qble 8. The trlchloroe~hylen2 and hydroge~ fluoride feeds ~ere th~n turned of and the catalyst ~R8 regenerat~d by h~nti~g the ~atalyst at 350C in a s~re~m of air Rt a flow rAte of : lOml/minute for 2 hours. ~fter this tlme, the hydrogen fluoride and trlchl~roethylene flo~s were re-establ~shed at 20ml Iminute and lml /minute respectively a~d the catalyst ; actlvity mon~tored over the temperature range 210C to 250C~ The results are shown as ^Activity after Rege~er~tion~ i~ Table 8. ~11 results of the study a~e pre~e.nted as 2 yields of 1-chloro-2~2~2-trlfluoroethane in Table 8 and demon~itrate the beneficial effect on rege~eration of lron additlon to zi~c promoted catal~ses.

, : ::

WO 93/~679X - ~2 - PCl/GB93/(iO244 T A B L E 8 .

EXAMPLE CATALYST ¦ aEACTION TEMPER.~TIJRE / C

5 j. - __ .
28 6 . 6~ Zn-A1203 ~ Z 3 D ~

I~itial ac~lvlty . 20 .113 . 7 7 . 6 l~ct~ity Rfter 3 hour~.5.1 3.3 1.5 ~c~ ty a~ter regenerat~ on5 ~ 7 3 . 8 2 . O

29 6~ 0 . 52 ~e-A1203 ~: I~tial ~ctivity . 70 . 248 . 2 33 . 4 . Ac~ivLt~r after 3 hours. 32.6 21.1 lS.4 Act ivit~ after rege~eration74 . 3 51. 7 35 . 8 __ ~
. :

.

~: ~` ..

, ::

Claims

CLAIMS.
1. A chromium-free fluorination catalyst comprising an activity promoting amount of zinc and one or more metals other than zinc selected from the group consisting of nickel, cobalt, manganese, iron and copper supported on an alumina, halogenated alumina or aluminium oxyhalide support.
2. A catalyst as claimed in claim 1 wherein the amount of zinc is from about 0.5 % by weight of the catalyst to about 30% by weight of the catalyst.
3. A catalyst as claimed in claim 2 prepared by impregnation of alumina. halogenated alumina or aluminium oxyhalide with a water-soluble zinc salt and comprising from about 0.5% by weight to about 10%
by weight of zinc.
4. A catalyst as claimed in claim 1 prepared by co-precipitating zinc hydroxide and aluminium hydroxide and thereafter converting the hydroxides to the oxides and in which the amount of zinc is from about 3% by weight to about 30% by weight of the catalyst.
5. A catalyst as claimed in claim 1 in which the amount of the metal(s) other than zinc is up to 2.0%
by weight of the catalyst.
6. A catalyst as claimed in claim 1 in which the metal is iron.
7. A catalyst as claimed in claim 1 in which the amount of zinc is at least 3% by weight of the catalyst.
8. A catalyst as claimed in claim 6 in which wt%
ratio of zinc to iron is in the range from about 2:1 to about 80:1 9. A catalyst as claimed in claim 3 comprising zinc in an amount at least 3% by weight of the catalyst and which further comprises from about 0.1% to about 2% by weight iron.

PCT/???3/00244 10. A catalyst as claimed in claim 3 which further comprises iron and in which the ratio (wt% based on the weight of the catalyst) of zinc to iron is from 16:1 to 2:1.
11. A catalyst as claimed in claim 4 which further comprises iron and in which the ratio (wt% based on the weight of the catalyst) of zinc to iron is from about 16:1 to about 2:1.
12. A process for the production of a fluorinated hydrocarbon comprising reacting a hydrocarbon or a halogenated hydrocarbon with hydrogen fluoride in the vapour phase in the presence of a fluorination catalyst as defined in any one of claims 1 to 11.
13. A process as claimed in claim 12 in which the halogenated hydrocarbon comprises an alkene or alkane having from 1 to 4 carbon atoms and at least 1 chlorine atom.
14. A process as claimed in claim 13 in which the halogenated hydrocarbon is selected from the group consisting of 1-chloro-2,2,2-trifluoroethane, trichloroethylene, 1-chloro-2,2-difluoroethylene and perchloroethylene.
15. A process as claimed in claim 14 which comprises the steps (a) reacting trichloroethylene with hydrogen fluoride whereby to produce 1-chloro-2,2,2-trifluoroethane and (b) reacting 1-chloro-2,2,2-trifluoroethane from step (a) with hydrogen fluoride to produce 1,1,1,2-tetrafluoro-ethane, in which a catalyst as claimed in any one of claims 1 to 11 is employed in at least one of steps (a) and (b).
15. A process as claimed in claim 15 which comprises the steps of:
(A) contacting a mixture of 1-chloro-2,2,2-trifluoroethane and hydrogen fluoride PCT/GB?3/00244 with a fluorination catalyst at a temperature in the range from about 280°C to about 450°C in a first reaction zone to form a product containing 1,1,1,2-tetrafluoroethane and hydrogen chloride together with unreacted starting materials, (B) passing product of step A together with trichloroethylene to a second reaction zone containing a fluorination catalyst at a temperature in the range from about 200°C to about 400°C but lower than the temperature in step A to form a product containing 1-chloro-2,2,2-trifluoroethane, 1,1,1,2-tetrafluoroethane, hydrogen chloride and unreacted trichloroethylene and hydrogen fluoride;
(C) treating product of step B to separate hydrogen chloride and 1,1,1,2-tetrafluoroethane from 1-chloro-2,2,2-trifluoroethasne, unreacted hydrogen fluoride and unreacted trichloroethylene, and (D) feeding 1-chloro-2,2,2-trifluoroethane obtained from step C together with hydrogen fluoride to said first reaction zone (step A), in which at least one of the fluorination catalysts employed in step (A) and step (B) is a chromium-free fluorination catalyst as claimed in any one of claims 1 to 11.
17. A process as claimed in any one of claims 12 to 16 in which the catalyst is periodically regenerated by contact with air at a temperature from about 300°C
to about 500°C.