Catalytic process for producing sulphur from H.sub.2 S containin

Details Catalytic process for producing sulphur from H.sub.2 S containin Catalytic process for producing sulphur from H.sub.2 S containin

1987-06-25

1990-01-16

Doll, John

Chemistry of inorganic compounds

Sulfur or compound thereof

Elemental sulfur

C01B 1704

Patent

active

048942162

DESCRIPTION:

BRIEF SUMMARY
The invention concerns a catalytic process for producing sulphur from a H.sub.2 S- containing sour gas and, more particularly, from a sour gas containing less than 25% by volume of H.sub.2 S.
In classical units for producing sulphur from a gas containing H.sub.2 S, otherwise known as sour gas, this gas is brought into a thermal reaction stage in which one third of H.sub.2 S is transformed into SO.sub.2 in the presence of oxygen or air at a temperature at least equal to 900.degree. C. The gaseous reaction mixture issued from the thermal reaction stage contains a certain quantity of elementary sulphur as well as H.sub.2 S and SO.sub.2 in a H.sub.2 S:SO.sub.2 molar ratio equal to about 2:1. This gaseous mixture is subjected to an indirect cooling to recover the calories that it contains by producing steam, and the cooled mixture is directed towards a condensation step in which the greatest proportion of the sulphur contained in the gaseous mixture is separated through condensation. In order to increase the sulphur production, which at this stage is still very incomplete, the gaseous mixture issued from the sulphur condensation step is heated then led into one or several catalytic conversion stages containing a suitable catalyst, known as a CLAUS catalyst, in contact with which SO.sub.2 reacts with H.sub.2 S to form a further quantity of sulphur. The residual gases issued from the last catalytic conversion stage are directed towards an incineration stage, of which the effluents are thereafter rejected into the atmosphere. Prior to being directed towards the incineration stage, the gases issued from the last catalytic conversion stage can be sent into a CLAUS reaction stage, called low temperature stage, comprising at least two catalytic converters mounted in parallel and operating alternately in CLAUS reaction phase, at a temperature low enough for the sulphur formed through the reaction of H.sub.2 S on SO.sub.2 to be deposited on the catalyst, then in regeneration/cooling phase through sweeping by means of a non-oxidizing gas having first a temperature comprised between 200.degree. and 500.degree. C. to vaporize the sulphur deposited on the catalyst then a temperature lower than about 160.degree. C. to cool the regenerated catalyst to the temperature required for operating the CLAUS reaction.
The utilization of a thermal reaction stage to oxidize into SO.sub.2 the required quantity of H.sub.2 S is only possible if the sour gas has a H.sub.2 S content higher than about 15 to 20% by volume and preferably at least 25% by volume. For H.sub.2 S contents of the sour gas lower than this limit, it is not possible to maintain a sufficient flame temperature, i.e. of about 900.degree. C. and above, to obtain stable combustion of H.sub.2 S without considerable and expensive modifications to the installation. Furthermore, this high temperature thermal reaction leads to transforming a proportion of the sulphur produced into COS and CS.sub.2 when the sour gas contains CO.sub.2 and/or hydrocarbons. The formation of these organic sulphur-containing compounds is prejudicial since they are only partially transformed into sulphur in the catalytic conversion stages, and this consequently contributes to reducing the overall sulphur production rate of the sulphur unit.
To allow production of sulphur from a gas having a low H.sub.2 S content, it has been proposed to modify existing conventional installations through replacing the thermal reaction stage by a catalytic oxidation stage in which the sour gas is contacted, in the presence of a H.sub.2 S oxidation catalyst in CLAUS stoichiometry, with a controlled quantity of a gas containing free oxygen to form a gaseous effluent containing H.sub.2 S and SO.sub.2 in a molar ratio substantially equal to 2:1 as well as some elementary sulphur. The said gaseous effluent is thereafter directed, after separation of the sulphur that it contains, to the catalytic conversion or/and to the low temperature CLAUS reaction stage to form a fresh quantity of sulphur, then directed towards the incinera

REFERENCES:
patent: 2889207 (1954-11-01), Eliot
patent: 3702884 (1972-11-01), Hunt et al.
patent: 4035474 (1977-07-01), Kunkel et al.
patent: 4054642 (1977-10-01), Daumas et al.
patent: 4097585 (1978-06-01), Fischer
patent: 4180554 (1982-01-01), Al-Muddaris
patent: 4309402 (1979-12-01), Goodin, Jr. et al.
patent: 4426369 (1984-01-01), Palm
patent: 4430317 (1984-02-01), Reed et al.
patent: 4436716 (1984-03-01), Kvasnikoff et al.
patent: 4462977 (1984-07-01), Reed
patent: 4469803 (1984-09-01), George
patent: 4479928 (1984-10-01), Voirin
patent: 4507275 (1985-02-01), Reed
patent: 4552746 (1985-11-01), Kettner et al.
patent: 4554534 (1985-10-01), Dupin et al.
patent: 4605546 (1986-08-01), Voirin
Translation of French Patent 2,538,716, by U.S. PTO.

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