Reactor for preparing hydrogen cyanide by the andrussow process, equipment comprising said reactor and process using such an equipment

1. Reactor for preparing hydrogen cyanide by the Andrussow process, with at least one gas inlet for reactant gases mixture, a catalyst, at least one support for the catalyst and at least one outlet for the reaction products, wherein said reactor ( 201 ) comprises a cone frustum shaped casing ( 210 ) and comprises inside said casing, a gas distributor ( 202 ) located between a gas inlet (I) and a catalyst ( 203 ), said distributor comprising at least one cone frustum element (Dn) having an upper base directed towards the gas inlet and wherein the gas distributor comprises a plurality of coaxial cone frustum elements (D 1 , . . . , Dn) being arranged around each other with a central cone frustum element having a height h 1 , an outer cone frustum element having an height hn, and intermediate elements having respectively height h 2 , . . . , h(n−1), where h 1 is smaller than h 2 , and respectively h(n−1) is smaller than hn.

2. Reactor for preparing hydrogen cyanide by the Andrussow process according to claim 1 , wherein said reactor ( 201 ) is a cone frustum shaped with cylindrical bases.

3. Reactor for preparing hydrogen cyanide, according to claim 1 , wherein said reactor comprises a safety device ( 215 , P 0 ) to avoid internal overpressure.

4. Reactor for preparing hydrogen cyanide, according to claim 3 , wherein the safety device comprises a rupture disk ( 215 ) and an outer pipe (P 0 ), the rupture disk being located at the end of the outer pipe (P 0 ), said outer pipe being connected above the gas input of the reactor.

5. Reactor for preparing hydrogen cyanide according to claim 1 wherein said reactor further comprises a cooling water jacket ( 209 ) around the casing of the reactor to protect casing of the reactor from catalyst radiance.

6. Reactor for preparing hydrogen cyanide according to claim 1 wherein the reactor comprises, a porous support ( 204 ) for the catalyst ( 203 ) and a porous sub support ( 205 , 206 ) upon which are placed the porous support ( 204 ) and the catalyst ( 203 ), a refractory ring ( 216 ) which is elevating on the border forming the bottom of the reactor and a refractory support ( 207 ) upon which is placed the porous sub-support.

7. Reactor for preparing hydrogen cyanide according to claim 6 wherein the refractory support ( 207 ) is a cone shaped refractory support ( 207 ) comprising a plurality of flow channels ( 208 ) for the reaction products, the base of said cone shaped support being placed under the first porous support of catalyst.

8. Reactor for preparing hydrogen cyanide according to claim 1 wherein, the catalyst comprises catalyst gauzes based on platinum/rhodium gauzes.

9. Reactor for preparing hydrogen cyanide according to claim 1 wherein the porous support ( 204 ) for the catalyst is a foam ceramic produced from Al 2 O 3 more than 99.6% by weight of alumina; or from mullite (Al 2 O 3 +SiO 2 ) with a ratio of 60% to 75% mass of Al 2 O 3 /(Al 2 O 3 +SiO 2 ) and with a high purity of mullite with more than 99.6% mass of mullite.

10. Reactor for preparing hydrogen cyanide according to claim 9 , wherein the porous sub support comprises a first porous sub support and second porous sub support, said first and second sub supports being a ceramic produced from Al 2 O 3 with more than 99.6% by weight of alumina; or from mullite (Al 2 O 3 +SiO 2 ) with a ratio of 60% to 75% mass of Al 2 O 3 /(Al 2 O 3 +SiO 2 ) and a high purity of mullite with more than 99.6% mass of mullite.

11. Reactor for preparing hydrogen cyanide according to claim 6 wherein the porous sub support ( 205 - 206 ) comprises a bed of slotted bricks of Al 2 O 3 .

12. Reactor for preparing hydrogen cyanide according to claim 7 , wherein said refractory cone shaped support ( 207 ) is made of refractory concrete.

13. Reactor for preparing hydrogen cyanide according to claim 1 wherein said reactor comprises a peripheral seal ( 220 ) above the catalyst.