CA1117133A - Orifice plate mixer and method of use - Google Patents
Orifice plate mixer and method of useInfo
- Publication number
- CA1117133A CA1117133A CA000346874A CA346874A CA1117133A CA 1117133 A CA1117133 A CA 1117133A CA 000346874 A CA000346874 A CA 000346874A CA 346874 A CA346874 A CA 346874A CA 1117133 A CA1117133 A CA 1117133A
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- orifice
- fluid
- plate
- mixer
- feedstock
- Prior art date
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Abstract
ABSTRACT
An orifice plate mixer for mixing two fluids has an axial orifice perpendicular to the plate through which bore a first fluid passes and a port in the internal wall of the orifice through which the second fluid passes. The mixer can impart high turbulence to the first fluid and is especially useful in the sulph(on)ation of organic feed-stocks with sulphur trioxide in a recycle loop reactor having said mixer, a pump, a heat exchanger and inlet and outlet for feedstock and reaction products.
An orifice plate mixer for mixing two fluids has an axial orifice perpendicular to the plate through which bore a first fluid passes and a port in the internal wall of the orifice through which the second fluid passes. The mixer can impart high turbulence to the first fluid and is especially useful in the sulph(on)ation of organic feed-stocks with sulphur trioxide in a recycle loop reactor having said mixer, a pump, a heat exchanger and inlet and outlet for feedstock and reaction products.
Description
~17~1l33 oRIFICL~ Pl,AT~ MIX~R AND METIIOD OF_USE
~rhe inventiorl relates to an orifice plate mixer and methods of using it.
This application is a division of our copending Cauadian applica-tion Serial no. 252,555 filed May 14, 1976.
There are many mixing operations in which two or more fluids are to be mixed as quickly as possible to avoid local high concentrations of one of the fluids in contact with the other fluid. Examples of such operations are sulphonation, sulphation or halogenation reactions in which the organic reactant is sensitive -to high concentrations o~ the sulphona-ting/sulphating/haloyenating reagent. Among known mixers are orifice plate mixers, which are described for use in such reac-tions in e.g. British Patent Specification No. 975,914. In this patent specification the sulphonating/sulphating reagent, which l S a sulphur trioxide/air mixture, is caused to flow in an axially directed pipe passing through the axial orifice of the orifice plate mixer with emission of the reagent into the turbulent area downstream of the mixer.
We have now found -that an improved mixing action can be obtained if one of~the fluids is introduced through a port located in the internal wall of the axial orifice of the plate.
Our invention provides a turbulent flow plate mixer for mixing at least two fluids which comprises an orifice which is substantially perpendicular to the plate and a port in the internal wall of the orifice, the orifice being for passage of the first fluid and the port being for passage of the second fluid. The orifice constitutes a bore through the plate with the port a passage in the wall of the bore.
This configuration gives a hiyh degree of turbulence an~ mixing because the fluid passing through an orifice in the plate experiences a relatively high pressure drop and has `- a high Reynolds
~rhe inventiorl relates to an orifice plate mixer and methods of using it.
This application is a division of our copending Cauadian applica-tion Serial no. 252,555 filed May 14, 1976.
There are many mixing operations in which two or more fluids are to be mixed as quickly as possible to avoid local high concentrations of one of the fluids in contact with the other fluid. Examples of such operations are sulphonation, sulphation or halogenation reactions in which the organic reactant is sensitive -to high concentrations o~ the sulphona-ting/sulphating/haloyenating reagent. Among known mixers are orifice plate mixers, which are described for use in such reac-tions in e.g. British Patent Specification No. 975,914. In this patent specification the sulphonating/sulphating reagent, which l S a sulphur trioxide/air mixture, is caused to flow in an axially directed pipe passing through the axial orifice of the orifice plate mixer with emission of the reagent into the turbulent area downstream of the mixer.
We have now found -that an improved mixing action can be obtained if one of~the fluids is introduced through a port located in the internal wall of the axial orifice of the plate.
Our invention provides a turbulent flow plate mixer for mixing at least two fluids which comprises an orifice which is substantially perpendicular to the plate and a port in the internal wall of the orifice, the orifice being for passage of the first fluid and the port being for passage of the second fluid. The orifice constitutes a bore through the plate with the port a passage in the wall of the bore.
This configuration gives a hiyh degree of turbulence an~ mixing because the fluid passing through an orifice in the plate experiences a relatively high pressure drop and has `- a high Reynolds
- 2 -Number at the poin-t of mixing the two fluids; this is true even if the diameter of the oriEice is relatively large;
the length of the orifice is relatively small, being only the thickness of the plate, thus allowing substantial vortex formation and turbulence downstream of the orifice as well as in the orifice.
These characteristics distinguish the turbulent flow plate mixer of the invention from Venturi tubes in which the pressure drop is minimized by providing a convergent entry to and divergent exit from the tube, both of small angle; the velocity is maximized and the turbulence minimized by providing a comparatively small diameter of bore; and the length of the tube ls comparatively large.
The duct leading the second fluid to the port in the wall of the orifice may be drilled through the thickenss of the plate, conveniently in a radial direction.
It is not, however, essential that the port be flush with the internal wall, and it is possible to introduce ; 20 a pipe or collar projecting beyond the wall in a radial, upstream or downstream direction.
The plate may be of circular, square or rectangular cross section with the orifice preferably at its centre, the centre of the port is preferably about equally spaced from the ends of the orifice, e.g. at a distance of 40 -60% of the length of the orifice from the end of the orifice.
Preferably, the mixer comprises an integral plate in which an axial bore or orifice and at least one radial duct or port have been fabricated, e.g. by drilling, the oxifice having the port or ports in its internal wall.
As mentioned above, the configuration of the mixer according 'J~L~3 to th~ lnYerltlon can give a high R~ynold3 number to a fluid pag~ing through the ori1ce. The dimensiona should he such, i~ rela~ion to the ma~ den~ity of the first ~luid, it~ c~sity ~nd line~r velocity in the orifice? that the Reynold~ numb~r in the oriflce i8 greater than the minimum for turbuLent flow, l,e~ 2000~ but prefersbly greater than 30~0~ e.g~ 3000 - 18~0oo~ pre~rably 4l500 ~ 15tO00 a~d especially 10~000 15,000 wh¢n the first fluid i~ a liquld and the ~econd fluid i8 ~oluble there~ or reacts therewi~h, The greal:er the di~meter of the ori~ice for a constant voiume of fluid through the ori~ice the ~malle~ ~he Reynolds number aQd the pres~ure drop across the plate~ 80 .
th~t the choice of diam~ter is a compromise between the deqir¢ for a '', i -hi~h Rey~old~ number giving m~ximum turbulenca ~nd avoldance of a high pro~u~e drop requirlng maximum power i~put. In general the dealgn will b~ a comprdmis~ o~ the conflicting requ~rement~ o~ high throughpu~ and - ~ ~15 Reynold~ number with a reasonable applied pump pre~ure on the one hand and à h~gh pre-~surs dsop across the plate on the other, Tha d~ameter of the oriiic~ in relation to the thichness of tho~plae~ l,e.~the leng h~o tho ~ fico ~9~ elstiYoiy hi~h~
.~ of ;at leas~ O.S ~ I~ e~g.~ 1 to 50~ s 1~ preferably 1 ~ 1 to 20: 1~
; 2~ pecislly l,5 s 1 to~l0 : I. lè :will bo~ undorstood that reference~ to a plato' hcroln include a~fab~icated construc~ion made up of two thin `. plate9 ~oio-d eogeth2r~ the ~space betw~en them being ouch ao to sccommcdate a foed pipe to the~port. The i'oriflce" then tAkas the fonm of a short length of pipe between the two thi~ pla~es.
: 25 I~ de~ired there may Oe:~more ~ban on~ port e.g. 2 - 4 ports in the internal ~all ~f the orifice. The~e ~a~ be used to introduce the same or different fluids.
Preferably the firqt fluid i~ ~n organic f2edstock whlch ~s to be reac~ed wlth the second ~luid in a manner to miuimlse ~Yer-reaction. Thus the secQnd fluid can be a sulphonating, sulphating or halogenating reagent where o~er-reaction can produce discolouration of the product or production of a product having more than the desired n~ber of substitutent groups. This over-reaction can also occur in the reaction of h~droxylic organic feedstocks with an alkylene oxide, e.g. ethylene oxide where it is desired to add only certain number of alkylene oxide units to the feedstock and hence minimize the spread of the number of alkylene oxide units in the product. While the fluids can be liquid or gaseous, the first fluid is preferably liquid, while the second fluid may be liquid or gaseous. The fluids are usually mutually miscible either because o mutual solution or reaction.
The present invention also provides a method of mixing at least two fluids which comprises passing a first fluid through an orifice which is in a plate and substantially perpendicular to the plate, and passing a second fluid into the first fluid through a port in an internal wall of the orifice.
The method of mixing of the invention will be described hereafter with reference to the sulphonating/
sulphating of organic feed stocks with sulphur trioxide in a recycle loop system, but it is equalLy applicable ~
to other reactions in which over-reaction is undesirable whether or not a recycle loop system is adopted, e.g.
in an in line system with mixing of reactants in the mixer and subsequent collection of the reaction products.
In the preferred process the mixing plate used in the present invention forms part of a recycle loop comprising the plate, a pump, a heat exchanger, a line joining these together in a loop, and entry lines into the loop for the feedstock and the sulphur trioxide, L7~3 .
and a take off line Eor -the product. The entry line for the ~eedstock is be~ore the mixer plate in the dlrection of flow in the loop and the entry line for the sulphur trioxide is i~to the mixer. ~hus the second fluid is the sulphur trioxide as gas or liquid and the first fluid is a mixture of organic ~eedstock and its sulph(on)ated product. Preferably the fluids are mixed into the mixer before they reach the pump, i.e. the mixer is on ths inlet side of the pump, and preferably the 1uids pass through the mixer, pump and heat exchanger before the take off line is reached.
When a sulph(on)atable organic compound, e.g.
an aromatic compound such as benzene or a fatty alcohol such as lauryl alcohol is sulph(on)ated by sulphur trioxide, there is a considerable evolution of heat, which, if associated with local high concentrations of sulphur trioxide in the reaction mixture, may give rise to a heavily discoloured reaction product.
In this specification the terms "sulph~on)ated", ~0 "sulph(on)atable" and "sulph(on)ation" means sulphonated, sulphonatable and sulphonation, or sulphated, sulphatable and sulphation, depending on the nature of the compound reacted; thus aromatic hydrocarbons are sulphonated, but fatty alcohols are sulphated. In order to produce light coloured sulph(on)ated products, such as aromatic sulphonic acid reaction products for use, e.g. as surface active~agents or hydrotropes or fatty alcohol sulphate reaction products for use, e.g. as surface active agents, it is usual to moderate the effects of the heat of reaction by diluting the sulphur trioxide, either with an inert gas, e.g. to a 5~ concentration in dry air, or with an L3;~
~nert :L~quid diluent, e.~. a chlorina-ted hydrocarbon or liquid sulphur dioxide. The need for the gaseous or liquid diluent introduces problems o~ purification of the diluent before the reaction and removal thereafter and problems in use. Thus gaseous diluents have to be dried before use and separated from the reaction product afterthe reaction without entra:Lnment of product, unreacted sulph(on)atable compound and/or li.quld diluent. The presence of gaseous diluents in the liquid reaction mediurn means that they are more difficult to pump than liquid phases only. Liquid diluents have to be separated from the reaction product. It has also been proposed to use the sulphur trioxide gas as such and undiluted but under externally applied reduced pressure. It is known to react the sulph(on)atable compound with liquid sulphur trioxide in a complicated apparatus in which the sulphur trioxide is directed at an organic compound present on the surface of at least four moving impeller bIades-which are close to heat transfer surfaces. The reacting mixture of organic compound and sulphur trio~ide is sheared between the impeller blade and the heat transfer surface to reduce the temperature. Finally, it is known to sulph(on)ate sulph(on)atable compounds with a sulphur trioxide/air mixture in a loop reactor with removal of one fifth to one thirtieth of the reaction product and recycle of the rest. It is suggested in a further document that undiluted gaseous sulphur trioxide could be used in a continuous loop process but no details are given.
The mixer of the invention can be used to prepare a sulph(on)ated product by a process with undiluted liquid or gaseous sulphur trioxide in a simple apparatus ~7~3 with a loop in which the organic feedstock is diLuted with its recycled sulph(on~ated reaction product, contact between organic feedstock and sulphur trioxide occurs under conditions of turbulent flow in the mixer and the amount of recycle is very high. The process has the advantage of requiring no diluent for the sulphur trioxide and in the case of alkyl benzene feedstocks often gives light coloured products.
The present invention particularly provides a process for sulph(on)ating a sulph(on)atable organic feedstock, which is preferably an aromatic compound or a fatty alcohol of 8-18 carbon atoms, which comprises passing a reactant liquid comprising the organic feedstock and its sulph(on)ation derivative as the first fluid through a first orifice of a plate, the orifice being substantially perpendicular to the plate, and having a port in the internal wall of the orifice, and passing undiluted sulphur trioxide as second fluid in liquid or gaseous form through said port, preferably the apparent Reynolds number of the reactant liquid in the orifice at the point of meetlng the port being in the range 2000-20,000, e.g. to 18,000, the liquid being in a condition~
of turbulent flow at the point of contact of sulphur trioxide and liquid thereafter in the zone of reaction of sulphur trioxide and liquid, the mixing of the sulphur trioxide and feedstock producing a reactio;n mixture, cooling the reaction mixture before and/or after removing a portion of the reac*ion mixture as sulph~on)ated product, the weight ratio of reaction mixture removed to the remainder of reaction mixture being in the range 1:40 to 1:2000, adding further organic feedstock to the remainder of ~i~'7~3 the reactlon mixtur~ to compensate ~or that removed as product and -to reconstitute the reactant liquid and recy~
cling it or contact with more sulphur trioxide.
The compounds which may be sulphonated in the process of the invention, include aromatic compounds of 6-36 carbon atoms free from groups unstable under the reaction conditions, e.g. free amino groups. Examples are benzene and alkyl benzenes having 1~3 alkyl groups~
each of l-15 carbon atoms, such as alkyl benzenes with 1-3 alkyl groups, each of l to 5, especially l to 3 carbon atoms, e.g. toluene and the three isomers of xylene, and monoalkyl benzenes in which the alkyl group contains 8-15 carbon atoms, e.g. dodecyl benzenes, such as benzene with a linear dodecyl or propylene tetramer side chain.
The aromatic compound may have one or two substitutent which are halogen atoms, such as chlorine or bromine (as in chloro toluenes), hydroxyl groups (as in phenol) or carboxylic groups (as in benzoic acid); the aromatic compound may have one nitro or one sulphonic acid substituent.
The total number of substituents in any benzene ring is usually not more than 3. The naphthalene equivalents of the above compounds, e.g. naphthalene itself may also be sulphonated. Other classes of sulphonatable organic feedstocks are olefins, e.g. those of 8-20 carbon atoms, such as dodec-l-ene, hexadec-l-ene and octadec-l-ene, or random unsaturated hexadecene or vinylidene olefins, and fatty acids, e.g. those of 8-20 carbon atoms such as lauric and stearic acids, as well as olefinic acids, e.g. of 3-20 carbon atoms, preferably 4-18 carbon atoms such as maleic, fumaric and oleic acids.
Examples of sulphatable organic feedstocks .~
the length of the orifice is relatively small, being only the thickness of the plate, thus allowing substantial vortex formation and turbulence downstream of the orifice as well as in the orifice.
These characteristics distinguish the turbulent flow plate mixer of the invention from Venturi tubes in which the pressure drop is minimized by providing a convergent entry to and divergent exit from the tube, both of small angle; the velocity is maximized and the turbulence minimized by providing a comparatively small diameter of bore; and the length of the tube ls comparatively large.
The duct leading the second fluid to the port in the wall of the orifice may be drilled through the thickenss of the plate, conveniently in a radial direction.
It is not, however, essential that the port be flush with the internal wall, and it is possible to introduce ; 20 a pipe or collar projecting beyond the wall in a radial, upstream or downstream direction.
The plate may be of circular, square or rectangular cross section with the orifice preferably at its centre, the centre of the port is preferably about equally spaced from the ends of the orifice, e.g. at a distance of 40 -60% of the length of the orifice from the end of the orifice.
Preferably, the mixer comprises an integral plate in which an axial bore or orifice and at least one radial duct or port have been fabricated, e.g. by drilling, the oxifice having the port or ports in its internal wall.
As mentioned above, the configuration of the mixer according 'J~L~3 to th~ lnYerltlon can give a high R~ynold3 number to a fluid pag~ing through the ori1ce. The dimensiona should he such, i~ rela~ion to the ma~ den~ity of the first ~luid, it~ c~sity ~nd line~r velocity in the orifice? that the Reynold~ numb~r in the oriflce i8 greater than the minimum for turbuLent flow, l,e~ 2000~ but prefersbly greater than 30~0~ e.g~ 3000 - 18~0oo~ pre~rably 4l500 ~ 15tO00 a~d especially 10~000 15,000 wh¢n the first fluid i~ a liquld and the ~econd fluid i8 ~oluble there~ or reacts therewi~h, The greal:er the di~meter of the ori~ice for a constant voiume of fluid through the ori~ice the ~malle~ ~he Reynolds number aQd the pres~ure drop across the plate~ 80 .
th~t the choice of diam~ter is a compromise between the deqir¢ for a '', i -hi~h Rey~old~ number giving m~ximum turbulenca ~nd avoldance of a high pro~u~e drop requirlng maximum power i~put. In general the dealgn will b~ a comprdmis~ o~ the conflicting requ~rement~ o~ high throughpu~ and - ~ ~15 Reynold~ number with a reasonable applied pump pre~ure on the one hand and à h~gh pre-~surs dsop across the plate on the other, Tha d~ameter of the oriiic~ in relation to the thichness of tho~plae~ l,e.~the leng h~o tho ~ fico ~9~ elstiYoiy hi~h~
.~ of ;at leas~ O.S ~ I~ e~g.~ 1 to 50~ s 1~ preferably 1 ~ 1 to 20: 1~
; 2~ pecislly l,5 s 1 to~l0 : I. lè :will bo~ undorstood that reference~ to a plato' hcroln include a~fab~icated construc~ion made up of two thin `. plate9 ~oio-d eogeth2r~ the ~space betw~en them being ouch ao to sccommcdate a foed pipe to the~port. The i'oriflce" then tAkas the fonm of a short length of pipe between the two thi~ pla~es.
: 25 I~ de~ired there may Oe:~more ~ban on~ port e.g. 2 - 4 ports in the internal ~all ~f the orifice. The~e ~a~ be used to introduce the same or different fluids.
Preferably the firqt fluid i~ ~n organic f2edstock whlch ~s to be reac~ed wlth the second ~luid in a manner to miuimlse ~Yer-reaction. Thus the secQnd fluid can be a sulphonating, sulphating or halogenating reagent where o~er-reaction can produce discolouration of the product or production of a product having more than the desired n~ber of substitutent groups. This over-reaction can also occur in the reaction of h~droxylic organic feedstocks with an alkylene oxide, e.g. ethylene oxide where it is desired to add only certain number of alkylene oxide units to the feedstock and hence minimize the spread of the number of alkylene oxide units in the product. While the fluids can be liquid or gaseous, the first fluid is preferably liquid, while the second fluid may be liquid or gaseous. The fluids are usually mutually miscible either because o mutual solution or reaction.
The present invention also provides a method of mixing at least two fluids which comprises passing a first fluid through an orifice which is in a plate and substantially perpendicular to the plate, and passing a second fluid into the first fluid through a port in an internal wall of the orifice.
The method of mixing of the invention will be described hereafter with reference to the sulphonating/
sulphating of organic feed stocks with sulphur trioxide in a recycle loop system, but it is equalLy applicable ~
to other reactions in which over-reaction is undesirable whether or not a recycle loop system is adopted, e.g.
in an in line system with mixing of reactants in the mixer and subsequent collection of the reaction products.
In the preferred process the mixing plate used in the present invention forms part of a recycle loop comprising the plate, a pump, a heat exchanger, a line joining these together in a loop, and entry lines into the loop for the feedstock and the sulphur trioxide, L7~3 .
and a take off line Eor -the product. The entry line for the ~eedstock is be~ore the mixer plate in the dlrection of flow in the loop and the entry line for the sulphur trioxide is i~to the mixer. ~hus the second fluid is the sulphur trioxide as gas or liquid and the first fluid is a mixture of organic ~eedstock and its sulph(on)ated product. Preferably the fluids are mixed into the mixer before they reach the pump, i.e. the mixer is on ths inlet side of the pump, and preferably the 1uids pass through the mixer, pump and heat exchanger before the take off line is reached.
When a sulph(on)atable organic compound, e.g.
an aromatic compound such as benzene or a fatty alcohol such as lauryl alcohol is sulph(on)ated by sulphur trioxide, there is a considerable evolution of heat, which, if associated with local high concentrations of sulphur trioxide in the reaction mixture, may give rise to a heavily discoloured reaction product.
In this specification the terms "sulph~on)ated", ~0 "sulph(on)atable" and "sulph(on)ation" means sulphonated, sulphonatable and sulphonation, or sulphated, sulphatable and sulphation, depending on the nature of the compound reacted; thus aromatic hydrocarbons are sulphonated, but fatty alcohols are sulphated. In order to produce light coloured sulph(on)ated products, such as aromatic sulphonic acid reaction products for use, e.g. as surface active~agents or hydrotropes or fatty alcohol sulphate reaction products for use, e.g. as surface active agents, it is usual to moderate the effects of the heat of reaction by diluting the sulphur trioxide, either with an inert gas, e.g. to a 5~ concentration in dry air, or with an L3;~
~nert :L~quid diluent, e.~. a chlorina-ted hydrocarbon or liquid sulphur dioxide. The need for the gaseous or liquid diluent introduces problems o~ purification of the diluent before the reaction and removal thereafter and problems in use. Thus gaseous diluents have to be dried before use and separated from the reaction product afterthe reaction without entra:Lnment of product, unreacted sulph(on)atable compound and/or li.quld diluent. The presence of gaseous diluents in the liquid reaction mediurn means that they are more difficult to pump than liquid phases only. Liquid diluents have to be separated from the reaction product. It has also been proposed to use the sulphur trioxide gas as such and undiluted but under externally applied reduced pressure. It is known to react the sulph(on)atable compound with liquid sulphur trioxide in a complicated apparatus in which the sulphur trioxide is directed at an organic compound present on the surface of at least four moving impeller bIades-which are close to heat transfer surfaces. The reacting mixture of organic compound and sulphur trio~ide is sheared between the impeller blade and the heat transfer surface to reduce the temperature. Finally, it is known to sulph(on)ate sulph(on)atable compounds with a sulphur trioxide/air mixture in a loop reactor with removal of one fifth to one thirtieth of the reaction product and recycle of the rest. It is suggested in a further document that undiluted gaseous sulphur trioxide could be used in a continuous loop process but no details are given.
The mixer of the invention can be used to prepare a sulph(on)ated product by a process with undiluted liquid or gaseous sulphur trioxide in a simple apparatus ~7~3 with a loop in which the organic feedstock is diLuted with its recycled sulph(on~ated reaction product, contact between organic feedstock and sulphur trioxide occurs under conditions of turbulent flow in the mixer and the amount of recycle is very high. The process has the advantage of requiring no diluent for the sulphur trioxide and in the case of alkyl benzene feedstocks often gives light coloured products.
The present invention particularly provides a process for sulph(on)ating a sulph(on)atable organic feedstock, which is preferably an aromatic compound or a fatty alcohol of 8-18 carbon atoms, which comprises passing a reactant liquid comprising the organic feedstock and its sulph(on)ation derivative as the first fluid through a first orifice of a plate, the orifice being substantially perpendicular to the plate, and having a port in the internal wall of the orifice, and passing undiluted sulphur trioxide as second fluid in liquid or gaseous form through said port, preferably the apparent Reynolds number of the reactant liquid in the orifice at the point of meetlng the port being in the range 2000-20,000, e.g. to 18,000, the liquid being in a condition~
of turbulent flow at the point of contact of sulphur trioxide and liquid thereafter in the zone of reaction of sulphur trioxide and liquid, the mixing of the sulphur trioxide and feedstock producing a reactio;n mixture, cooling the reaction mixture before and/or after removing a portion of the reac*ion mixture as sulph~on)ated product, the weight ratio of reaction mixture removed to the remainder of reaction mixture being in the range 1:40 to 1:2000, adding further organic feedstock to the remainder of ~i~'7~3 the reactlon mixtur~ to compensate ~or that removed as product and -to reconstitute the reactant liquid and recy~
cling it or contact with more sulphur trioxide.
The compounds which may be sulphonated in the process of the invention, include aromatic compounds of 6-36 carbon atoms free from groups unstable under the reaction conditions, e.g. free amino groups. Examples are benzene and alkyl benzenes having 1~3 alkyl groups~
each of l-15 carbon atoms, such as alkyl benzenes with 1-3 alkyl groups, each of l to 5, especially l to 3 carbon atoms, e.g. toluene and the three isomers of xylene, and monoalkyl benzenes in which the alkyl group contains 8-15 carbon atoms, e.g. dodecyl benzenes, such as benzene with a linear dodecyl or propylene tetramer side chain.
The aromatic compound may have one or two substitutent which are halogen atoms, such as chlorine or bromine (as in chloro toluenes), hydroxyl groups (as in phenol) or carboxylic groups (as in benzoic acid); the aromatic compound may have one nitro or one sulphonic acid substituent.
The total number of substituents in any benzene ring is usually not more than 3. The naphthalene equivalents of the above compounds, e.g. naphthalene itself may also be sulphonated. Other classes of sulphonatable organic feedstocks are olefins, e.g. those of 8-20 carbon atoms, such as dodec-l-ene, hexadec-l-ene and octadec-l-ene, or random unsaturated hexadecene or vinylidene olefins, and fatty acids, e.g. those of 8-20 carbon atoms such as lauric and stearic acids, as well as olefinic acids, e.g. of 3-20 carbon atoms, preferably 4-18 carbon atoms such as maleic, fumaric and oleic acids.
Examples of sulphatable organic feedstocks .~
3 ;3 are alcohols, pre~erably fatty ones o~ 8-20 carbon a~oms, such as lauryl, cetyl and stearyl alcohols and mixtures thereof, including mixtures such as are commercially available with a larger proportion of one of these alcohols and smaller amounts of other alcohols. The reaction products of these fatty alcohols with ethylene oxide or propylene oxide which usually contain 1-10 of structural units derived from the oxide may be sulphated. Alkyl phenols with, e.g. 1-12 carbon atoms in the alkyl group, and the reaction products of 1 mole o~ them with, e.g. 1-lO moles of ethylene oxide or propylene oxide, fatty acid alkanol amides, e.g. with 8-18 carbon atoms in the fatty acid part, e.g. that derived from lauric acid and 2-12 carbon atoms in the alkanolamide part, e.g. that derived from mono or di or tri ethanolamine, and the reaction products of l mole of the fatty acid alkanolamides with e.g. 1-10 moles of ethylene oxide or propylene oxide may also be sulphated.
Preferably however, the sulph(on)atable compound is benzene or an alkyl benzene as defined above or a fatty alcohol. The sulphur trioxide is preferably in gaseous form.
The sulph(on)ated products may be used in detergent compositions.
The sulphur trioxide and organic feedstock are contacted in the mixer when the liquid containing the feedstock is in a condition of turbulent flow, preferably with an apparent Reynolds Number of at least 2,000, e.g.
at least 3000, usually 3000 - 18~000, preferably 4500 - 15,000 and especially lO,000 to 15,000. The Reynolds Number can be greater than 18,000 but the higher values become progressively uneconomic. The apparent Reynolds Number is calculated on the assumption that there is no gas phase present, i.e. in the case of the use of gaseous S03 its volume is neglected.
The tubulent flow is achieved by use of the mixer and also in the loop circuit through which the liquid flows there is a pump; the requirement for tubulent flow necessitates a pump operating at a high pumping rate. The turbulent flow occurs in the mixer and in the reaction zone wherever unreacted sulphur trioxide contacts feedstock (or suLph(on)ated derivatives thereof) and reacts with it. Most pumps and heat exchangers ~or cooling the reaction mixture keep turbulent a liquid fed thereinto in a state of turbulent flow.
Fixed pressure pumps, e.g. centrifugal,pumps are preferred though any other type of pump capable of a high pumping rate may be used.
Light colour sulphonates from alkyl benzenes can best be produced if the liquid mixes with the sulphur ~rioxide before passing through the pump rather than afterwards, i.e. the mixer is at the inlet side of the~
pump rather than the outlet side. The recycle loop ;~ system also contains a heat exchanger as cooler, and inlet for ~eedstocks and outlet for reaction mixture.
Preferably the cooler is between the mixer and outlet in the direction of liquid flow. Thus preferably the sulph(on)ation occurs in a recycle loop reactor through which is pumped the reaction liquid and mixture, the reactor having in the direction of flow of the reaction ' .:
1'7~3 mixture and liquid, an inlet ~or ~eedstock, the mixer giving turbulent flow into which sulphur trioxide, preferably in gaseous form is passed, a pump, a heat exchanger as cooler and an outlet for reaction mixture.
The reaction liquid and mixture are preferably in a sta-te of turbulent flow in the mixer, pump and heat exchanger and may be throughout the loop. The sulphur trioxide and feedstock are passed into the loop continuously and the sulph(on)ation product i5 removed continuously.
The temperature of the liquid as it enters the mixer before reaction with sulphur trioxide is primarily governed by the need to control the viscosity of the li~uid, the lower limit being that to maintain a viscosity such that there is turbulent flow, the upper limit being preferably 150C, and pressure being placed on the system if necessary to stop volatili~ation of the organic compound at the liquid temperature. Preferably the temperature of the liquid is 0 - 80~C, and especially 20 - 60C. The use of high temperatures may tend to ~ive greater discolouration in the sulphonated products than occurs at lower temperatures, but the viscosity of the reaction liquid is lower at high temperatures, ~aking for higher turbulence for the sama power input to the pump or the same turbulence with a lower power input. A balance is drawn between the opposing factors.
During the reaction, heat is évolved and the maximum temperature of the effluent reaction mixture is preferably 150C; the usual temperature is 25 - 65 C.
Generally, there is no externally applied vacuum on the loop system in which the reaction mixture and reaction liquid are kept. The loop system is usually ,4 11 ~ ~1 ~.li.~ ' L-.J~
maintained with an external pressure of at least substantially atmospheric, e.g. up to 10 atmospheres and preferably about atmospheric pressure, i.e. there is preferably no externally applied pressure or ~acuum.
The liquid which is reacted with the sulphur trioxide may contain an inert liquid diluent, such as a chlorinated aliphatic hydro-carbon, e.g. carbon tetrachloride. Such a diluent may be desirable when the reaction product is so high melting or of such viscosity that the temperature needed to recycle the reaction product when liquid and give turbulent flow in the mixer would be high enough to result inundue discolouration and/or formation of other byproducts.
Examples of such reaction products are those from naphthalene compounds, alkanolamides, alkoxylated derivatives thereof and aIkoxylated alcohols and phenols.
However, preferably the inert diluent is absent so that no step of separating the diluent after the reaction is needed and the final produat is substantially the sulph(on)ated products or the main liquid contaminent is unreacted feedstock which can be separated and recycled for reuse.
After ~he reaction has occurred, the reaction mixture is cooled, usually to a temperatura the same as the input temperature of the recycle liquid before reaction. The reaction is exothermic the heat of reaction being absorbed in the bulk of the circulating liquid as a heat sink. The cooling is preferably such ~s ~to qive a maximum teIilperature difference of the liquid in different parts of the loop of 50~C especially a .
.
~L~.1'7~3~
maximum difference o~ 10C. The cool:ing may take place in one or more stages with the reaction mixture being passed through one or more heat exchangers.
Usually the portion of reaction mixture is withdrawn as reaction product after at least partial cooling o~ t~e reaction liquid and the remainder is mixed with fresh organic feedstock t:o compensate for the organic feedstock reacted and removed, and to bring the content of feedstock in the mixture back to the value desired for the input feed into the reaction with sulphur trioxide. The liquid with the content of organic sulph(on)atable compound restored in this ~ashion is then recycled for further reaction with sulphur trioxide. Alternatively but less preferred, the reaction mixture may be cooled after the portion is withdrawn, the cooling occurring before or after the fresh feedstock is added.
The portion of reaction mixture taken out of the system constitutes a fourtieth to a two thousandth o~ the weight of the remainder of the reaction mixture recycled, i.e. a recycle ratio of 40 : 1 to 2,000 : 1, preferably 100 : 1 to 1,000 : 1, e.g. 100 : 1 to 700 : 1 and especially 150 - 650 : 1, e.g. 150 - 275 : 1 or 275 - 350 : 1.
The amount of the feedstock in the reaction liquid depends on the nature of the feedstock, the desired composition of the product removed from the system, and the recycle ratio When the feedstock is degraded by a substantial excess of sulphur trioxide and when any unreacted ~eedstock is difficult to separate from the sulph(on)ated ~7~L33 product, as i~ true for most aLiphatic feedstocks and also for example, with dodecyl benzene, the molar ratio of SO3 to feedstock is usually 0.9 : 1 to 1.1 ; 1, e.g. 0.9 : l to 1.05 : 1, preferably 0.93 : 1 to 1.05 : l, especially 0.93 : l to 1.0 : 1. In these cases the molar ratio of the amount of feedstock in the reaction liyuid ta be contacted with SO3 to the amount of sulph(on)ated derivative in that liquid is preferably 0.01 : 99.99 to 5 : 95 and especially about 0.1 : 99.9 to 3 : 9. When the feedstock to be sulphonated is not easily degraded by an excess of SO3, the molar ratio of SO3 to feedstock may be greater than 1 : 1, e.g.
in the range 0.9 : l to 2 : 1 or if unreacted feedstock is more easily separated from the reaction product, as with lower alkyl benaenes then the molar ratio of SO3 to feedstock may be 0.1 : l to l : l e.g. 0.5 : l to 0.95 : l. Molar ratios of SO3 to feedstock greater than 1.2 : l are used when disulphonation, e.g. of aromatic hydrocarbons is desired. The composition of the liquid to be reacted with SO3 can vary over a wide range. When the unreacted feedstock level in the product removed from the system is to be kept low so that the reaction mixture is substantially free (i.e. less than 2%) of unreacted feedstock, ~he molar ratio of feedstock to sulphonated derivative may be 0.01 : 99.99 to lO : 90, preferably 0.01 : 99.99 to 5 : 95, e.g.
0.1 : 99.9 to 3 : 97. When the product is to contain a substantial amount of unreacted volatile feedstock the molar ratio of feedstock to sulphonated derivative may be 5 : 95 to 90 : lO, e.g. 15 : 85 to 90 : lOo i~, ~.17~ 3 The latter proportlons may often be advantageous if the product is to be purified for removal of sulphones obtained with aromatic hydrocarbon feedstocks, because the crude product can be treated with water and the aqueOus sulphonic acid layer separated from an organic layer comprising unreacted feeds~ock and water insoluble impurities, such as the sulphones. The sulphur trioxide : feedstock molar ratio is determined by the desired composition of the product, as well as the nature of the feedstock.
The product removed from the system can be used as such or converted to the corresponding salt by treatment with a base and/or puriied to remove impurities.
Thus in the case of reaction of the aromatic compounds with s~lphur trioxide in a molar ratio of less than 1 : 1.2 the liquid removed from the system comprises any unreacted aromatic compound and sulphonated ompounds which are primarily the mono sulphonic acids of the aromatic~compounds and inert liquid diluent (if used in the reaction) and also may contain small a~ounts of disulphonic acids, sulphuric acid and/or sulphones.
When the molar ratio of sulphur trioxide to aromatic feedstock is greater than 1.2 : 1 the liquid removed from the system comprises sulphonated compounds which are disulphonic acids and monosulphonic acids and inert liquid diluent (if used in the reaction), and may also contain small amounts of unreacted aromatic compound, sulphuric acid and/or sulphones. The sulphonic acids may be sold as such, or after treatment with a base to ~orm an aqueous phase comprising a solution of a sul-phonate salt. The base may be an a~us solution of an alkali metal 7~
hydroxide, carbonate or bicarbonate, e~. sodium hydroxide or sodium carbonate or ammonia or an organic amine, such as trialkyl amine or dialkyl amine, each with 1 to 4 carbon atoms in each alkyl group, e.g. dimethylamine or an alkylolamine, e.y. ethanolamine. Alternatively the liquid is treated with water, optionally after adding a hydrocarbon solvent e.g. benzene, toluene, xylene or paraffin to cause separation into an aqueous phase containiny the sulphonic acids and an organic phase containing unreac-ted aromatic compound and sulphone (and the hydrocarbon added). There is no need to add further hydrocarbon if the product removed from the system contains a sub-stantial amount of unreacted volatile aromatic compound, as mentioned above or water immiscible liquid diluent.
The aqueous sulphonic acid can be used as such or converted into a salt as described above. The treatment o~ the crude liquid with the aqueous solution of base can also be followed by separation of the organic phase as described above. Traces of residual organic feedstock and hydro-carbons can be removed from the sulphonic acid or salt product by stripping e.g. under vacuum.
In order to minimize the production of sulphones in the sulphonation reaction, when the feedstock is benzene or benzene substituted by at least one alkyl chain of 1-5 carbon atoms, it is preferred to carry out the reaction in the presence of a sulphone inhibitor.
The sulphone inhibitor is usually added with the feedstock if it is soluble therein, but otherwise it is added separately to the reaction liquid usually before the addition of the sulphur trioxide. Amounts of inhibitor of up to 10% (by weight based on the weight .33 of the sulphona-ted product) may be used, e.g. up to 5~, preferably 0.5~5% especially 1-5~. The inhibitors may be oxygenated compou~ds, nitrogenous compounds or metal salts. The class of oxygenated compounds includes those described in our British Patent Specification No. 1,306,226 such as cyclic ethers, e.g. of 4-8 carbon atoms such as dioxan or tetrahydrofuran, dialkyl ethers, e.g. of 1-4 carbon atoms in each alkyl group such as diethyl ether, dialkyl ketones, e.g. of 3-7 carbon atoms such as acetone and methyl ethyl ketone cycloaliphatic ketones such as cyclo-hexanone, carboxylic acids, e.g. of 2-6 carbon atoms such as acetic or propionic acids, esters of these carboxylic acids, e.g. with alkanols of 1 to 6 carbon atoms such as ethyl acetate, and anhydrides of those carboxylic acids such as acetic anhydride; acetic acid and acetic anhydride are preferred. The class of nitrogenous compounds includes those described in our British Patent Specification No. 1,304,51~ and includes mono amines e.g. of formula R3N where each R, which may be the same or different, is hydrogen, alkyl e.g. of 1 to 6 carbon atoms, cycloalkyl, e.g. of 5-7 carbon atoms or aryl (preferably aromatic hydrocarbyl), e.g. of 6- `
12 carbon atoms, such as ammonia, di and tri alkyl amines such as triethyl amine and diisopropylamine, primary aromatic and cycloalkyl amines such as aniline and cyclo hexylamine; diamines and triamines; e.g. alkylene diamines of 2-6 carbon atoms such as ethylene diamine and alkylene triamines of ~-10 carbon atoms such as diethylene triamine:
heterocyclic amines such as pyridine, quinoline and iso-quinoline; carboxylic acid amines e.g. the amide from any primary or secondary amine mentioned above preferably '7~i~3 an~onia or dimethyl amine and a carboxylic acid of 1 to 4 carbon atoms such as carbonic, formic and acetic acids, preferably urea, dimethyl formamide and dimethyl acetamide; amine salts, where the amine part can be based on any of the amines mentioned above, e.g. ammonium, and the acid part is from an inorganic acid such as hydro-chloric, sulphuric or phosphoric acid, or an organic, sulphonic or carboxylic acid such as aromatic hydrocarbyl or alkyl sulphonic acids such as xylene-, toluene-, benzene-, or methane sulphonic acids. The metal salts includes alkali metal salts of organic or inorganic acids, which are the alkali metal salt equivalents of the amlne salts mentioned above.
When the sulphonated aromatic product is wanted in its acid form, the inhibitor is preferably an oxygena-ted compound, e.g. acetic acid or acetic anhydride because the other inhibitors introduce often undesirable compounds into the acid, e.g. ammonium salts. ~hen the sulphonated aromatic product is wanted in its salt form, the presence of ammonium salts or production of ammonia as byproducts from, e.g. urea is of no consequence because the neutral-ization of the free acid product liberates the amine or ammonia, which can be separated from the salt.
The feedstock or the sulphone inhibitor (if the latter is not added with the feedstock) may be mixed with up to 300% (by weight of inhibitor), preferably 20-70% of water. The water appears to act as an auxiliary sulphone inhibitor but may result in a higher percentage of free sulphuric acid in the reaction product, which may be desirable in certain applications. Water added alone is a poor sulphone inhibitor and increases the ~1~1'73l~3 content of Eree sulphuric acid in the reaction product considerably. Examples of useful combinakions of inhibitor and water are water and carboxylic acids~ esters or an-hydrides, e.g. water and acetic acid, acetic anhydride or ethyl acetate.
When the oxganic feedstock sulphated is a fatty alcohol, the reaction mixture remo~ed from the system comprises unreacted alcohol and the desired mono alkyl sulphate (and inert diluent if present) together sometimes with the di alkyl sulphate ester. The mixture is usually treated with an aqueous solution of a base, e.g. one as described above to form an aqueous phase comprising an aqueous solution of a sulphate salt. The amount of base is at least sufficient to neutralize the reaction product. Similar operations may be carried out when the feedstock is any of the other sulphatable compounds.
The sulph(on)ated products of our invention can be treated by any of the known techniques used to produce saleable materials. For example, in the case of the sulphonation of olefins having 8-20 carbon atoms it is necessary to include a process step which results in the hydrolysis of the sultones formed in the reaction.
Another example is that in the case of the sulphonation of dodecyl ben~ene it may be desirable to add small amounts of water to the sulphonic acid product in order to prevent the colour of the sulphonic acid darkening on storage and to prevent pH drift of salts produced from it. This procedure is disclosed in British Patent Specification 804,349. If desired one of the process steps in the treatment of the products of the invention can be bleaching - l9a -`~.
3~
by any suitable means.
In a most preEerred process, the sulph(on)ation is carried out in a recycle loop reactor having in the direction of flow of reaction liquid and mixture, an inlet for feedstock, an orifice plate mixer and inlet for sulphur trioxide together i.n a mixer comprising a plate having an orifice, which is substantially perpendicu lar to said plate and a port in the internal wall of the orifice, the ratio of the cliameter of the orifice to the thickness of the plate being 1:1 to 20:1, a pump, a heat exchanger as cooler and an outlet for said reaction mixture, the sulph(on)ation reaction being carried out with undiluted gaseous sulphur trioxide and a reaction liquid free of inert diluent at a temperature of 20-80C under substantially no externally applied pressure or ~m, the Reynolds Number at the point of mixing being 10,000-15,000, the recycle weight ratio.of the reaction mixture removed to the recycled remainder being 1:150-350, preferably 1:150-275 and, when the feedstock is benzene or an alkyl benzene, the reaction liquid also : contains a sulphone inhibitor in amount of 1-5% by weight of feedstock.
The mixer of the invention can be of simple construction and the conditions for successful operation of mixlng and reaction processes using it on a small scale, e.g. o at least 10 lblhr total weight of sulphur ~:: trioxide and added feedstock can be scaled up easlly for larger scale processes, e.g. at least 200 lb~hr.
The invention may be illustrated with reference to the accompanying drawings, in which Figure 1 represents a flow diagram of a preferred process, Figure 2 a flow - l9b -diagram of an alternative but less preerred process, Figure 3 represents a section through a mlxer plate, and its associated pipework~ the section being taken along the line AA of Figure 4 and Figure 4 represents a section along the line BB through the mixer plate of Figure 3.
In Figures 1 and 2 oE the drawings the loop has an input line 1, a pump 2, a turbulent flow mixer 3, an input line 4 to mixer 3, a heat exchanger 5, and an output line 6.
In the operation of Figure 1 the mixture of unreacted organic feedstock and sulph(on)ated organic feedstock (referred to hereafter as a "heel") is circula-ted round the loop by pump 2. Fresh organic feedstock is passed into the loop from line 1 and the mixture of it and the heeel is rendered turbulent, so that the mixture is turbulent at the point in mixer 3 where sulphur trioxide enters the loop from line 4, the reaction mixture produced is drawn through pump 2 and pumped further round the loop through the heat exchanger 5; a very small portion of the reaction mixture is removed through line 6 and ~ the remainder is recycled for contact with fresh organic ; feedstock from line 1. Alternatively the remainder ; of the small portion of the reaction mixture may be removed before passage through the heat exchanger.
The operation of Figure 2 is similar, except ~ that the pump 2 and mixer 3 ar~ transposed.
; Turning now to Figures 3 and 4, conduit 7 with flange 8 is spaced from corresponding conduit 9 and flange 10 by a mixer plate 11 which has an axial orifice 12 at its centre. The ratio of the diameter -- l9c --~, 7~3 of the axial orifice to the length of the orifice ls particularly 1.63:1. From the middle of ori1ce 12 is disposed a radial secondary port 13, the external end of which has been drilled out for a short distance to receive a feedpipe (not shown~.
In use a first fluicl is passed through conduit 7 and thence through axial orifice 12, where it becomes turbulent and meets the second fluid, which has passed through secondary port 13. The turbulent mixture of first and second 1uids then passes further inko conduit 9. The mixer which is described with respect to Figures 3 and 4 may be used in sulph(on)ation processes, the 10w diagrams or which are shown in Figures l and 2.
The invention is illustrated by the Examples set out in the ~ollowing Tables.
The apparatus was as shown in Figure l. The Table gives the approximate Reynolds number at the point of mixing the S03 and the reaction liquid, the Number quoted being calculated on the assumption that there is no gas phase present. In Examples 1-3, tha mixer was one o the invention as illustrated with re~erence to Figures 3 and 4 with a 0.87:1 ratlo of ~: :
:
- l9d -.
.~ '33 ' di~meter of orifice to plate thiclcness nnd in Ex~my1e 4 ~he r,~1xer wn~
one of the invent1on ~9 illuatr~ted with re~erence to Fi~ures 3 nnd ~J
l~ut modif1ed with a 3.5 : 1 ratio of dlameter of orifice to plnte thickness~
S The recycle ra~o quoted ~ the wei~ht r~tio of the circulation rate to the rate of ~eedin~ the feedstock ~nd S03 into the loop; the rate of input feed i9 the ~me as the rate of off ta1ce~
For Exa~ples l, 2 and 4 : the reaction product tak2n from the loop at outlet 6 wa3 snalysecl ~or total acidity (by titrntion with alkali, and expresséd as % sulphuric scid)~ % ~ree sulphuric ~cid~
sulphone, ~ free hydroc~rbon and ~ dlsulphonic ncids, The colour .
~uoted ~as te~ t1mes the re~ding measured usin~ ~n Eel Cvlorimeter with a * ue ~03 filt~r o~ an aqueous ~olution of the ~e~ction product, : obtained by addin~ water to the re~ction product to gi~e a 65% by 15~ ~: weight~ aqueous golutlon of sulphonic ~cid and separating unreacted hydrocarbon and any precipit~te o~ sulphone.
For Example 3 ~ ~he alcollol sulphated WQS ~ mixture of fatty~loo1lo1s:in~whlch Cl2~ snd C~4 alcohoIs predo~insted~ the ~ mixture~being th~t::sold~under the Trad~ m~"Laurex I~C". ~ne - -. 20~ ~reactio~ producé was-~n yield 8 28% aqueouo--~olutionf~whose oolo was measured QS b The neutrali~ed reactio~product;ws~ a1YO analyzed for total surface acti~e~matter~;~odiu~ su1phate~and~fr~e-~fatty matter (by ether extraction of the neutral~zed product) -:
- ~
~ ..... _. ~
o~ ~ 3 o3 ~1 ~ ~ ~; X (D
.. .. .. ..
~o -- ~ . .. -, _ O ~I ~h _ ~ ~ ~n ~ Ul C~ ~ ~ O
.
q C ~ q ea ~ C~
~a p~o . . ~:: o ~ Dn~
; C~ U CL~
/ ~ ~tb ~ ~ ~ g ~ ~ e 7 ~ ~r ~ rr ~ ~ ~
t ~ n' ~ ~ ~ Or~
~ = 1 ~o~ .
' .
_ _ _ o g ¦ n ~ J
Iq __ _ .=~
~ ~ u~ ~r ) m ~r~
d~ .__ 0~ 0 ~IL~l _ 0 ~ ~ ~ o~
~ r:
- , ~ ~ _ ~ - 22 -.
Preferably however, the sulph(on)atable compound is benzene or an alkyl benzene as defined above or a fatty alcohol. The sulphur trioxide is preferably in gaseous form.
The sulph(on)ated products may be used in detergent compositions.
The sulphur trioxide and organic feedstock are contacted in the mixer when the liquid containing the feedstock is in a condition of turbulent flow, preferably with an apparent Reynolds Number of at least 2,000, e.g.
at least 3000, usually 3000 - 18~000, preferably 4500 - 15,000 and especially lO,000 to 15,000. The Reynolds Number can be greater than 18,000 but the higher values become progressively uneconomic. The apparent Reynolds Number is calculated on the assumption that there is no gas phase present, i.e. in the case of the use of gaseous S03 its volume is neglected.
The tubulent flow is achieved by use of the mixer and also in the loop circuit through which the liquid flows there is a pump; the requirement for tubulent flow necessitates a pump operating at a high pumping rate. The turbulent flow occurs in the mixer and in the reaction zone wherever unreacted sulphur trioxide contacts feedstock (or suLph(on)ated derivatives thereof) and reacts with it. Most pumps and heat exchangers ~or cooling the reaction mixture keep turbulent a liquid fed thereinto in a state of turbulent flow.
Fixed pressure pumps, e.g. centrifugal,pumps are preferred though any other type of pump capable of a high pumping rate may be used.
Light colour sulphonates from alkyl benzenes can best be produced if the liquid mixes with the sulphur ~rioxide before passing through the pump rather than afterwards, i.e. the mixer is at the inlet side of the~
pump rather than the outlet side. The recycle loop ;~ system also contains a heat exchanger as cooler, and inlet for ~eedstocks and outlet for reaction mixture.
Preferably the cooler is between the mixer and outlet in the direction of liquid flow. Thus preferably the sulph(on)ation occurs in a recycle loop reactor through which is pumped the reaction liquid and mixture, the reactor having in the direction of flow of the reaction ' .:
1'7~3 mixture and liquid, an inlet ~or ~eedstock, the mixer giving turbulent flow into which sulphur trioxide, preferably in gaseous form is passed, a pump, a heat exchanger as cooler and an outlet for reaction mixture.
The reaction liquid and mixture are preferably in a sta-te of turbulent flow in the mixer, pump and heat exchanger and may be throughout the loop. The sulphur trioxide and feedstock are passed into the loop continuously and the sulph(on)ation product i5 removed continuously.
The temperature of the liquid as it enters the mixer before reaction with sulphur trioxide is primarily governed by the need to control the viscosity of the li~uid, the lower limit being that to maintain a viscosity such that there is turbulent flow, the upper limit being preferably 150C, and pressure being placed on the system if necessary to stop volatili~ation of the organic compound at the liquid temperature. Preferably the temperature of the liquid is 0 - 80~C, and especially 20 - 60C. The use of high temperatures may tend to ~ive greater discolouration in the sulphonated products than occurs at lower temperatures, but the viscosity of the reaction liquid is lower at high temperatures, ~aking for higher turbulence for the sama power input to the pump or the same turbulence with a lower power input. A balance is drawn between the opposing factors.
During the reaction, heat is évolved and the maximum temperature of the effluent reaction mixture is preferably 150C; the usual temperature is 25 - 65 C.
Generally, there is no externally applied vacuum on the loop system in which the reaction mixture and reaction liquid are kept. The loop system is usually ,4 11 ~ ~1 ~.li.~ ' L-.J~
maintained with an external pressure of at least substantially atmospheric, e.g. up to 10 atmospheres and preferably about atmospheric pressure, i.e. there is preferably no externally applied pressure or ~acuum.
The liquid which is reacted with the sulphur trioxide may contain an inert liquid diluent, such as a chlorinated aliphatic hydro-carbon, e.g. carbon tetrachloride. Such a diluent may be desirable when the reaction product is so high melting or of such viscosity that the temperature needed to recycle the reaction product when liquid and give turbulent flow in the mixer would be high enough to result inundue discolouration and/or formation of other byproducts.
Examples of such reaction products are those from naphthalene compounds, alkanolamides, alkoxylated derivatives thereof and aIkoxylated alcohols and phenols.
However, preferably the inert diluent is absent so that no step of separating the diluent after the reaction is needed and the final produat is substantially the sulph(on)ated products or the main liquid contaminent is unreacted feedstock which can be separated and recycled for reuse.
After ~he reaction has occurred, the reaction mixture is cooled, usually to a temperatura the same as the input temperature of the recycle liquid before reaction. The reaction is exothermic the heat of reaction being absorbed in the bulk of the circulating liquid as a heat sink. The cooling is preferably such ~s ~to qive a maximum teIilperature difference of the liquid in different parts of the loop of 50~C especially a .
.
~L~.1'7~3~
maximum difference o~ 10C. The cool:ing may take place in one or more stages with the reaction mixture being passed through one or more heat exchangers.
Usually the portion of reaction mixture is withdrawn as reaction product after at least partial cooling o~ t~e reaction liquid and the remainder is mixed with fresh organic feedstock t:o compensate for the organic feedstock reacted and removed, and to bring the content of feedstock in the mixture back to the value desired for the input feed into the reaction with sulphur trioxide. The liquid with the content of organic sulph(on)atable compound restored in this ~ashion is then recycled for further reaction with sulphur trioxide. Alternatively but less preferred, the reaction mixture may be cooled after the portion is withdrawn, the cooling occurring before or after the fresh feedstock is added.
The portion of reaction mixture taken out of the system constitutes a fourtieth to a two thousandth o~ the weight of the remainder of the reaction mixture recycled, i.e. a recycle ratio of 40 : 1 to 2,000 : 1, preferably 100 : 1 to 1,000 : 1, e.g. 100 : 1 to 700 : 1 and especially 150 - 650 : 1, e.g. 150 - 275 : 1 or 275 - 350 : 1.
The amount of the feedstock in the reaction liquid depends on the nature of the feedstock, the desired composition of the product removed from the system, and the recycle ratio When the feedstock is degraded by a substantial excess of sulphur trioxide and when any unreacted ~eedstock is difficult to separate from the sulph(on)ated ~7~L33 product, as i~ true for most aLiphatic feedstocks and also for example, with dodecyl benzene, the molar ratio of SO3 to feedstock is usually 0.9 : 1 to 1.1 ; 1, e.g. 0.9 : l to 1.05 : 1, preferably 0.93 : 1 to 1.05 : l, especially 0.93 : l to 1.0 : 1. In these cases the molar ratio of the amount of feedstock in the reaction liyuid ta be contacted with SO3 to the amount of sulph(on)ated derivative in that liquid is preferably 0.01 : 99.99 to 5 : 95 and especially about 0.1 : 99.9 to 3 : 9. When the feedstock to be sulphonated is not easily degraded by an excess of SO3, the molar ratio of SO3 to feedstock may be greater than 1 : 1, e.g.
in the range 0.9 : l to 2 : 1 or if unreacted feedstock is more easily separated from the reaction product, as with lower alkyl benaenes then the molar ratio of SO3 to feedstock may be 0.1 : l to l : l e.g. 0.5 : l to 0.95 : l. Molar ratios of SO3 to feedstock greater than 1.2 : l are used when disulphonation, e.g. of aromatic hydrocarbons is desired. The composition of the liquid to be reacted with SO3 can vary over a wide range. When the unreacted feedstock level in the product removed from the system is to be kept low so that the reaction mixture is substantially free (i.e. less than 2%) of unreacted feedstock, ~he molar ratio of feedstock to sulphonated derivative may be 0.01 : 99.99 to lO : 90, preferably 0.01 : 99.99 to 5 : 95, e.g.
0.1 : 99.9 to 3 : 97. When the product is to contain a substantial amount of unreacted volatile feedstock the molar ratio of feedstock to sulphonated derivative may be 5 : 95 to 90 : lO, e.g. 15 : 85 to 90 : lOo i~, ~.17~ 3 The latter proportlons may often be advantageous if the product is to be purified for removal of sulphones obtained with aromatic hydrocarbon feedstocks, because the crude product can be treated with water and the aqueOus sulphonic acid layer separated from an organic layer comprising unreacted feeds~ock and water insoluble impurities, such as the sulphones. The sulphur trioxide : feedstock molar ratio is determined by the desired composition of the product, as well as the nature of the feedstock.
The product removed from the system can be used as such or converted to the corresponding salt by treatment with a base and/or puriied to remove impurities.
Thus in the case of reaction of the aromatic compounds with s~lphur trioxide in a molar ratio of less than 1 : 1.2 the liquid removed from the system comprises any unreacted aromatic compound and sulphonated ompounds which are primarily the mono sulphonic acids of the aromatic~compounds and inert liquid diluent (if used in the reaction) and also may contain small a~ounts of disulphonic acids, sulphuric acid and/or sulphones.
When the molar ratio of sulphur trioxide to aromatic feedstock is greater than 1.2 : 1 the liquid removed from the system comprises sulphonated compounds which are disulphonic acids and monosulphonic acids and inert liquid diluent (if used in the reaction), and may also contain small amounts of unreacted aromatic compound, sulphuric acid and/or sulphones. The sulphonic acids may be sold as such, or after treatment with a base to ~orm an aqueous phase comprising a solution of a sul-phonate salt. The base may be an a~us solution of an alkali metal 7~
hydroxide, carbonate or bicarbonate, e~. sodium hydroxide or sodium carbonate or ammonia or an organic amine, such as trialkyl amine or dialkyl amine, each with 1 to 4 carbon atoms in each alkyl group, e.g. dimethylamine or an alkylolamine, e.y. ethanolamine. Alternatively the liquid is treated with water, optionally after adding a hydrocarbon solvent e.g. benzene, toluene, xylene or paraffin to cause separation into an aqueous phase containiny the sulphonic acids and an organic phase containing unreac-ted aromatic compound and sulphone (and the hydrocarbon added). There is no need to add further hydrocarbon if the product removed from the system contains a sub-stantial amount of unreacted volatile aromatic compound, as mentioned above or water immiscible liquid diluent.
The aqueous sulphonic acid can be used as such or converted into a salt as described above. The treatment o~ the crude liquid with the aqueous solution of base can also be followed by separation of the organic phase as described above. Traces of residual organic feedstock and hydro-carbons can be removed from the sulphonic acid or salt product by stripping e.g. under vacuum.
In order to minimize the production of sulphones in the sulphonation reaction, when the feedstock is benzene or benzene substituted by at least one alkyl chain of 1-5 carbon atoms, it is preferred to carry out the reaction in the presence of a sulphone inhibitor.
The sulphone inhibitor is usually added with the feedstock if it is soluble therein, but otherwise it is added separately to the reaction liquid usually before the addition of the sulphur trioxide. Amounts of inhibitor of up to 10% (by weight based on the weight .33 of the sulphona-ted product) may be used, e.g. up to 5~, preferably 0.5~5% especially 1-5~. The inhibitors may be oxygenated compou~ds, nitrogenous compounds or metal salts. The class of oxygenated compounds includes those described in our British Patent Specification No. 1,306,226 such as cyclic ethers, e.g. of 4-8 carbon atoms such as dioxan or tetrahydrofuran, dialkyl ethers, e.g. of 1-4 carbon atoms in each alkyl group such as diethyl ether, dialkyl ketones, e.g. of 3-7 carbon atoms such as acetone and methyl ethyl ketone cycloaliphatic ketones such as cyclo-hexanone, carboxylic acids, e.g. of 2-6 carbon atoms such as acetic or propionic acids, esters of these carboxylic acids, e.g. with alkanols of 1 to 6 carbon atoms such as ethyl acetate, and anhydrides of those carboxylic acids such as acetic anhydride; acetic acid and acetic anhydride are preferred. The class of nitrogenous compounds includes those described in our British Patent Specification No. 1,304,51~ and includes mono amines e.g. of formula R3N where each R, which may be the same or different, is hydrogen, alkyl e.g. of 1 to 6 carbon atoms, cycloalkyl, e.g. of 5-7 carbon atoms or aryl (preferably aromatic hydrocarbyl), e.g. of 6- `
12 carbon atoms, such as ammonia, di and tri alkyl amines such as triethyl amine and diisopropylamine, primary aromatic and cycloalkyl amines such as aniline and cyclo hexylamine; diamines and triamines; e.g. alkylene diamines of 2-6 carbon atoms such as ethylene diamine and alkylene triamines of ~-10 carbon atoms such as diethylene triamine:
heterocyclic amines such as pyridine, quinoline and iso-quinoline; carboxylic acid amines e.g. the amide from any primary or secondary amine mentioned above preferably '7~i~3 an~onia or dimethyl amine and a carboxylic acid of 1 to 4 carbon atoms such as carbonic, formic and acetic acids, preferably urea, dimethyl formamide and dimethyl acetamide; amine salts, where the amine part can be based on any of the amines mentioned above, e.g. ammonium, and the acid part is from an inorganic acid such as hydro-chloric, sulphuric or phosphoric acid, or an organic, sulphonic or carboxylic acid such as aromatic hydrocarbyl or alkyl sulphonic acids such as xylene-, toluene-, benzene-, or methane sulphonic acids. The metal salts includes alkali metal salts of organic or inorganic acids, which are the alkali metal salt equivalents of the amlne salts mentioned above.
When the sulphonated aromatic product is wanted in its acid form, the inhibitor is preferably an oxygena-ted compound, e.g. acetic acid or acetic anhydride because the other inhibitors introduce often undesirable compounds into the acid, e.g. ammonium salts. ~hen the sulphonated aromatic product is wanted in its salt form, the presence of ammonium salts or production of ammonia as byproducts from, e.g. urea is of no consequence because the neutral-ization of the free acid product liberates the amine or ammonia, which can be separated from the salt.
The feedstock or the sulphone inhibitor (if the latter is not added with the feedstock) may be mixed with up to 300% (by weight of inhibitor), preferably 20-70% of water. The water appears to act as an auxiliary sulphone inhibitor but may result in a higher percentage of free sulphuric acid in the reaction product, which may be desirable in certain applications. Water added alone is a poor sulphone inhibitor and increases the ~1~1'73l~3 content of Eree sulphuric acid in the reaction product considerably. Examples of useful combinakions of inhibitor and water are water and carboxylic acids~ esters or an-hydrides, e.g. water and acetic acid, acetic anhydride or ethyl acetate.
When the oxganic feedstock sulphated is a fatty alcohol, the reaction mixture remo~ed from the system comprises unreacted alcohol and the desired mono alkyl sulphate (and inert diluent if present) together sometimes with the di alkyl sulphate ester. The mixture is usually treated with an aqueous solution of a base, e.g. one as described above to form an aqueous phase comprising an aqueous solution of a sulphate salt. The amount of base is at least sufficient to neutralize the reaction product. Similar operations may be carried out when the feedstock is any of the other sulphatable compounds.
The sulph(on)ated products of our invention can be treated by any of the known techniques used to produce saleable materials. For example, in the case of the sulphonation of olefins having 8-20 carbon atoms it is necessary to include a process step which results in the hydrolysis of the sultones formed in the reaction.
Another example is that in the case of the sulphonation of dodecyl ben~ene it may be desirable to add small amounts of water to the sulphonic acid product in order to prevent the colour of the sulphonic acid darkening on storage and to prevent pH drift of salts produced from it. This procedure is disclosed in British Patent Specification 804,349. If desired one of the process steps in the treatment of the products of the invention can be bleaching - l9a -`~.
3~
by any suitable means.
In a most preEerred process, the sulph(on)ation is carried out in a recycle loop reactor having in the direction of flow of reaction liquid and mixture, an inlet for feedstock, an orifice plate mixer and inlet for sulphur trioxide together i.n a mixer comprising a plate having an orifice, which is substantially perpendicu lar to said plate and a port in the internal wall of the orifice, the ratio of the cliameter of the orifice to the thickness of the plate being 1:1 to 20:1, a pump, a heat exchanger as cooler and an outlet for said reaction mixture, the sulph(on)ation reaction being carried out with undiluted gaseous sulphur trioxide and a reaction liquid free of inert diluent at a temperature of 20-80C under substantially no externally applied pressure or ~m, the Reynolds Number at the point of mixing being 10,000-15,000, the recycle weight ratio.of the reaction mixture removed to the recycled remainder being 1:150-350, preferably 1:150-275 and, when the feedstock is benzene or an alkyl benzene, the reaction liquid also : contains a sulphone inhibitor in amount of 1-5% by weight of feedstock.
The mixer of the invention can be of simple construction and the conditions for successful operation of mixlng and reaction processes using it on a small scale, e.g. o at least 10 lblhr total weight of sulphur ~:: trioxide and added feedstock can be scaled up easlly for larger scale processes, e.g. at least 200 lb~hr.
The invention may be illustrated with reference to the accompanying drawings, in which Figure 1 represents a flow diagram of a preferred process, Figure 2 a flow - l9b -diagram of an alternative but less preerred process, Figure 3 represents a section through a mlxer plate, and its associated pipework~ the section being taken along the line AA of Figure 4 and Figure 4 represents a section along the line BB through the mixer plate of Figure 3.
In Figures 1 and 2 oE the drawings the loop has an input line 1, a pump 2, a turbulent flow mixer 3, an input line 4 to mixer 3, a heat exchanger 5, and an output line 6.
In the operation of Figure 1 the mixture of unreacted organic feedstock and sulph(on)ated organic feedstock (referred to hereafter as a "heel") is circula-ted round the loop by pump 2. Fresh organic feedstock is passed into the loop from line 1 and the mixture of it and the heeel is rendered turbulent, so that the mixture is turbulent at the point in mixer 3 where sulphur trioxide enters the loop from line 4, the reaction mixture produced is drawn through pump 2 and pumped further round the loop through the heat exchanger 5; a very small portion of the reaction mixture is removed through line 6 and ~ the remainder is recycled for contact with fresh organic ; feedstock from line 1. Alternatively the remainder ; of the small portion of the reaction mixture may be removed before passage through the heat exchanger.
The operation of Figure 2 is similar, except ~ that the pump 2 and mixer 3 ar~ transposed.
; Turning now to Figures 3 and 4, conduit 7 with flange 8 is spaced from corresponding conduit 9 and flange 10 by a mixer plate 11 which has an axial orifice 12 at its centre. The ratio of the diameter -- l9c --~, 7~3 of the axial orifice to the length of the orifice ls particularly 1.63:1. From the middle of ori1ce 12 is disposed a radial secondary port 13, the external end of which has been drilled out for a short distance to receive a feedpipe (not shown~.
In use a first fluicl is passed through conduit 7 and thence through axial orifice 12, where it becomes turbulent and meets the second fluid, which has passed through secondary port 13. The turbulent mixture of first and second 1uids then passes further inko conduit 9. The mixer which is described with respect to Figures 3 and 4 may be used in sulph(on)ation processes, the 10w diagrams or which are shown in Figures l and 2.
The invention is illustrated by the Examples set out in the ~ollowing Tables.
The apparatus was as shown in Figure l. The Table gives the approximate Reynolds number at the point of mixing the S03 and the reaction liquid, the Number quoted being calculated on the assumption that there is no gas phase present. In Examples 1-3, tha mixer was one o the invention as illustrated with re~erence to Figures 3 and 4 with a 0.87:1 ratlo of ~: :
:
- l9d -.
.~ '33 ' di~meter of orifice to plate thiclcness nnd in Ex~my1e 4 ~he r,~1xer wn~
one of the invent1on ~9 illuatr~ted with re~erence to Fi~ures 3 nnd ~J
l~ut modif1ed with a 3.5 : 1 ratio of dlameter of orifice to plnte thickness~
S The recycle ra~o quoted ~ the wei~ht r~tio of the circulation rate to the rate of ~eedin~ the feedstock ~nd S03 into the loop; the rate of input feed i9 the ~me as the rate of off ta1ce~
For Exa~ples l, 2 and 4 : the reaction product tak2n from the loop at outlet 6 wa3 snalysecl ~or total acidity (by titrntion with alkali, and expresséd as % sulphuric scid)~ % ~ree sulphuric ~cid~
sulphone, ~ free hydroc~rbon and ~ dlsulphonic ncids, The colour .
~uoted ~as te~ t1mes the re~ding measured usin~ ~n Eel Cvlorimeter with a * ue ~03 filt~r o~ an aqueous ~olution of the ~e~ction product, : obtained by addin~ water to the re~ction product to gi~e a 65% by 15~ ~: weight~ aqueous golutlon of sulphonic ~cid and separating unreacted hydrocarbon and any precipit~te o~ sulphone.
For Example 3 ~ ~he alcollol sulphated WQS ~ mixture of fatty~loo1lo1s:in~whlch Cl2~ snd C~4 alcohoIs predo~insted~ the ~ mixture~being th~t::sold~under the Trad~ m~"Laurex I~C". ~ne - -. 20~ ~reactio~ producé was-~n yield 8 28% aqueouo--~olutionf~whose oolo was measured QS b The neutrali~ed reactio~product;ws~ a1YO analyzed for total surface acti~e~matter~;~odiu~ su1phate~and~fr~e-~fatty matter (by ether extraction of the neutral~zed product) -:
- ~
~ ..... _. ~
o~ ~ 3 o3 ~1 ~ ~ ~; X (D
.. .. .. ..
~o -- ~ . .. -, _ O ~I ~h _ ~ ~ ~n ~ Ul C~ ~ ~ O
.
q C ~ q ea ~ C~
~a p~o . . ~:: o ~ Dn~
; C~ U CL~
/ ~ ~tb ~ ~ ~ g ~ ~ e 7 ~ ~r ~ rr ~ ~ ~
t ~ n' ~ ~ ~ Or~
~ = 1 ~o~ .
' .
_ _ _ o g ¦ n ~ J
Iq __ _ .=~
~ ~ u~ ~r ) m ~r~
d~ .__ 0~ 0 ~IL~l _ 0 ~ ~ ~ o~
~ r:
- , ~ ~ _ ~ - 22 -.
Claims (32)
1. A method of mixing at least two fluids comprising a first fluid and a second fluid, which method comprises passing said fluids separately into a turbulent flow plate mixer comprising a plate, means defining an orifice through said plate, said orifice being substantially perpendicular to said plate, an internal wall to said orifice, and means defining at least one port in said wall, said first fluid being passed through said orifice and said second fluid being passed into said port.
2. A method according to Claim 1 wherein the ratio of the diameter of said orifice to the thickness of said plate is 0.5 : 1 to 50 : 1 .
3. A method according to Claim 2 wherein the ratio of the diameter of said orifice to the thickness of said plate is 1 : 1 to 10 : 1.
4. A method according to Claim 1 wherein the first fluid is a liquid, the second fluid is soluble in or reacts with the first fluid and the apparent Reynolds number of the first fluid at the point of contact with the second fluid is 10,000 to 15,000.
5. A method according to Claim 1 for sulph(on)ating a sulph(on)atable organic feed stock which comprises passing undiluted sulphur trioxide in liquid or gaseous form as said second fluid though said port into a reactant liquid comprising the organic feedstock and its sulph(on)ation derivative passing as said first fluid through said orifice to give a reaction mixture, the apparent Reynolds Number of the reactant liquid in said orifice at the point of meeting the port being 2000 - 18,000 and the liquid at the point of meeting the port and thereafter in the zone of reaction of the sulphur trioxide and liquid being in a condition of turbulent flow, cooling the reaction mixture before and/or after removing a portion of the reaction mixture as sulph(on)ated product, the weight ratio of reaction mixture removed to the remainder of reaction mixture being in the range 1 : 40 to 1 : 2000, adding further organic feedstock to the remainder of the reaction mixture to compensate for that removed as product and to reconstitute the reaction liquid and recycling it for contact with more sulphur trioxide.
6. A method according to Claim 5 wherein the reactant mixture and reaction liquid are in a loop system maintained under no externally applied vacuum.
7. A method according to Claim 5 wherein the apparent Reynolds Number of the reaction liquid in said orifice is 4,500 - 18,000.
8. A method according to Claim 7 wherein the apparent Reynolds Number of the reaction liquid in said orifice is 10,000 to 15,000.
9. A method according to Claim 5 wherein the weight ratio of the reaction mixture removed to the recycled remainder is 1 : 100 to 1 : 700.
10. A method according to Claim 5 wherein the sulphur trioxide is in gaseous form.
11. A method according to Claim 5 wherein the ratio of the diameter of the orifice to the thickness of the plate is 1 : 1 to 10 : 1.
12. A method according to Claim 5 wherein the reaction liquid and sulphur trioxide are contacted at a temperature of 0 - 80°C.
13. A method according to Claim 5 wherein the reaction liquid is substantially free of any inert liquid diluent,
14. A method according to Claim 5 wherein the molar ratio of sulphur trioxide to feedstock is such that the reaction mixture is substantially free of unreacted feedstock.
15. A method according to Claim 5 which is carried out in a recycle loop reactor having in the direction of flow of the reaction liquid and mixture, an inlet for feedstock, said mixer giving turbulent flow to the reaction liquid a pump, a heat exchanger as cooler and an outlet for reaction mixture.
16. A method according to Claim 5 wherein the feedstock is benzene or an alkyl benzene having 1 - 3 alkyl groups each of 1 to 3 carbon atoms, or a fatty alcohol of 8 - 20 carbon atoms.
17. A process according to Claim 16 wherein the feedstock is toluene or xylene.
18. A process according to Claim 16 in which the feedstock is benzene or an alkyl benzene, wherein the reaction liquid also comprises a sulphone inhibitor in amount of up to 10% by weight based on the weight of the feed-stock.
19. A process according to Claim 18 wherein the inhibitor is acetic acid, acetic anhydride or an alkyl acetate with 1 - 6 carbon atoms in the alkyl group.
20. A process according to Claim 18 wherein water is added to the feed-stock in amounts of up to 300% by weight of the inhibitor.
21. A process according to Claim 18 wherein the inhibitor is an amine or ammonium salt, amide or urea.
22. A method according to Claim 5 wherein the portion of the sulphon-ated reaction mixture withdrawn is treated with water to give an aqueous phase comprising an aqueous solution of a sulphonic acid.
23. A method according to Claim 5 wherein the portion of the sulphonated or sulphated reaction mixture is treated with an aqueous solution of a base to give an aqueous phase comprising a solution of a sulphonate or sulphate salt.
24. A method according to Claim 16 wherein the sulph(on)ation is carried out in a recycle loop reactor having in the direction of flow of reaction liquid and mixture, an inlet for feedstock, said turbulent flow plate mixer, the ratio of the diameter of said orifice to the thickness of said plate being 1 : 1 to 20 : 1, a pump, a heat exchanger as cooler and an outlet for said reaction mixture, the sulph(on)ation reaction being carried out with undiluted gaseous sulphur trioxide and a reaction liquid free of inert diluent at a temperature of 20 - 80°C under substantially no externally applied pressure or vacuum, the Reynolds Number at the point of mixing being 10,000 - 15,000, the weight ratio of the reaction mixture removed to the recycled remainder being 1:150-350 and, when the feedstock is benzene or an alkyl benzene, the reaction liquid also contains a sulphone inhibitor in amount of 1 - 5% by weight of feedstock.
25. A turbulent flow plate mixer for mixing at least two fluids fluids comprising a first fluid and a second fluid, said mixer comprising a plate, means defining an orifice through said plate, said orifice being substantially perpendicular to said plate, an internal wall to said orifice, means defining at least one port in said wall, said orifice being for passage of said first fluid and said port being for passage of said second fluid, and a conduit attached to at least one end of said orifice.
26. A mixer according to Claim 25 wherein the ratio of the diameter of said orifice to the thickness of said plate is 1:1 to 50:1.
27. A mixer according to Claim 26 wherein the ratio of the diameter of said orifice to the thickness of said plate is 1:1 to 10:1.
28. A mixer according to Claim 25 which comprises a plate, in which an axial orifice and at least one radial passage have been drilled, said passage being drilled into the internal wall of the orifice to provide said port.
29. A recycle loop reactor having in the direction of flow, an inlet for a first fluid, a mixer comprising a plate having means defining an orifice, which is substantially perpendicular to said plate, an internal wall to said orifice and means defining at least one port in said wall, a pump, a heat exchanger as cooler and an outlet, the inlet, mixer pump heat exchanger and outlet all being joined together by a line into a loop, and said means defining a port constituting an inlet for a second fluid.
30. A mixer according to claim 25 having an integral structure and including from 1 to 4 radial ports.
31. A mixer according to claim 30 wherein a conduit communicates with both ends of said orifice.
32. A mixer according to claim 30 or 31 wherein said conduit has a larger cross-sectional size than said orifice whereby said orifice acts as a constriction to the first fluid flowing through it.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000346874A CA1117133A (en) | 1975-05-15 | 1980-03-03 | Orifice plate mixer and method of use |
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB20567/75A GB1563994A (en) | 1975-05-15 | 1975-05-15 | Sulph(on)ation process and mixer |
| GB2056875 | 1975-05-15 | ||
| GB20568/75 | 1975-05-15 | ||
| CA252,555A CA1072976A (en) | 1975-05-15 | 1976-05-14 | Sulphonation process and apparatus |
| GB11355/79A GB1563995A (en) | 1975-05-15 | 1976-08-11 | Mixer and mixing process |
| ZA766021A ZA766021B (en) | 1975-05-15 | 1976-10-07 | Sulphonation process and apparatus |
| US05/857,807 US4226796A (en) | 1975-05-15 | 1977-12-05 | Sulph(on)ation process |
| CA000346874A CA1117133A (en) | 1975-05-15 | 1980-03-03 | Orifice plate mixer and method of use |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1117133A true CA1117133A (en) | 1982-01-26 |
Family
ID=27560881
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000346874A Expired CA1117133A (en) | 1975-05-15 | 1980-03-03 | Orifice plate mixer and method of use |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1117133A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8129559B2 (en) | 2006-12-08 | 2012-03-06 | Evonik Röhm Gmbh | Process for preparing cyanohydrins and their use in the preparation of alkyl esters of methacrylic acid |
-
1980
- 1980-03-03 CA CA000346874A patent/CA1117133A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8129559B2 (en) | 2006-12-08 | 2012-03-06 | Evonik Röhm Gmbh | Process for preparing cyanohydrins and their use in the preparation of alkyl esters of methacrylic acid |
| RU2497805C2 (en) * | 2006-12-08 | 2013-11-10 | Эвоник Рем ГмбХ | Method of obtaining acetonecyanohydrin |
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