CA1077677A - Process for preparing sulfur dioxide from sulfur and oxygen - Google Patents
Process for preparing sulfur dioxide from sulfur and oxygenInfo
- Publication number
- CA1077677A CA1077677A CA231,243A CA231243A CA1077677A CA 1077677 A CA1077677 A CA 1077677A CA 231243 A CA231243 A CA 231243A CA 1077677 A CA1077677 A CA 1077677A
- Authority
- CA
- Canada
- Prior art keywords
- sulfur
- oxygen
- sulfur dioxide
- wall
- preparing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/48—Sulfur dioxide; Sulfurous acid
- C01B17/50—Preparation of sulfur dioxide
- C01B17/54—Preparation of sulfur dioxide by burning elemental sulfur
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
PROCESS FOR PREPARING SULFUR DIOXIDE FROM
SULFUR AND OXYGEN
Abstract of the disclosure:
Sulfur dioxide is prepared by combining and burning liquid sulfur in finely dispersed form and oxygen without dilution by sulfur dioxide. The molar proportion of O2/S
is about 1.0 to 1.55.
SULFUR AND OXYGEN
Abstract of the disclosure:
Sulfur dioxide is prepared by combining and burning liquid sulfur in finely dispersed form and oxygen without dilution by sulfur dioxide. The molar proportion of O2/S
is about 1.0 to 1.55.
Description
1~77~77 The present invention relates to a process for preparing sulfur dioxide from liquid sulfur by combustion of the sulfur using technically pure oxygen.
It is known to prepare sulfur dioxide on an industrial scale by total or partial condensation or by hydraulic washing (Grillo process~ of sulfur combustion gases containing S02 or of gases from roasting; Air being used as the oxidant for the combustion.
It is also known to burn fine grained powdered sulfur ~cf. German Reichs patent No. 191,956) or vapours sulfur ~cf. German Reichs patent No.
437,910) with oxygen. According to this process an excess of sulfur causes a reduction of the reaction temperature. Sulfur may also be burnt by intro-ducing bubbles of heated oxygen into liquid sulfur ~cf. German Reichs patent No. 539,640), especially by means of an immersion heater ~cf. German Reichs patent No. 711,537).
German Offenlegungsschrift No. 2,159,790 discloses a process for partially burning sulfur with oxygen by admixing S02, wherein the maximal combustion temperatures are at 2000C. German Offenlegungsschrift No.
It is known to prepare sulfur dioxide on an industrial scale by total or partial condensation or by hydraulic washing (Grillo process~ of sulfur combustion gases containing S02 or of gases from roasting; Air being used as the oxidant for the combustion.
It is also known to burn fine grained powdered sulfur ~cf. German Reichs patent No. 191,956) or vapours sulfur ~cf. German Reichs patent No.
437,910) with oxygen. According to this process an excess of sulfur causes a reduction of the reaction temperature. Sulfur may also be burnt by intro-ducing bubbles of heated oxygen into liquid sulfur ~cf. German Reichs patent No. 539,640), especially by means of an immersion heater ~cf. German Reichs patent No. 711,537).
German Offenlegungsschrift No. 2,159,790 discloses a process for partially burning sulfur with oxygen by admixing S02, wherein the maximal combustion temperatures are at 2000C. German Offenlegungsschrift No.
2,223,131 discloses a process for burning sulfur with oxygen or with oxygen enriched air while simultaneously recycling cold S02 to the sulfur combustion chamber.
The processes already carried out on an industrial scale require a high energy expenditure (total condensation of S02 in the presence of large quantities of inert gas or in combination with an oxidation or absorption plant in the case of the partial condensation of sulfur dioxide). The cited processes also demand high investment costs and are only suitable for plants having a daily maximum output of 1~ to 20 tonnes of sulfur per combustion unit. It is important for processes operating in the presence of air to main-tain the temperature in a range where the formation of nitric oxides is aslow as possible. In the process of German Offenlegungsschrift No. 2,159,790 operating - . : . . .: . -, .
: . . : . . -.. . . .
, .. ..
., -:
..
1(~77677 with oxygen several steps are used in order to assure that theoretical com-bustion temperatures of about 3000C are not produced; processes providing a combustion in several steps, however, demand high investment costs.
Accordingly, it would be advantageous to prepare pure sulfur dioxide on a large scale in a manner as cheap as possible by oxidizing sulfur with technically pure oxygen. The present invention is based on the problem of avoiding the inconveniences of the known technical processes. It should be possible to obtain a combustionof more than 99.9% in one step with a stoichiometric proportion within the accuracy of measurement of the products used as starting components.
Accordingly, the present invention provides a process for preparing sulfur dioxide from liquid sulfur and oxygen which comprises combining and burning technically pure oxygen containing at least 70% by volume 2 and finely dispersed liquid sulfur using a two component nozzle burner or a rotation burner without dilution by sulfur dioxide, the molar proportion of 02/S bèing about 1.0 to 1.55, collecting the hot gases in a combustion chamber having a heat resistant wall, the outer side of said wall being cooled and the inner side of said wall having a temperature of at least 1200C and subsequently cooling the hot gases. Under technically pure oxygen there is especially to be understood oxygen having an 2 content, of more than 90% by volume. The higher the 2 content is, the less is the ballast gases which must be fully separated from the S02 for~ed. Pure S02 may be condensed from the sulfur combustion gas by cooling. The combustion gas may also be further worked up without separating liquid SO2 by condensation. In this case, it is sufficient to cool the combustion gas to the temperature required for the further working up (for example to a temperature of 450C for preparing SO3).
Simultaneously, the heat of reaction may also be utilized for the economic -production of steam. The process may be carried out a~ elevated pressure, but this does not considerably reduce the costs of the process, especially with
The processes already carried out on an industrial scale require a high energy expenditure (total condensation of S02 in the presence of large quantities of inert gas or in combination with an oxidation or absorption plant in the case of the partial condensation of sulfur dioxide). The cited processes also demand high investment costs and are only suitable for plants having a daily maximum output of 1~ to 20 tonnes of sulfur per combustion unit. It is important for processes operating in the presence of air to main-tain the temperature in a range where the formation of nitric oxides is aslow as possible. In the process of German Offenlegungsschrift No. 2,159,790 operating - . : . . .: . -, .
: . . : . . -.. . . .
, .. ..
., -:
..
1(~77677 with oxygen several steps are used in order to assure that theoretical com-bustion temperatures of about 3000C are not produced; processes providing a combustion in several steps, however, demand high investment costs.
Accordingly, it would be advantageous to prepare pure sulfur dioxide on a large scale in a manner as cheap as possible by oxidizing sulfur with technically pure oxygen. The present invention is based on the problem of avoiding the inconveniences of the known technical processes. It should be possible to obtain a combustionof more than 99.9% in one step with a stoichiometric proportion within the accuracy of measurement of the products used as starting components.
Accordingly, the present invention provides a process for preparing sulfur dioxide from liquid sulfur and oxygen which comprises combining and burning technically pure oxygen containing at least 70% by volume 2 and finely dispersed liquid sulfur using a two component nozzle burner or a rotation burner without dilution by sulfur dioxide, the molar proportion of 02/S bèing about 1.0 to 1.55, collecting the hot gases in a combustion chamber having a heat resistant wall, the outer side of said wall being cooled and the inner side of said wall having a temperature of at least 1200C and subsequently cooling the hot gases. Under technically pure oxygen there is especially to be understood oxygen having an 2 content, of more than 90% by volume. The higher the 2 content is, the less is the ballast gases which must be fully separated from the S02 for~ed. Pure S02 may be condensed from the sulfur combustion gas by cooling. The combustion gas may also be further worked up without separating liquid SO2 by condensation. In this case, it is sufficient to cool the combustion gas to the temperature required for the further working up (for example to a temperature of 450C for preparing SO3).
Simultaneously, the heat of reaction may also be utilized for the economic -production of steam. The process may be carried out a~ elevated pressure, but this does not considerably reduce the costs of the process, especially with
- 3 _ --- ~- . . .. . .
- . . . . . . ..
'. ' . . ' ' . . ~ ,' :'' , ~, ........ ' , ~ :
.
respect to the heat e~changer~radiation part of the boiler~ where the released reaction heat is utilized. The process is preferably operated under a pres-sure of 1 to 7 bars. The process of the present invention disperses with cooling by using recycled cold sulfur dioxide.
A molar proportion of 02/S of about 1.55 is advantageous used espe-cially in the case where SO3 is to the final product produced from the sulfur.
It is quite surprising considering German Offenlegungsschriften 2,159,790 and 2,223,131 that the flame temperatures do not exceed 2000C in the combustion of stoichiometrical mixtures of S/02. An equilibrium obviously is produced at high temperatures preventing a complete reaction. The rest of the reaction would be effected synchronously with the cooling of the flama gases.
According to the process of the present invention only small quantities of sulfur trioxide are observed in the sulfur dioxide gas.
However, it is nevertheless recommended for the production of technically pure S02 to connect a washing colunnafter the steam boiler filled with 99% sulfuric acid to absorb the residual contents of SO3 and to further cool the gas to a temperature of from 40 to 80C. The small quantities of any excess oxygen are recovered in the condensation of the sulfur dioxide and admixed with fresh oxygen.
Since only small gas volumes are used in the process of the present invention, only a small apparatus is needed; the output however being high. Accordingly, the investment costs for plants operating according to the process of the present invention are relatively low. The quantity of sulfuric acid necessarily obtained can be minimized (about 1 kg/100 kg of SO2) owing to the small portion of SO3 in S02. The output of inert gas introduced in small amounts with the technically pure oxygen can also be rendered insignificant. It is, moreover, possible to free these small quantities from SO2 by washing them, for example, with sodium hydroxide so-lution so that noxious emissions do not occur.
`~
- . . . . . . ..
'. ' . . ' ' . . ~ ,' :'' , ~, ........ ' , ~ :
.
respect to the heat e~changer~radiation part of the boiler~ where the released reaction heat is utilized. The process is preferably operated under a pres-sure of 1 to 7 bars. The process of the present invention disperses with cooling by using recycled cold sulfur dioxide.
A molar proportion of 02/S of about 1.55 is advantageous used espe-cially in the case where SO3 is to the final product produced from the sulfur.
It is quite surprising considering German Offenlegungsschriften 2,159,790 and 2,223,131 that the flame temperatures do not exceed 2000C in the combustion of stoichiometrical mixtures of S/02. An equilibrium obviously is produced at high temperatures preventing a complete reaction. The rest of the reaction would be effected synchronously with the cooling of the flama gases.
According to the process of the present invention only small quantities of sulfur trioxide are observed in the sulfur dioxide gas.
However, it is nevertheless recommended for the production of technically pure S02 to connect a washing colunnafter the steam boiler filled with 99% sulfuric acid to absorb the residual contents of SO3 and to further cool the gas to a temperature of from 40 to 80C. The small quantities of any excess oxygen are recovered in the condensation of the sulfur dioxide and admixed with fresh oxygen.
Since only small gas volumes are used in the process of the present invention, only a small apparatus is needed; the output however being high. Accordingly, the investment costs for plants operating according to the process of the present invention are relatively low. The quantity of sulfuric acid necessarily obtained can be minimized (about 1 kg/100 kg of SO2) owing to the small portion of SO3 in S02. The output of inert gas introduced in small amounts with the technically pure oxygen can also be rendered insignificant. It is, moreover, possible to free these small quantities from SO2 by washing them, for example, with sodium hydroxide so-lution so that noxious emissions do not occur.
`~
- 4 -: . , - . - -.
1077~7~7 The flame may be produced by used burners which enable the sim-ultaneous introduction of liquid sulfur and oxygen such as two components nozzle burners as well as rotation burners. The proportion of liquid sulfur and oxygen is not cirtical. The process may be operated with stoichio-metrical quantities, with a slight excess of 2 (for example of up to 7%) or, if the sulfur dioxide formed is to be further oxidized to give SO3, with a higher excess of 2 of about 55%. In all cases the measured maximal temperaturesof the flame are at about 2000C.
The invention will now be illustrated by way of example using the accompanying drawing which depicts a flow scheme. The hot gases produced in the burner (1) are collected in a combustion chamber (2) having heat resistant walls. Chambers lined with highly fire-proof stones have proved particularly successful. The walls are advantageously cooled on the outside. Uncoated steel tubes which are cooled may also be used; the good heat tranfer, however, results in a rapid temperature decrease of the reaction gases and, consequently,in a possible residual content of unburnt sulfur. The thickness of the wall lining must be such that the inner wall temperature is at least 1200C, pre-ferably from 1400 to 1500C. In this case the temperature of the zone of in-candenscence formed at the wall is still so high that inspite of the outside cooling a sufficient quantity of sulfur is still burnt. Only in the case of small sulfur outputs i.e. in the case of sulfur outputs substantially smaller ; than those just obtainable in a given appratus the process may be operated from time to time without outside cooling owing to the backflow of the cooled flame gases. The combustion gas only contains a small quantity of SO3 (of about 0.1 to 1% by volume). A heat exchanger preferably consisting of a radiator and a convection part is connected after the reactor (3) in order to utilize the reaction heat. In order to control the temperature of the waste gas in the case of varying charges the cooling surfaces may be ad-vantageously subdivided. Cooling of the combustion gases to about 280 to ; ,~.
_ 5 _ ' ~ , ', : --.' ' .
,:
iO77~77 100C may be effected, for example, in an economizer (not illustrated in thedrawing). Thereby the feeding water of a steam producing boiler is heated at the pressure side of the pump. The combustion gas is then further cooled to about 40C in the following sulfuric acid washer (4). The small S03 content is simultaneously removed thereby. Pure S02 is precipitated in a liquid form in the condenser (5) by brine cooling. Any excess of oxygen is either recycled to the burner or released to the open air after the removal of small portions of sulfur dioxide in the washer (6).
The following example illustrates the invention.
EXAMPLE
In a two component nozzle burner having a circular nozzle of a diameter of 2.5 mm for sulfur and a concentric ring nozzle for oxygen (inner diameter 7.5 mm, outer diameter 70 mm) 90 kg/h of liquid sulfur and 92 to 96 kg/h of oxygen were introduced (excess of oxygen varying from 3 to 7%). The burner was fixed at one end of a cylindrical steel tube (diameter 50 cm, length 3m) the tube being provided on the outside with a spiral condenser welded thereon for a water cooling and at the inside with a 3 mm asbestos coating (R Cerafelt).
The ignition of the flame was effected by means of a natural gas burner, the length of the flame being about 50 cm, the maximal flame temperature 1950C and the temperature of the wall of the combustion chamber ~inner side) 1400C. The end of the steel tube was connected to a second cooling segment ~length 3 m) being water-cooled as well. Thereafter the gas still had a temperature of 280C.
The gas contained from 0.13 to 1.87% by volume of S03, depending on the excess of oxygen.
.
. - -- . ., ...... . - - , :
~ ' ' ' ' .
1077~7~7 The flame may be produced by used burners which enable the sim-ultaneous introduction of liquid sulfur and oxygen such as two components nozzle burners as well as rotation burners. The proportion of liquid sulfur and oxygen is not cirtical. The process may be operated with stoichio-metrical quantities, with a slight excess of 2 (for example of up to 7%) or, if the sulfur dioxide formed is to be further oxidized to give SO3, with a higher excess of 2 of about 55%. In all cases the measured maximal temperaturesof the flame are at about 2000C.
The invention will now be illustrated by way of example using the accompanying drawing which depicts a flow scheme. The hot gases produced in the burner (1) are collected in a combustion chamber (2) having heat resistant walls. Chambers lined with highly fire-proof stones have proved particularly successful. The walls are advantageously cooled on the outside. Uncoated steel tubes which are cooled may also be used; the good heat tranfer, however, results in a rapid temperature decrease of the reaction gases and, consequently,in a possible residual content of unburnt sulfur. The thickness of the wall lining must be such that the inner wall temperature is at least 1200C, pre-ferably from 1400 to 1500C. In this case the temperature of the zone of in-candenscence formed at the wall is still so high that inspite of the outside cooling a sufficient quantity of sulfur is still burnt. Only in the case of small sulfur outputs i.e. in the case of sulfur outputs substantially smaller ; than those just obtainable in a given appratus the process may be operated from time to time without outside cooling owing to the backflow of the cooled flame gases. The combustion gas only contains a small quantity of SO3 (of about 0.1 to 1% by volume). A heat exchanger preferably consisting of a radiator and a convection part is connected after the reactor (3) in order to utilize the reaction heat. In order to control the temperature of the waste gas in the case of varying charges the cooling surfaces may be ad-vantageously subdivided. Cooling of the combustion gases to about 280 to ; ,~.
_ 5 _ ' ~ , ', : --.' ' .
,:
iO77~77 100C may be effected, for example, in an economizer (not illustrated in thedrawing). Thereby the feeding water of a steam producing boiler is heated at the pressure side of the pump. The combustion gas is then further cooled to about 40C in the following sulfuric acid washer (4). The small S03 content is simultaneously removed thereby. Pure S02 is precipitated in a liquid form in the condenser (5) by brine cooling. Any excess of oxygen is either recycled to the burner or released to the open air after the removal of small portions of sulfur dioxide in the washer (6).
The following example illustrates the invention.
EXAMPLE
In a two component nozzle burner having a circular nozzle of a diameter of 2.5 mm for sulfur and a concentric ring nozzle for oxygen (inner diameter 7.5 mm, outer diameter 70 mm) 90 kg/h of liquid sulfur and 92 to 96 kg/h of oxygen were introduced (excess of oxygen varying from 3 to 7%). The burner was fixed at one end of a cylindrical steel tube (diameter 50 cm, length 3m) the tube being provided on the outside with a spiral condenser welded thereon for a water cooling and at the inside with a 3 mm asbestos coating (R Cerafelt).
The ignition of the flame was effected by means of a natural gas burner, the length of the flame being about 50 cm, the maximal flame temperature 1950C and the temperature of the wall of the combustion chamber ~inner side) 1400C. The end of the steel tube was connected to a second cooling segment ~length 3 m) being water-cooled as well. Thereafter the gas still had a temperature of 280C.
The gas contained from 0.13 to 1.87% by volume of S03, depending on the excess of oxygen.
.
. - -- . ., ...... . - - , :
~ ' ' ' ' .
Claims (2)
- THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
l. A process for preparing sulfur dioxide from liquid sulfur and oxygen which comprises combining and burning technically pure oxygen containing at least 70% by volume O2 and finely dispersed liquid sulfur using a two component nozzle burner or a rotation burner without dilution by sulfur dioxide, the molar proportion of O2/S being about 1.0 to 1.55, collecting the hot gases in a combustion chamber having a heat resistant wall, the outer side of said wall being cooled and the inner side of said wall having a temperature of at least 1200°C and subsequently cooling the hot gases. - 2. Process as claimed in claim 1, which comprises operating at a pressure of 1 to 7 bars.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19742433231 DE2433231A1 (en) | 1974-07-11 | 1974-07-11 | PROCESS FOR THE PRODUCTION OF SULFUR DIOXYDE FROM SULFUR AND OXYGEN |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1077677A true CA1077677A (en) | 1980-05-20 |
Family
ID=5920231
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA231,243A Expired CA1077677A (en) | 1974-07-11 | 1975-07-10 | Process for preparing sulfur dioxide from sulfur and oxygen |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS5131698A (en) |
| BE (1) | BE831302A (en) |
| CA (1) | CA1077677A (en) |
| DE (1) | DE2433231A1 (en) |
| FR (1) | FR2277766A1 (en) |
| GB (1) | GB1514807A (en) |
| NL (1) | NL7508019A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT350157B (en) * | 1976-08-20 | 1979-05-10 | Herberts & Co Gmbh | AQUEOUS, PHENOLIC RESIN-FREE COATING AGENT AND PROCESS FOR ITS PRODUCTION |
| JPS54119391A (en) * | 1978-03-09 | 1979-09-17 | Hitachi Zosen Corp | Combustion waste heat recovering apparatus for sulfur dioxide manufacturing apparatus |
| EP0071078A1 (en) * | 1981-07-25 | 1983-02-09 | Bayer Ag | Process for producing sulfuric acid |
| JPS62278108A (en) * | 1986-05-27 | 1987-12-03 | シイ−アイ−エル・インコ−ポレイテツド | Sulfur combustion furnace and boiler composite device |
| AR039994A1 (en) * | 2002-11-06 | 2005-03-09 | Quimetal Ind S A | AUTOMATED PRODUCTION METHOD OF PURE SO2 FROM SULFUR AND OXYGEN |
-
1974
- 1974-07-11 DE DE19742433231 patent/DE2433231A1/en not_active Withdrawn
-
1975
- 1975-07-04 NL NL7508019A patent/NL7508019A/en unknown
- 1975-07-09 JP JP8363575A patent/JPS5131698A/en active Pending
- 1975-07-10 FR FR7521653A patent/FR2277766A1/en active Granted
- 1975-07-10 CA CA231,243A patent/CA1077677A/en not_active Expired
- 1975-07-11 GB GB2924275A patent/GB1514807A/en not_active Expired
- 1975-07-11 BE BE158240A patent/BE831302A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2277766B1 (en) | 1981-09-18 |
| NL7508019A (en) | 1976-01-13 |
| GB1514807A (en) | 1978-06-21 |
| DE2433231A1 (en) | 1976-01-29 |
| JPS5131698A (en) | 1976-03-17 |
| BE831302A (en) | 1976-01-12 |
| FR2277766A1 (en) | 1976-02-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |