GB1574162A - Removal of sulphur compounds from synthesis gas - Google Patents

Removal of sulphur compounds from synthesis gas Download PDF

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Publication number
GB1574162A
GB1574162A GB4658777A GB4658777A GB1574162A GB 1574162 A GB1574162 A GB 1574162A GB 4658777 A GB4658777 A GB 4658777A GB 4658777 A GB4658777 A GB 4658777A GB 1574162 A GB1574162 A GB 1574162A
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United Kingdom
Prior art keywords
reactor
gasification
coal
slag
sulphur
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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
Application number
GB4658777A
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Dr C Otto and Co GmbH
Saarbergwerke AG
Original Assignee
Dr C Otto and Co GmbH
Saarbergwerke AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
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Publication of GB1574162A publication Critical patent/GB1574162A/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1493—Selection of liquid materials for use as absorbents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1456—Removing acid components
    • B01D53/1468—Removing hydrogen sulfide
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/57—Gasification using molten salts or metals
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/72—Other features
    • C10J3/82—Gas withdrawal means
    • C10J3/84—Gas withdrawal means with means for removing dust or tar from the gas
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00—Details of gasification processes
    • C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0913—Carbonaceous raw material
    • C10J2300/093—Coal
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00—Details of gasification processes
    • C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0953—Gasifying agents
    • C10J2300/0959—Oxygen
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00—Details of gasification processes
    • C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0953—Gasifying agents
    • C10J2300/0973—Water
    • C10J2300/0976—Water as steam
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00—Details of gasification processes
    • C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0983—Additives
    • C10J2300/0996—Calcium-containing inorganic materials, e.g. lime

Description

(54) IMPROVEMENTS IN OR RELATING TO THE REMOVAL OF SULPHUR COMPOUNDS FROM SYNTHESIS GAS (71) We, SAARBERGWERKE AKTIEN GESELLscHAFT, a German Company of Trierer Strasse 1, 6600 Saarbriicken, German Federal Republic, and DR. C. OTTO & COM PANY GBSELLSCEIAFT MIT BESCHRANKTER HAFTUNG, a German Company of 4630 Bochum, German Federal Republic, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a method for removing sulphur compounds, in particular H2S, from synthesis gas produced by gasification of coal or other carboniferous solids in a gasification reactor at high temperature by reaction with inorganic absorption agents.
Synthesis gas produced by the gasification of coal using water vapour and oxygen or air, normally contains sulphur components which, during or subsequent to the utilisation of the gas in a consuming device, may cause corrosion damage to the component parts of the device, or may lead to environmental pollution if the gaseous effluent is released into the atmosphere without being cleansed.
A method for removing sulphur from crude gases leaving fuel gasifiers is described in German Patent Specification No.
1,444,961, as open to inspection. In this method, a hot crude gas at about 1000or produced in a gasification chamber is mixed in a subsequent separate reaction chamber with powdered lime as an absorption agent which reacts with the sulphur compounds in the crude gas and is separated from the residual gas in a subsequent cyclone separator.
It is a disadvantage of this known method that a considerable technical effort is needed and that the degree of sulphur extraction is not particularly high. A separate gasification chamber and a separate special reaction chamber are needed to enable the sulphur extraction step to be carried out. Since the exchange of material from the gas to the absorbent takes place in a process stage downstream of the reactor, the surface available for the removal of the sulphur is small and consequently the degree of sulphur extraction is low.
It is an object of the present invention to provide a method of removing sulphur compounds from synthesis gas by means of which a very high proportion of sulphur can be removed from the synthesis gas in a reliable manner and with only a small technical outlay.
According to the invention, there is provided a method of removing sulphur compounds from synthesis gas produced by the gasification of coal or other carboniferous solid in a gasification reactor at elevated temperature, comprising the step of effecting material exchange between said synthesis gas and an inorganic absorption agent for said sulphur compounds which is predominantly present in the molten phase immediately above the peripheral region of a slag bath provided in the bottom part of said gasification reactor.
An important advantage of the method of the invention is that the absorption agent can remove sulphur compounds from the gas better in the molten phase than in the solid phase, since the material exchange proceeds more quickly and with a greater intensity in the molten phase, and a further advantage is that the efficiency of sulphur extraction is particularly high when the reaction between the sulphur compounds and the molten absorption agent takes place immediately above and in the peripherl region of a liquid slag bath provided in the lower part of the gasification reactor since, because of the highly turbulent flow conditions prevailing in this region, there is particularly intense swirling and therefore mixing, between droplets of the molten absorption agent and the synthesis gas containing the sulphur compounds.
It has been found to be particularly advantageous if the absorption agent is fed into the gasification reactor, together with the coal or other carboniferous solid to be gasified for example, by means of a compressed propellant gas, and the removal of the sulphur compounds by the absorption agent is effected directly in the gasification reactor, so that the exothermic heat of the gasification reactions can be directly utilised to liquefy the absorption agent.
Should the gasification reactions be carried out at temperatures above the melting point of the slag formed, a further advantage is obtained in that the liquid absorption agent now charged with the sulphur compounds can be withdrawn from the gasification reactor easily in the molten phase.
Advantageously, a calcium compound, preferably calcium oxide (CaO) or calcium carbonate (CaCO3), is used as the absorption agent which, at the temperatures prevailing in the reactor, combines with the components of the coal ash to form liquid compounds which bring about the material exchange at controlled basicity. In addition, lime is readily available and economical to use.
Alkali metal compounds, for example, Na2O, Na3CO3, K2O, and K2CO3, are equally advantageous for use as absorption agents as calcium compounds. These alkali metal compounds also have a marked affinity for sulphur, so that a particularly high degree of sulphur extraction can be expected. In addition, mixtures of the various absorption agents may be added.
Advantages are also obtained by regulating the viscosity of the resultant slag by the use of further additives, so that it is neither too thin and foams, nor so thick that it can no longer be drawn off. Examples of such additives are iron oxides and/or quartz sand.
The invention will now be further described with reference to the drawing, which is a schematic side viwe of part of a coalgasification plant to illustrate a specific em bodiment of the invention.
Referring to the drawing, a gasification reactor 1 is provided in its lower part 2 with lance-like inlets 3 which project into the reactor and serve for blowing in coal or other carboniferous dust together with the necessary gasification agents (e.g. water vapour and oxygen) and an inorganic absorbent. The inlets 3 are arranged to be angled slightly downwards so that the gases and the carboniferous dust introduced form a highly turbulent multi-phase circulating stream immediately above the periphery of a slag bath 4 accumulating in the bottom part of the reactor chamber. The slag itself is drawn off into a water bath 5, arranged below the reactor 1, when the surface of the liquid slag rises above a predetermined level.
The reaction of the coal dust with the water vapour and oxygen takes place in particular in the hot zone just above the slag bath 4.
The synthesis gas formed leaves the gasification reactor through an outlet 6 at the upper end thereof and is fed to a cyclone separator 7 which it leaves in a dust-free state through an outlet pipe 8.
The gasification plant operates as follows: The gasification agents in the form of water vapour and oxygen, together with the carboniferous dust, such as coal dust from pit coal, to which an incombustible finepowdered mineral absorbent is added, are blown into the lower part 2 of the reactor 1 through the lance-like inlets 3. The gas pressure in the inlets 3 must be much greater than the pressure inside the reactor 1, for example 25-30 bars greater.
The carboniferous dust blown into the lower part 2 of the reactor reacts with the gasification agents as the temperature is raised to 1500 to 2200"C above the slag bath provided in the bottom of the gasification reactor. Depending on the sort of coal used, synthesis gas is formed having an approximate composition by volume of: 55% CO, 33% H2, 0.5% sulphur com pounds, in particular H2S, together with CO2 and H2O.
The powdered inorganic additive blown in with the coal dust, for instance calcium oxide (CaO), comes into intense contact with the reaction gases the speed of which can be as high as 100 m/sec in the highly turbulent multiphase circulating stream prevailing in this zone. The calcium oxide dust4 which forms liquid compounds with ash components from the coal, particularly with silicon dioxide, aluminium oxide, and/or the iron oxides present in the peripheral region of the slag bath 4, reacts with the sulphur compounds contained in the synthesis gas to bind the sulphur.
Instead of calcium compounds, alkali metal carbonates, such as soda (Na2CO,) or potash (K2CO2), for instance, can be used. Both substances have a relatively low melting point and a high affinity for sulphur.
The slag forming during the gasification of coal usually contains inter alia silicon, aluminium and iron compounds. Through the controlled admixture of further inorganic additives such as FeO, Foe203 and SiO2, for example, to the coat dust, the viscosity of the slag can be controlled in such a way that it does not become too thick to flow awav satisfactorily, or so thin that it foams or that too many slag particles are carried out with the stream of gas. In addition, a favourable basicity level for the slag formation and sulphur extraction can be set in this way.
WHAT WE CLAIM IS: 1. A method of removing sulphur com
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. into the gasification reactor, together with the coal or other carboniferous solid to be gasified for example, by means of a compressed propellant gas, and the removal of the sulphur compounds by the absorption agent is effected directly in the gasification reactor, so that the exothermic heat of the gasification reactions can be directly utilised to liquefy the absorption agent. Should the gasification reactions be carried out at temperatures above the melting point of the slag formed, a further advantage is obtained in that the liquid absorption agent now charged with the sulphur compounds can be withdrawn from the gasification reactor easily in the molten phase. Advantageously, a calcium compound, preferably calcium oxide (CaO) or calcium carbonate (CaCO3), is used as the absorption agent which, at the temperatures prevailing in the reactor, combines with the components of the coal ash to form liquid compounds which bring about the material exchange at controlled basicity. In addition, lime is readily available and economical to use. Alkali metal compounds, for example, Na2O, Na3CO3, K2O, and K2CO3, are equally advantageous for use as absorption agents as calcium compounds. These alkali metal compounds also have a marked affinity for sulphur, so that a particularly high degree of sulphur extraction can be expected. In addition, mixtures of the various absorption agents may be added. Advantages are also obtained by regulating the viscosity of the resultant slag by the use of further additives, so that it is neither too thin and foams, nor so thick that it can no longer be drawn off. Examples of such additives are iron oxides and/or quartz sand. The invention will now be further described with reference to the drawing, which is a schematic side viwe of part of a coalgasification plant to illustrate a specific em bodiment of the invention. Referring to the drawing, a gasification reactor 1 is provided in its lower part 2 with lance-like inlets 3 which project into the reactor and serve for blowing in coal or other carboniferous dust together with the necessary gasification agents (e.g. water vapour and oxygen) and an inorganic absorbent. The inlets 3 are arranged to be angled slightly downwards so that the gases and the carboniferous dust introduced form a highly turbulent multi-phase circulating stream immediately above the periphery of a slag bath 4 accumulating in the bottom part of the reactor chamber. The slag itself is drawn off into a water bath 5, arranged below the reactor 1, when the surface of the liquid slag rises above a predetermined level. The reaction of the coal dust with the water vapour and oxygen takes place in particular in the hot zone just above the slag bath 4. The synthesis gas formed leaves the gasification reactor through an outlet 6 at the upper end thereof and is fed to a cyclone separator 7 which it leaves in a dust-free state through an outlet pipe 8. The gasification plant operates as follows: The gasification agents in the form of water vapour and oxygen, together with the carboniferous dust, such as coal dust from pit coal, to which an incombustible finepowdered mineral absorbent is added, are blown into the lower part 2 of the reactor 1 through the lance-like inlets 3. The gas pressure in the inlets 3 must be much greater than the pressure inside the reactor 1, for example 25-30 bars greater. The carboniferous dust blown into the lower part 2 of the reactor reacts with the gasification agents as the temperature is raised to 1500 to 2200"C above the slag bath provided in the bottom of the gasification reactor. Depending on the sort of coal used, synthesis gas is formed having an approximate composition by volume of: 55% CO, 33% H2, 0.5% sulphur com pounds, in particular H2S, together with CO2 and H2O. The powdered inorganic additive blown in with the coal dust, for instance calcium oxide (CaO), comes into intense contact with the reaction gases the speed of which can be as high as 100 m/sec in the highly turbulent multiphase circulating stream prevailing in this zone. The calcium oxide dust4 which forms liquid compounds with ash components from the coal, particularly with silicon dioxide, aluminium oxide, and/or the iron oxides present in the peripheral region of the slag bath 4, reacts with the sulphur compounds contained in the synthesis gas to bind the sulphur. Instead of calcium compounds, alkali metal carbonates, such as soda (Na2CO,) or potash (K2CO2), for instance, can be used. Both substances have a relatively low melting point and a high affinity for sulphur. The slag forming during the gasification of coal usually contains inter alia silicon, aluminium and iron compounds. Through the controlled admixture of further inorganic additives such as FeO, Foe203 and SiO2, for example, to the coat dust, the viscosity of the slag can be controlled in such a way that it does not become too thick to flow awav satisfactorily, or so thin that it foams or that too many slag particles are carried out with the stream of gas. In addition, a favourable basicity level for the slag formation and sulphur extraction can be set in this way. WHAT WE CLAIM IS:
1. A method of removing sulphur com
pounds from synthesis gas produced by the gasification of coal or other carboniferous solid in a gasification reactor at elevated temperature, comprising the step of effecting material exchange between said synthesis gas and an inorganic absorption agent for said sulphur compounds which is predominantly present in the molten phase immediately above the peripheral region of a slag bath provided in the bottom part of said gasification reactor.
2. A method as claimed in Claim 1, wherein said material exchange is effected in said reactor, said molten phase being formed from an absorption agent fed into said reactor in solid form and converted therein to a molten phase by the exothermic heat produced by the gasification reactor.
3. A method as claimed in Claim 1 or Claim 2, wherein said absorption agent is or includes a calcium compound which forms a compound or compounds with one or more components of the slag which is molten at the temperature prevailing within the reactor.
4. A method as claimed in Claim 3, wherein said calcium compound is calcium oxide (CaO), or calcium carbonate (CaCO3).
5. A method as claimed in any one of the preceding Claims, wherein said absorption agent is or includes an alkali metal carbonate.
6. A method as claimed in Claim 5, wherein said alkali metal carbonate is soda (Na2COa), or potash (K2CO3).
7. A method as claimed in any one of the preceding Claims, wherein powdered coal or other carboniferous solid and a solid absorption agent are blown into the reactor by means of a compressed propellant gas.
8. A method as claimed in any one of the preceding Claims, wherein said coal or other carboniferous solid in powder form slag particles and said solid absorption agent are brought into a highly turbulent multiphase circulating stream within said reactor.
9. A method as claimed in any one of the preceding Claims, wherein further additives are introduced to control the viscosity of the slag formed in the reactor.
10. A method of removing sulphur compounds from synthesis gas produced by the gasification of coal or other carboniferous solid, substantially as hereinbefore described with reference to the drawing.
11. Synthesis gas produced by the gasification of coal or other carboniferous solid and freed from sulphur compounds, by a method as claimed in any one of Claims 1 to 10.
GB4658777A 1976-11-10 1977-11-09 Removal of sulphur compounds from synthesis gas Expired GB1574162A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19762651177 DE2651177A1 (en) 1976-11-10 1976-11-10 PROCESS FOR REMOVING SULFUR COMPOUNDS, IN PARTICULAR H DEEP 2 S, FROM A SYNTHESIS GAS

Publications (1)

Publication Number Publication Date
GB1574162A true GB1574162A (en) 1980-09-03

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GB4658777A Expired GB1574162A (en) 1976-11-10 1977-11-09 Removal of sulphur compounds from synthesis gas

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JP (1) JPS5386703A (en)
DE (1) DE2651177A1 (en)
FR (1) FR2370785A1 (en)
GB (1) GB1574162A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4423702A (en) * 1982-01-22 1984-01-03 Ashworth Robert A Method for desulfurization, denitrifaction, and oxidation of carbonaceous fuels
EP0490202B1 (en) * 1990-12-14 1993-07-14 MAN Gutehoffnungshütte Aktiengesellschaft Activated carbon filter for separating noxious gases, such as dioxins and furans, from flue gases before entering the chimney
EP2537615B1 (en) * 2011-06-21 2014-11-26 Klingelnberg AG Robust method for skiving

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1189247A (en) * 1957-11-12 1959-10-01 Texaco Development Corp Process for the production of carbon monoxide practically free from sulfur gases
US3533739A (en) * 1968-04-01 1970-10-13 Black Sivalls & Bryson Inc Combustion of sulfur-bearing carbonaceous fuel
US3567377A (en) * 1968-08-12 1971-03-02 Pullman Inc Recovery of sulfur values from sulfur-bearing materials
US3916617A (en) * 1974-03-29 1975-11-04 Rockwell International Corp Process for production of low BTU gas

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Publication number Publication date
DE2651177A1 (en) 1978-05-18
JPS5386703A (en) 1978-07-31
FR2370785A1 (en) 1978-06-09

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