Process for treating elemental sulphur for smell improvement

Abstract

A process for treating a stream of elemental sulphur comprising an organic polysulphide and/or a thiol for smell improvement, the process comprising the following steps: (a) providing a molten stream of elemental sulphur comprising an organic polysulphide and/or a thiol at a temperature in the range of from 120 to 160° C.; (b) admixing a liquid unsaturated compound with the stream of molten elemental sulphur in an amount in the range of from 0.01 to 10.0 wt % based on the weight of sulphur to allow the organic polysulphide and/or thiol to react with the unsaturated compound.

1 . A process for treating a stream of elemental sulphur comprising an organic polysulphide for smell improvement, the process comprising the following steps:
 (a) providing a molten stream of elemental sulphur comprising an organic polysulphide at a temperature in the range of from 120 to 160° C.;   (b) admixing a liquid unsaturated compound with the stream of molten elemental sulphur in an amount in the range of from 0.01 to 10.0 wt % based on the weight of sulphur to allow the organic polysulphide to react with the unsaturated compound; and further comprising the following steps   (c) supplying a gaseous feed stream comprising hydrogen sulphide and a thiol and a molecular-oxygen containing gas to a reaction zone comprising liquid elemental sulphur and particulate oxidation catalyst at a temperature in the range of from 120 to 160° C. to selectively oxidise hydrogen sulphide to elemental sulphur; and   (d) discharging a stream of elemental sulphur comprising an organic polysulphide from the reaction zone; wherein the stream of elemental sulphur discharged from the reaction zone in step (d) is treated according to steps (a) and (b).   
   
   
       2 . A process according to  claim 1 , wherein the unsaturated compound is a hydrocarbon. 
   
   
       3 . A process according to  claim 1 , wherein the unsaturated compound has at most 20 carbon atoms. 
   
   
       4 . A process according to  claim 2 , wherein the unsaturated compound is a hydrocarbon selected from styrene, dicyclopentadiene, 5-ethylidene-2-norbordene, 5-vinyl-2-norbordene, ethyl benzene, 1-dodecene, 1-decene, dipentene, limonene, benzene, or toluene. 
   
   
       5 . A process according to  claim 1 , wherein the unsaturated compound is a sulphur modifier. 
   
   
       6 . A process according to  claim 1 , wherein the unsaturated compound is admixed with the molten elemental sulphur in an amount in the range from 0.05 to 5.0 wt % based on the weight of sulphur. 
   
   
       7 . A process according to  claim 1 , wherein the organic polysulphide is allowed to react with the unsaturated compound for at least 5 minutes. 
   
   
       8 . A process according to  claim 1 , further comprising the following steps:
 (e) admixing the elemental sulphur treated according to steps (a) and (b) with at least any one of a sulphur cement filler, a sulphur cement modifier, or aggregate at a temperature at which sulphur is molten; and   (f) solidifying the mixture obtained by cooling the mixture to a temperature below the melting temperature of sulphur to obtain modified sulphur, sulphur cement or a sulphur cement-aggregate composite.   
   
   
       9 . A process according to  claim 8 , wherein the treated elemental sulphur is admixed in step (e) with at least a sulphur cement filler and sulphur cement or a sulphur cement-aggregate composite is obtained in step (f). 
   
   
       10 . A process according to  claim 7  , wherein the stream of elemental sulphur discharged from the reaction zone in step (d) and treated according to steps (a) and (b) comprises particulate oxidation catalyst. 
   
   
       11 . A process for treating a stream of elemental sulphur comprising an organic polysulphide and a thiol, for smell improvement, the process comprising the following steps:
 (a) providing a molten stream of elemental sulphur comprising an organic polysulphide and a thiol, at a temperature in the range of from 120 to 160° C.;   (g) admixing a liquid unsaturated compound with the stream of molten elemental sulphur in an amount in the range of from 0.01 to 10.0 wt % based on the weight of sulphur to allow the organic polysulphide and the thiol, to react with the unsaturated compound; and further comprising the following steps   (h) supplying a gaseous feed stream comprising hydrogen sulphide and a thiol and a molecular-oxygen containing gas to a reaction zone comprising liquid elemental sulphur and particulate oxidation catalyst at a temperature in the range of from 120 to 160° C. to selectively oxidise hydrogen sulphide to elemental sulphur; and   (i) discharging a stream of elemental sulphur comprising an organic polysulphide from the reaction zone; wherein the stream of elemental sulphur discharged from the reaction zone in step (d) is treated according to steps (a) and (b).   
   
   
       12 . A process according to  claim 2 , wherein the unsaturated compound has at most 20 carbon atoms. 
   
   
       13 . A process according to  claim 1 , wherein the unsaturated compound has in the range of from 4 to 14 carbon atoms. 
   
   
       14 . A process according to  claim 2 , wherein the unsaturated compound has in the range of from 4 to 14 carbon atoms. 
   
   
       15 . A process according to  claim 3 , wherein the unsaturated compound is a hydrocarbon selected from styrene, dicyclopentadiene, 5-ethylidene-2-norbordene, 5-vinyl-2-norbordene, ethyl benzene, 1-dodecene, 1-decene, dipentene, limonene, benzene, or toluene. 
   
   
       16 . A process according to  claim 12 , wherein the unsaturated compound is a hydrocarbon selected from styrene, dicyclopentadiene, 5-ethylidene-2-norbordene, 5-vinyl-2-norbordene, ethyl benzene, 1-dodecene, 1-decene, dipentene, limonene, benzene, or toluene. 
   
   
       17 . A process according to  claim 13 , wherein the unsaturated compound is a hydrocarbon selected from styrene, dicyclopentadiene, 5-ethylidene-2-norbordene, 5-vinyl-2-norbordene, ethyl benzene, 1-dodecene, 1-decene, dipentene, limonene, benzene, or toluene. 
   
   
       18 . A process according to  claim 14 , wherein the unsaturated compound is a hydrocarbon selected from styrene, dicyclopentadiene, 5-ethylidene-2-norbordene, 5-vinyl-2-norbordene, ethyl benzene, 1-dodecene, 1-decene, dipentene, limonene, benzene, or toluene. 
   
   
       19 . A process according to  claim 1 , wherein the unsaturated compound is styrene, dicyclopentadiene, 5-ethylidene-2-norbordene, 5-vinyl-2-norbordene, 1-dodecene, 1-decene, dipentene, or limonene. 
   
   
       20 . A process according to  claim 1 , wherein the unsaturated compound is admixed with the molten elemental sulphur in an amount in the range of from 0.1 to 4.0 wt % based on the weight of sulphur.