RU2501600C1 - Device to produce sulfur - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of sulfur from hydrogen sulphide bearing gases and to removing hydrogen sulphide from gases and can be used in oil processing and chemical industry. Proposed device comprises vertical cylindrical catalytic reactor, several catalyst units consisting of heat exchangers with heat carrier pathways filled with granulated catalyst, gaseous stock feed and gaseous product discharge pipes. Additionally, proposed device comprises hydrogen sulphide bearing gas steam heater, sulfur vapor condensation section and thermal siphon to withdraw reaction heat from catalyst units.

EFFECT: lower material and power input, selective oxidation.

3 dwg

Description

The invention relates to a device for producing sulfur from hydrogen sulfide-containing gases and for purifying gases from hydrogen sulfide to produce sulfur and may find application in the oil and gas, oil refining and chemical industries.

The main problem in the industrial implementation of the processes of sulfur production and gas purification from hydrogen sulfide to produce sulfur, for example, by the direct catalytic oxidation of hydrogen sulfide by oxygen to sulfur (hereinafter, direct oxidation), is the need to remove a large amount of heat released during the oxidation of hydrogen sulfide (about 2 Gcal / t). When the concentration of hydrogen sulfide is above 1.5-2 wt.% And with insufficient heat removal, the catalyst and reaction mass are locally or generally heated to a temperature above 300 ° C, at which reactions begin to undergo intensive reactions leading to the reoxidation of hydrogen sulfide with the formation of sulfur dioxide. This reduces the yield of marketable sulfur and leads to secondary pollution of the purified gas with sulfur dioxide. Local heating can also lead to deactivation or sintering of the catalyst.

The development of devices to effectively combine the chemical process of catalytic oxidation of hydrogen sulfide with the removal of reaction heat is an urgent task.

Known reactor for the implementation of gas-phase catalytic processes [RF patent No. 2393010, IPC B01J 19/24, publ. 06/27/2010], which contains a housing, input means for the starting components, means for outputting the finished product, a catalyst placement area, a heat supply or removal unit made in the form of a plurality of heat pipes passing through the catalyst placement area. Heat pipes are made in the form of wedge-shaped elements oriented radially relative to the axis of symmetry of the housing.

However, when sulfur is obtained by direct oxidation, the reactor requires equipping with additional external devices for heating the hydrogen sulfide-containing gas, for obtaining the reaction mixture from hydrogen sulfide-containing gas and oxygen-containing gas, for cooling heat pipes, and also for cooling the products of oxidation and condensation of liquid sulfur, which results in high metal consumption of the equipment generally. In addition, the reactor contains a device for intermediate input of reagents, which does not allow to effectively regulate the process by changing the concentration of the components of the reaction mixture. In addition, the design of the reactor does not allow efficiently to remove heat from the reaction zone when the concentration of hydrogen sulfide in the gas being purified exceeds 15-20% (in which the adiabatic heating of the reaction mass exceeds 500 ° C), which leads to local overheating, a decrease in the selectivity of oxidation, and a decrease in yield sulfur and pollution of the purified gas with sulfur dioxide.

The closest to the proposed device in technical essence is a catalytic reactor [RF patent No. 2371243, IPC B01J 8/00, publ. October 27, 2009], adopted as a prototype. The reactor is made in the form of a vertical cylindrical apparatus, inside of which one or more catalyst blocks of heat transfer (heat exchange) elements are installed. Each block is formed by spiral-shaped heat transfer elements that form two channels for working media - axial and radial-spiral. The reaction mass passes through an axial channel filled with a fine-grained (granular) catalyst, and a coolant passes through a radial-spiral channel (inner space), which ensures uniform heat removal of the exothermic reaction. In addition, the reactor is equipped with nozzles for introducing gaseous raw materials and outputting the gaseous product.

However, the reactor requires equipping with additional external devices for heating the hydrogen sulfide-containing gas, for cooling and condensing liquid sulfur, to obtain a reaction mixture of hydrogen sulfide-containing gas and oxygen-containing gas, which leads to a large metal consumption of the equipment as a whole. The reactor also does not provide devices for the intermediate input of reagents, which does not allow to regulate the process by changing the concentration of reaction components. In addition, the design of the reactor is not applicable when the concentration of hydrogen sulfide in the gas to be cleaned is more than 25-30% (while the adiabatic heating of the reaction mass exceeds 800 ° C), which also leads to a decrease in the selectivity of oxidation of hydrogen sulfide, a decrease in the yield of sulfur and pollution of the purified gas with sulfur dioxide.

The objective of the invention is to reduce the material consumption of equipment, reduce energy consumption, increase the selectivity of oxidation of hydrogen sulfide.

The technical result that can be obtained by implementing the method:

- reduction of material consumption by reducing the number of pieces of equipment and catalyst loading,

- reduction of energy consumption due to the lack of heat consumption for primary and re-heating of the reaction mixture, as well as due to the possibility of removal of high potential heat (in the form of low and high pressure water vapor or heated coolant) from the reactor for the needs of third-party consumers,

- increasing the selectivity of oxidation of hydrogen sulfide by preventing local overheating of the catalyst.

The specified technical result is achieved by the fact that in the known device for producing sulfur, comprising a vertical cylindrical catalytic reactor containing several catalyst units consisting of heat exchange elements with an internal space for the passage of coolant, the space between which is filled with a granular catalyst, as well as nozzles for introducing gaseous raw materials and output of the gaseous product, the feature is that the device further comprises a steam heater with a hydrogen-containing gas, a sulfur vapor condensation section and a thermosiphon device for removing reaction heat from the catalyst blocks, the reactor comprising nozzles for introducing hydrogen sulfide-containing gas, withdrawing purified gas and liquid sulfur, introducing circulating liquid sulfur, and nozzles for introducing oxygen-containing gas, catalyst blocks equipped with devices for the distribution of oxygen-containing gas over the cross section of the apparatus, thermosiphon device consists of a collector-distributor of liquid coolant, collector a-collector of the vapor-liquid mixture and the separation space in which the steam heater of hydrogen sulfide-containing gas is placed, and the sulfur condensation section is located below the catalyst section and consists of a surface sulfur vapor condenser, including irrigated and cooled condensation surfaces located at an angle of 10-90 degrees to the horizontal, and devices for distributing circulating liquid sulfur over condensation surfaces, as well as a washing gas washing unit for circulating liquid sulfur, equipped with rotivotochnoy mass transfer packing.

Additional equipment of the device with a steam heater, condensation section and thermosiphon device allows to reduce the number of pieces of equipment and reduce the metal consumption of the equipment.

Equipping the reactor with nozzles for introducing hydrogen sulfide-containing gas, withdrawing purified gas and liquid sulfur, introducing circulating liquid sulfur, and also for introducing oxygen-containing gas allows raw materials to be introduced separately along the height of the reactor and, thereby, to adjust the ratio of components in each catalytic unit, as well as to remove products reactions.

The presence in the catalyst blocks of devices for distributing oxygen-containing gas over the cross section of the apparatus provides a uniform load on the catalyst over the cross section of the apparatus, thereby increasing the selectivity of oxidation and reducing the load of the catalyst.

The presence of a thermosiphon device consisting of a collector-distributor of liquid coolant, a collector-collector of a vapor-liquid mixture located at the level of the catalyst blocks, and a separator located at the top of the reactor, in which a steam heater of hydrogen sulfide-containing gas is placed, provides not only effective heat removal from the catalyst blocks, but and allows you to heat the raw hydrogen sulfide gas to a temperature of direct oxidation.

The location of the sulfur condensation section below the catalyst section allows gravity to be withdrawn by gravity.

The use of a surface sulfur vapor condenser containing irrigated and cooled condensation surfaces located at an angle of 10-90 degrees to the horizontal, and a device for distributing circulating liquid sulfur along condensation surfaces makes it possible to avoid the formation of finely dispersed sulfur aerosol in the purified gas.

And the presence of a purified gas washing unit with circulating liquid sulfur, equipped with a countercurrent mass transfer nozzle, makes it possible to remove residual sulfur aerosol from the purified gas.

The reactor consists of catalyst blocks 1 (two blocks are conventionally shown), a thermosiphon device 2, and a sulfur vapor condensation section 3 (Fig. 1).

Each of several catalyst blocks 1 (a cross section of the block is shown in FIG. 2) contains heat exchange elements 4, through the inner space 5 of which there is a heat carrier and a granular catalyst 6 placed between them, a collector-distributor of raw materials 7 and a collector of reaction products 8, and equipped with a device 9 for distributing oxygen-containing gas over the cross section of the apparatus and a pipe for introducing oxygen-containing gas 10.

Thermosiphon device 2 contains a collector-distributor of liquid coolant 11, a collector-collector of vapor-liquid mixture 12 and a separation space 13, in the inner space of which there is a steam heater of hydrogen sulfide-containing gas 14 and a vapor condenser of the coolant 15.

The steam heater 14 is equipped with a pipe for introducing hydrogen sulfide-containing gas 16 and is connected by a pipe 17 to the catalytic section.

The sulfur vapor condensation section 3 (Fig. 3) consists of a surface sulfur vapor condenser 18, including irrigated and cooled condensation surfaces located at an angle of 10-90 degrees to the horizontal, a switchgear 19 for supplying circulating liquid sulfur to the condensation surfaces, with a pipe for introducing circulating liquid sulfur 20, as well as a washing unit for oxidation products of circulating liquid sulfur 21, equipped with a countercurrent mass transfer nozzle 22. In addition, there are nozzles 23 for outputting purified gas and Displayed liquid sulfur 24.

The proposed device operates as follows.

In the pipe 16 of the steam heater 14 serves hydrogen sulfide-containing gas I, it is heated to a temperature of "ignition of the reaction" of about 200 ° C due to the heat of condensation of the vapor in the separation space of the thermosyphon device 2 and sent to the catalytic section through the pipe 17.

Oxygen-containing gas II is introduced through nozzles 10, distributed over the apparatus cross section using devices 9, mixed with hydrogen sulfide-containing gas I, and then comes into contact with granular catalyst 6 located between the heat exchange elements 4 of catalyst blocks 1. As a result of the exothermic oxidation of hydrogen sulfide, oxidation products are formed containing sulfur vapor, and the heat of reaction due to the evaporation of the liquid coolant III is transferred to the inner space of the heat exchanger elements 5, evaporating boiling heat ositel directed further into a vapor-liquid mixture IV through the collector-distributor 11 into the separation space 2 thermosyphon device.

In the separation space, the liquid part of the coolant V is separated from its vapors, which are cooled by heating the hydrogen sulfide-containing gas I in the steam heater 14, and also by heating the coolant III in the condenser 15 and condense to form an additional amount of the coolant supplied under its own pressure through the collector -distributor of liquid coolant 11 into the inner space 5 of the heat exchange elements 4.

Sulfur vapors contained in oxidation products IV condense as saturation pressure is reached and liquid sulfur flows into the condensation section of sulfur vapors 3, where it is cooled on the condensation surfaces of surface condenser 18, additionally irrigated with circulating liquid sulfur VI entering through pipe 20 and distribution device 19 . Sulfur vapor that does not condense in the catalytic section condenses on the cooled liquid sulfur film. Liquid sulfur VII is removed from the pipe 24 located at the bottom of the device.

The cooled gas VIII is additionally washed with circulating liquid sulfur VI on the countercurrent mass transfer nozzle 22 and their reactor is withdrawn through the purified gas pipe 23.

As a coolant, a high-temperature coolant is used, boiling at a temperature of 200-250 ° C (at atmospheric pressure), for example, water or a dauther.

The proposed device can find application in the oil and gas, oil refining and chemical industries.

Claims (1)

A device for producing sulfur, comprising a vertical cylindrical catalytic reactor containing several catalyst units consisting of heat exchange elements with an internal space for the passage of coolant, the space between which is filled with granular catalyst, as well as nozzles for introducing gaseous raw materials and outputting a gaseous product, characterized in that the device further comprises a steam heater of a hydrogen sulfide-containing gas, a sulfur vapor condensation section and a thermosiphon device a device for removing reaction heat from the catalyst blocks, wherein the reactor contains nozzles for introducing hydrogen sulfide gas, removing purified gas and liquid sulfur, introducing circulating liquid sulfur, and nozzles for introducing oxygen-containing gas, while the catalyst blocks are equipped with oxygen-containing gas distribution devices section of the apparatus, thermosiphon device consists of a collector-distributor of liquid coolant, a collector-collector of a vapor-liquid mixture and a separation space, into The rum contains a steam heater of hydrogen sulfide-containing gas, and the sulfur vapor condensation section is located below the catalyst blocks and consists of a surface sulfur vapor condenser, including irrigated and cooled condensation surfaces located at an angle of 10-90 degrees to the horizontal, and devices for distributing circulating liquid sulfur over the condensation surfaces, as well as the cleaning gas washing unit with circulating liquid sulfur, equipped with a countercurrent mass transfer nozzle.

Images