| 摘要 |
A feed gas stream containing at least 60% by volume of hydrogen sulphide is burnt in a first combustion region 2 to form water vapour and sulphur dioxide. Oxygen (preferably pure) is employed to support combustion in the region. Thermal reaction then takes place in thermal reaction region 10 between hydrogen sulphide and sulphur dioxide to form sulphur vapour and water vapour. The resulting gas mixture is then cooled in a waste heat boiler 12 and sulphur vapour is extracted in a condenser 14. The gas mixture then passes into a second combustion region 16 in which a further portion of the hydrogen sulphide is burnt in the presence of oxygen to form further sulphur dioxide and to adjust the mole ratio of hydrogen sulphide to sulphur dioxide to about 2:1. Further reaction between hydrogen sulphide and sulphur dioxide may be conducted in a thermal reaction region 22 and in catalytic reactors 26 and 32 with further sulphur extraction in condensers 28 and 34. The mole ratio of hydrogen sulphide to oxygen entering the combustion region 2 per unit time is greater than 2:1 and the mole ratio of hydrogen sulphide to fluid(s) (if any) other than oxygen being introduced into the region 2 is greater than 3:2 and preferably greater than 4:1. By using substantially pure oxygen to support combustion of the hydrogen sulphide, a relatively large flow rate of feed gas mixture may be handled in a plant of given size. <IMAGE> |
