Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
192 words
A catalytic process for production of sulphur from a gas, known as an "acid gas", containing H 2 S, in which the acid gas is contacted, at a temperature between 200° and 1000° C. and in the presence of a H 2 S-oxidation catalyst, with a controlled quantity of a gas containing free oxygen in order to form a gaseous effluent containing H 2 S and SO 2 in a H 2 S to SO 2 molar ratio substantially equal to 2:1 as well as sulphur, then said effluent, after cooling, is contacted with a CLAUS catalyst in order to form a further quantity of sulphur, wherein the H 2 S-oxidation catalyst consists of agglomerates having a surface area of at least 5 m 2 /g and comprising an active alumina and either: (a) containing silica as a thermal stabilizer in an amount from 0.5 to 20% by weight of the alumina, to which is associated a compound of iron; or (b) containing lanthanum oxide and neodymimium oxide as a thermal stabilizer in an amount from 0.5 to 20% by weight of the alumina, to which is associated a compound of iron.
Claim 2
Dependent Claim
192 words
A catalytic process for production of sulphur from a gas, known as an "acid gas", containing H 2 S, in which the acid gas is contacted, at a temperature between 200° and 1000° C. and in the presence of a H 2 S-oxidation catalyst, with a controlled quantity of a gas containing free oxygen in order to form a gaseous effluent containing H 2 S and SO 2 in a H 2 S to SO 2 molar ratio substantially equal to 2:1 as well as sulphur, then said effluent, after cooling, is contacted with a CLAUS catalyst in order to form a further quantity of sulphur, wherein the H 2 S-oxidation catalyst consists of agglomerates having a surface area of at least 5 m 2 /g and comprising an active alumina and either: (a) containing silica as a thermal stabilizer in an amount from 0.5 to 20% by weight of the alumina, to which is associated a compound of iron; or (b) containing lanthanum oxide and neodymimium oxide as a thermal stabilizer in an amount from 0.5 to 20% by weight of the alumina, to which is associated a compound of iron.
Claim 3
Dependent Claim
31 words
A process according to claim 1, wherein the active alumina is thermally stabilized by a quantity of stabilizing oxide or oxides ranging from 1 to 10% by weight of the alumina.
Claim 4
Dependent Claim
25 words
A process according to claim 1, wherein the agglomerates of thermally stabilized active alumina have a surface area of at least 40 m 2 /g.
Claim 5
Dependent Claim
18 words
A process according to claim 3, wherein said surface area is between 60 and 200 m 2 /g.
Claim 6
Dependent Claim
35 words
A process according to claim 1, wherein the overall quantity of the metal compound(s) associated with the agglomerates of thermally stabilized active alumina ranges from 0.5 to 15% of the weight of the calcinated catalyst.
Claim 7
Dependent Claim
22 words
A process according to claim 5, wherein said overall quantity ranges from 2 to 12% of the weight of the calcinated catalyst.
Claim 8
Dependent Claim
13 words
A process according to claim 1, wherein said iron compound is iron sulphate.
Claim 9
Dependent Claim
19 words
A process according to claim 1, wherein the acid gas contains less than 25% H 2 S by volume.
Claim 10
Dependent Claim
20 words
A process according to claim 8, wherein the acid gas contains from 0.5 to 20% H 2 S by volume.
Claim 11
Dependent Claim
36 words
A process according to claim 1, wherein the acid gas contains less than 25% H 2 S by volume and one or more organic sulphur compounds in an amount of up to about 1% by volume.
Claim 12
Dependent Claim
24 words
A process according to claim 10, wherein said organic sulphur compounds are selected from the group consisting of mercaptans, COS and CS 2 .
Claim 13
Dependent Claim
20 words
A process according to claim 10, wherein the acid gas contains from 0.5 to 20% H 2 S by volume.
Claim 14
Dependent Claim
28 words
A process according to claim 1, wherein the oxidation of H 2 S in the acid gas is achieved at a temperature between 200° C. and 900° C.
Claim 15
Dependent Claim
92 words
A process according to claim 1, wherein the oxidation effluent has a H 2 S content lower than 2% by volume, and the contacting of said effluent with the CLAUS catalyst is achieved at a temperature lower than the dew point of sulphur contained in the effluent, said temperature being between 80° C. and 160° C., and the CLAUS catalyst that is loaded with the sulphur that has been formed is periodically regenerated by sweeping with a gas devoid of free oxygen and at a temperature between 200° C. and 400° C.
Claim 16
Dependent Claim
99 words
A process according to claim 14, wherein said contacting with the CLAUS catalyst is achieved in a series of catalyst converters, that operate in such a way that at least one of said converters is in the regeneration phase whereas the others are in the CLAUS reaction phase, and the effluent from the oxidation zone is caused to pass, first of all, into the or each converter which is in the regeneration phase, in order to ensure sweeping of the sulphur loaded catalyst contained therein, then after separation of the sulphur, into the or each CLAUS reaction phase converter.
Claim 17
Dependent Claim
67 words
A process according to claim 1 wherein the oxidation effluent has a H 2 S content equal to or higher than 2% by volume and the contacting of said effluent with the CLAUS catalyst is carried out at a temperature higher than the dew point of sulphur contained in the effluent through operating in a single catalytic converter or in several of such converters arranged in series.
Claim 18
Dependent Claim
20 words
A process according to claim 16, wherein said contacting is carried out at temperatures between 200° C. and 450° C.
Claim 19
Dependent Claim
50 words
A process according to claim 16, wherein the contacting of the oxidation effluent with the CLAUS catalyst at a temperature higher than the dew point of sulphur contained in the oxidation effluent is followed by a contacting with a CLAUS catalyst at a temperature below said dew point of sulphur.
Claim 20
Dependent Claim
23 words
A process according to claims 14 or 16, wherein the oxidation effluent is contacted with a desoxygenation catalyst before contacting the CLAUS catalyst.
Claim 21
Dependent Claim
33 words
A process according to claim 1 or 14 or 16, wherein the gases issuing from the contacting of the oxidation effluent with the CLAUS catalyst are subjected to a thermal or catalytic incineration.
Claim 22
Dependent Claim
20 words
A process according to claim 1, wherein lanthanum oxide and neodymium oxide are used for thermally stabilizing the active alumina.