Process for carrying out an equilibrium limited reaction
A reactor having a shell comprising: one or more reactor tubes located within the shell, said reactor tube or tubes comprising a plurality of catalyst receptacles containing catalyst; means for providing a heat transfer fluid to the reactor shell such that the heat transfer fluid contacts the tube or tubes; an inlet for providing reactants to the reactor tubes; and an outlet for recovering products from the reactor tubes; wherein the plurality of catalyst receptacles containing catalyst within a tube comprises catalyst receptacles containing catalyst of at least two configurations.
1. A process for carrying out an equilibrium limited reaction having a Maximum Rate Locus defining temperature at which the equilibrium limited reaction has a maximum reaction rate with respect to a product of the equilibrium reaction as a function of conversion, the process comprising
providing reactants to a reactor having a shell comprising
one or more reactor tubes located within the shell, said reactor tube or tubes comprising a plurality of catalyst receptacles containing catalyst;
means for providing a heat transfer fluid to the reactor shell such that the heat transfer fluid contacts the tube or tubes;
an inlet for providing reactants to the reactor tubes; and
an outlet for recovering products from the reactor tubes;
allowing reaction to occur, and recovering product,
wherein the plurality of catalyst receptacles containing catalyst within a tube comprises catalyst receptacles containing catalyst of at least two configurations such that reaction temperature as a function of conversion in the reactor is within 100° C. of the Maximum Rate Locus.
2. The process according to claim 1 , wherein the process is oxidation of sulphur dioxide to sulphur trioxide, manufacture of ammonia, synthesis of methanol from carbon monoxide and hydrogen, water-gas shift reaction, reverse water-gas shift reaction, manufacture of styrene, dehydration of ethylbenzene, dehydrogenation of alkanes, methanation reactions, or steam methane reforming.
3. The process according to claim 1 , wherein the reaction being carried out is the oxidation of sulphur dioxide to produce sulphur trioxide, and wherein the reaction is operated at an inlet pressure of about 1.4 bara, with initial conversion taking place at about 600° C. to about 700° C. and as conversion progresses, the temperature reduces to about 380° to about 420° C.
4. The process according to claim 1 , wherein the catalyst receptacles containing catalyst differ in type of catalyst within the receptacle, amount of catalyst within the receptacle, amount of heat removed from the receptacle, or combinations thereof.
5. The process according to claim 1 , wherein the catalyst receptacles containing catalyst allow, in use, the temperature of the reaction to be within 100° C. of the equilibrium temperature at a given conversion level.
6. The process according to claim 1 , wherein there are three, four, five, six, seven, eight, nine, or ten different configurations of catalyst receptacles containing catalyst.
7. The process according to claim 1 , wherein the catalyst receptacle comprises:
a container comprising catalyst, said container having a bottom surface closing the container, and a top surface;
a carrier outer wall extending from the bottom surface of said container to the top surface;
a seal extending from the container by a distance which extends beyond the carrier outer wall;
said carrier outer wall having apertures located below the seal.
8. The process according to claim 1 , wherein the catalyst receptacle comprises:
an annular container, said container having a perforated inner container wall defining an inner channel, a perforated outer container wall, a top surface closing the annular container, and a bottom surface closing the annular container;
a surface closing the bottom of said inner channel formed by the inner container wall of the annular container.
9. The process according to claim 1 , wherein the at least two configurations of catalyst receptacles containing catalyst comprises the use of different catalysts.
10. The process according to claim 1 , wherein the at least two configurations of catalyst receptacles comprises a change in the amount of catalyst loaded in the catalyst receptacle.
11. The process according to claim 10 , wherein the change in the amount of catalyst loaded in the catalyst receptacle is achieved by altering the amount of catalyst loaded into the catalyst receptacle and filling the receptacle with inert material.
12. The process according to claim 10 , wherein the change in the amount of catalyst loaded in the catalyst receptacle is achieved by altering the length of the receptacle.
13. The process according to claim 1 , wherein the at least two configurations of catalyst receptacles comprises altering the diameter of the carrier such that when it is loaded into a tube, the annular space between the catalyst receptacle and the reaction tube into which it is to be inserted is altered.
14. The process according to claim 1 using a reactor system comprising the reactor used in combination with one or more conventional adiabatic beds.
15. The process according to claim 14 , wherein the reactor system is configured such that a bulk reaction can be carried out initially in a conventional adiabatic bed before being passed to the reactor.