CN1774396A

CN1774396A - The manufacture of carbonyl sulphide

Info

Publication number: CN1774396A
Application number: CNA2004800091560A
Authority: CN
Inventors: 维斯顿·戴维·芬科
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-04-10
Filing date: 2004-04-13
Publication date: 2006-05-17
Also published as: GB0308283D0; WO2004089824A1

Abstract

A method of producing carbonyl disulphide is disclosed in which sulphur entering a vessel (24.1) along a line (22.1) is dissolved in liquid carbon disulphide entering along a line (26.1). In a reactor (140) the dissolved sulphur and carbon disulphide is reacted with carbon entering along a line (14.1) and solid carbon entering along a line (10.1). The reaction products are fed along a line (14.1) to a scrubber (146) and then to a distillation column (104.1). The gaseous fraction which emerges from the column (104.1), and which consists mainly of carbonyl sulphide, is cooled in two refrigeration stages (124.1, 126.1) and stored in a tank (132.1). Carbon disulphide is recovered from the column (104.1) and stored in a tank (118.1) for eventual return to the vessel (24.1) along the line (26.1).

Description

Process for producing carbonyl sulfide

[ field of the technology]

The present invention relates to a process for the manufacture of carbonyl sulphide, also commonly referred to as carbonyl sulphide.

[ background art]

Carbon oxysulfide, commonly referred to as "COS", is commonly used as a raw material for fumigation, for example, in silos, and is gradually replacing earlier fumigants that were considered to be ecologically undesirable.

Commercially, Carbon Oxysulfide (COS) is generally produced via two processes. The first method involves reacting carbon monoxide with molten sulphur in a reaction vessel, the carbon monoxide bubbling through the molten sulphur. Molten sulphur is a dangerous, aggressive substance and therefore requires special reaction vessels. Moreover, carbon monoxide is a relatively costly gas. As a result of these factors, the resulting carbonyl sulfide (COS) is relatively expensive.

A second method of manufacture of carbonyl sulphide, known to the applicant, comprises producing a boiling sulphur base layer in particulate form and reacting the sulphur base layer with carbon monoxide. The sulphur used is usually in the form of iron sulphide ore, and the residue is thus iron containing important sulphur species and cannot be used as a raw material in iron smelting processes.

At the same time, the process allows to obtain a cheaper carbonyl sulphide product compared to the first process described, but the carbonyl sulphide (COS) produced according to the process is still more expensive.

If manufactured at a lower cost, carbonyl sulfide (COS) will be more widely used as a fumigant feedstock than is currently available and has significant ecological impact.

Accordingly, the present invention seeks to provide a process for the production of Carbon Oxysulfide (COS) products which is less expensive than the processes currently used commercially.

[ summary of the invention]

The invention provides a process for producing carbonyl sulfide, which comprises, in the first stage, dissolving sulfur in carbon sulfide, and, in the second stage, reacting the sulfur solution in carbon sulfide with carbon substances and oxygen atoms.

The process of the invention may include the step of reacting the sulphur solution in the carbon sulphide with the carbon material and the carbon dioxide. As an optional step, the process may comprise reacting carbon dioxide with oxygen to obtain carbon monoxide, and reacting the carbon monoxide produced with a sulphur solution of carbon sulphide.

The carbon disulphide may be separated from the carbonyl sulphide, for example by feeding the carbonyl sulphide and carbon dioxide to a distillation column.

The process of the present invention may include the further step of cooling the carrier of carbonyl sulphide and iron sulphide using a spray of liquid carbon sulphide and/or a bath of carbon disulphide.

In a particular form of the process of the invention, the process comprises a cooling step of cooling the carbonyl sulphide and the carbon dioxide carrier using a spray of liquid carbon sulphide and/or a bath of liquid carbon disulphide, and feeding the carbonyl sulphide and the carbon sulphide contained therein from the cooling stage to a distillation column in which separation of the carbon sulphide from the carbonyl sulphide takes place.

The separated carbon sulphide may be recycled in said first stage.

The process of the present invention may further comprise the step of cooling the carbonyl sulphide formed in the distillation column to produce a stream of carbonyl sulphide which is returned to the distillation column and a stream of carbonyl sulphide.

As a final process step in the process, the carbon oxysulfide gas stream can be liquefied.

[ description of the drawings]

For a better understanding of the invention and to describe how the method of the invention can be carried into effect, reference will now be made in detail to specific embodiments thereof with reference to the accompanying drawings. Wherein:

FIGS. 1 and 2 each show a plant layout for a Carbon Oxysulfide (COS) product;

FIG. 3 is a detailed illustration of the plant arrangement shown in FIGS. 1 and 2;

figure 4 shows a plant set-up for another Carbon Oxysulfide (COS) product.

In the drawings:

the lines 10, 16, 22, 26, 38, 42, 96, 106, 128, 130, 148,

the reactors 12, 62, 64, 140, the heat exchangers 18, 80,

a sulfur supply device 20, a container 24, a stirring blade 28,

three layers of reaction vessels 30, 32, 34,

inlets

36, 40

The cooling jackets 44, 52, 58 are,

conduits 48, 50, 54, 56, 60, 66, 68, 70, 72, 74, 76, 78, 82, 86, 92, 110, 112, 92.1,

the oil tanks 84, 132, the coolant reservoir 88,

outlets 94, 100, 102, 13q4, condenser 98,

the distillation columns 104, 104.1, the reboiler 108,

coolers 114, 116, 124, 126, 124.1, 124.2, storage tank 118,

the pump 120, the cooling water circuit 122,

the carbon dioxide cylinders 136, 138, the compressors 142, 144,

wash the cooling vessel 146, bathroom 150.

[ detailed description of the invention]

Referring first to fig. 1, a carbon material, such as carbon in the form of carbon black, is fed by a screw conveyor along line 10 to a reactor 12. Carbon dioxide is injected into the reactor 12 along line 16. At this time, the reactions occurring in the reactor 12 are:

a line 16 leads from the reactor 12 to a heat exchanger 18 so that the carbon monoxide produced is cooled in the heat exchanger 18.

Numeral 20 generally indicates a supply device for supplying sulphur dissolved in carbon disulphide. Sulphur, in solid form, is fed by a screw conveyor along line 22 into a vessel 24 and carbon sulphide in liquid form is supplied along line 26 into the vessel 24. The vessel 24 is shown schematically as having stirring blades 28 for agitating the liquid carbon sulphide so that the solid sulphur dissolves therein.

The temperature of the liquid exiting the container 24 is about 25 degrees celsius.

A three-stage reaction vessel 30, 32 and 34 is provided for reacting dissolved sulphur with carbon monoxide produced in the reactor 12. The first stage reactor vessel 30 is provided with an inlet 36, wherein a line 38 leads from the heat exchanger 18 to the inlet 36. The first layer of reaction vessels 30 is further provided with a further inlet 40, wherein a line 42 is connected thereto, and the line 42 leads from the vessel 24 into the reaction vessel 30.

The arrangement of

inlets

36 and 40 is shown in FIG. 3, with FIG. 3 also showing oil cooling shroud 44. The diameter of the flow path increases downstream of the inlet 40.

The three reaction vessels (the first reaction vessel 30, the second reaction vessel 32, and the third reaction vessel 34) are connected in series via the conduit 48 and the conduit 50.

The liquid coolant is pumped along a conduit 54 into the cooling jacket 52 of the third layer of reaction vessels 34. From said cooling hood 52, the cooling liquid flows along a further conduit 56 into a cooling hood 58 of the second tier reaction vessel 32. And a further conduit 60 connects the cooling jacket 52 to the cooling jacket 44 (shown in figure 2).

From the third stage 34, the mixture of gaseous Carbon Oxysulfide (COS) and gaseous carbon disulfide further flows into a two-stage reactor 62, 64. The two reactors 62, 64 are connected in series with each other by a conduit 66.

The two-tier reactors 62, 64 are identical to the three-tier reaction vessels 30, 32, 34 and include cooling jackets through which coolant is pumped, with the inlet conduit for coolant being indicated at 68.

The main reactions that occur in the three-tier reaction vessels 30, 32, 34 and the two-tier reactors 62, 64 are:

the auxiliary reaction is then:

the liquid coolant circuit is shown in fig. 1 and includes conduits 54, 56, 60 and 68, as well as a conduit 70 leading to heat exchanger 18.

Return coolant conduits are identified by numerals 72, 74 and 76 and are connected to conduit 78, conduit 78 and extend in a single conduit to heat exchanger 80. Wherein the heat exchanger 80 is used to dissipate the excess heat. A conduit 82 leads from the heat exchanger 80 to a reservoir 84, where the solid matter settles into the reservoir 84. A further conduit 86 leads from the tank 84 to a coolant reservoir 88 into which reservoir 88 excess coolant flows as it expands due to heating.

An outlet conduit 92 leads from the tank 84 to the heat exchanger 18 and includes a manifold for supplying coolant to the heat exchanger 18, the three-stage reaction vessels 30, 32, and 34, and the two-stage reactors 62, 64.

Finally the outlet of the reactor 64 is identified at 94. Wherein line 96 is connected to outlet 94 and leads to condenser 98 (see fig. 2). The condenser 98 is provided with an outlet 100 for the gaseous part and an outlet 102 for the liquid part. The outlets 100 and 102 are connected to a distillation column 104.

In the column 104, a gas fraction mainly composed of iron oxysulfide (COS) rises, and a liquid fraction mainly composed of liquid iron disulfide flows toward the lower portion of the column 104.

The liquid portion from the split distillation column 104 flows along line 106 to reboiler 108, where reboiler 108 has been injected with hot liquid along conduit 110. Carbon Oxysulfide (COS) in the reheated liquid returned to the column 104 rises from the condenser 108 into the column 104 and is rejuvenated, numeral 112.

A liquid level detector is provided in the distillation column 104. When the detector detects that the highest level of carbon sulfide in the distillation column 104 has reached a predetermined level, the liquid carbon sulfide is transferred to the coolers 114, 116 before reaching the storage tank 118.

The carbon sulfide in the storage tank 118 will eventually be returned to the line 26 by the pump 120 and recycled.

The cooling water circuit 122 includes a radiator for supplying cooling water to the coolers 114, 116, which also provides cooled water to the condenser 98.

The gas portion selected from the upper end of the splitter distillation column 104 contains carbonyl sulfide and carbon sulfide species and passes through two gas coolers 124, 126. The carbonyl sulfide liquefies when the first cooler 124 cools to a temperature above which the carbonyl sulfide liquefies, and below which the carbonyl sulfide liquefies. The liquefied carbon sulfide is returned to the distillation column 104 along line 128. In the second cooler 126, the carbonyl sulfide is cooled until liquefied. Liquid Carbon Oxysulfide (COS) is fed from the second stage along line 130 into tank 132, while other gases, such as carbon dioxide and carbon monoxide, are removed through outlet 134.

The carbon dioxide cylinder vessels are identified by numerals 136 and 138, the cylinder vessels 136, 138 being used to supply gas to the cooling vessels 124, 126.

Referring to fig. 4, the Carbon Oxysulfide (COS) plant arrangement shown in fig. 4 shares many features with the arrangement shown in fig. 1 and 2. Thus, where applicable, like reference numerals have been used, with the suffix 1.

The reactor 140 includes a carbon substrate disposed within a metal container that is lined with refractory material to resist the heat generated by the exothermic reaction. The conduit 92.1 supplies coolant to the reactor 140. In fig. 1 and 2, the reactions occurring in the reactor 12 and the three-layer reaction vessels 30, 32, and 34 all occur in the reactor 140.

The coolers 124.1 and 124.2 are powered by two compressors 142, 144.

Between the reactor 140 and the distillation column 104.1, a scrubbing and cooling vessel 146 for scrubbing and cooling is provided. A line 148 connects the reactor 140 to the scrubber cooling vessel 146. A bath 150 of liquid carbon disulphide is provided in the lower part of the scrubbing and cooling vessel 146. The liquid is withdrawn from the scrubber cooling vessel 146, sprayed through the heat exchanger 98.1 and returned to the upper end of the scrubber cooling vessel 146 as a spray of cooled carbon disulphide liquid.

The reaction products produced from the reactor 140 enter the upper or lower portion of the liquid level in the scrubber cooling vessel 146. If these reaction products enter the lower part of the liquid level they first bubble through the liquid and then flow in the opposite direction into the falling carbon disulphide spray. If the reaction products enter the upper part of the liquid level, they flow in the opposite direction into the falling spray.

Elemental sulphur in the reaction product is dissolved into the liquid carbon disulphide and this prevents sulphur coatings from building up inside the distillation column 104.1 and elsewhere in the plant.

Claims

1. A method of producing carbonyl sulfide, the method comprising: in a first stage, dissolving sulphur species into carbon sulphide; and in the second stage, the sulfur solution in the carbon sulfide is reacted with carbon element and oxygen atom.

2. A process for the production of carbonyl sulphide as claimed in claim 1, comprising the step of reacting a solution of sulphur in carbon sulphide with elemental carbon and carbon dioxide.

3. The process for the production of carbon oxysulfide according to claim 1, comprising the steps of reacting carbon dioxide with oxygen to provide carbon monoxide; and reacting the generated carbon monoxide with a sulphur solution in carbon sulphide.

4. A process for the production of carbonyl sulfide as claimed in claim 1, 2 or 3, further comprising the step of separating the carbon sulfide from the carbonyl sulfide.

5. A process for the production of carbonyl sulfide as claimed in claim 4, wherein it comprises feeding carbonyl sulfide and carbon sulfide into a distillation column for separating carbon sulfide from carbonyl sulfide.

6. A process for the production of carbonyl sulfide as claimed in claim 1, 2, 3 or 4, wherein it comprises cooling the carbonyl sulfide and carbon sulfide carrier by spraying liquid carbon sulfide and/or a bath of carbon disulfide liquid.

7. A process for the production of carbonyl sulphide as claimed in claim 1, 2 or 3, which comprises cooling a carrier of carbonyl sulphide and carbon dioxide using a spray of liquid carbon sulphide and/or a bath of carbon disulphide liquid, and feeding carbonyl sulphide and the carbon sulphide contained therein from the cooling stage to a distillation column in which the carbon sulphide is separated from the carbonyl sulphide.

8. A process for the manufacture of carbonyl sulphide as claimed in claim 4, 5, 6 or 7, characterized in that it comprises a step of recycling the separated carbonyl sulphide to the first stage.

9. The process of claim 7, including cooling the carbonyl sulfide produced from the distillation column to produce a spray of carbonyl sulfide for reflux to the distillation column and producing a stream of carbonyl sulfide.

10. The process for the production of carbonyl sulfide as claimed in claim 9, further comprising the step of liquefying the carbonyl sulfide.