CA1081134A - Method for operating a desulfurizing reactor for stack gases - Google Patents
Method for operating a desulfurizing reactor for stack gasesInfo
- Publication number
- CA1081134A CA1081134A CA264,953A CA264953A CA1081134A CA 1081134 A CA1081134 A CA 1081134A CA 264953 A CA264953 A CA 264953A CA 1081134 A CA1081134 A CA 1081134A
- Authority
- CA
- Canada
- Prior art keywords
- reactor
- conduit
- inlet
- gas
- outlet
- 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
-
- 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
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
- B01D53/508—Sulfur oxides by treating the gases with solids
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Environmental & Geological Engineering (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Treating Waste Gases (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A reactor system for desulfurizing stack gas by means of activated carbon has a reactor through which the activated carbon and stack gases are normally circulated.
When the system is shut down the inlet and outlet conduits for the reactor are disconnected from the source of gas to be desulfurized and from the chimney of the installation and are connected together in a closed path through a cooler.
A blower in this path serves to continuously recirculate the gases in the path while cooling them. At the same time an inert gas having less than 15% by volume of oxygen is fed into this path in order to maintain it under superatmospheric pressure.
A reactor system for desulfurizing stack gas by means of activated carbon has a reactor through which the activated carbon and stack gases are normally circulated.
When the system is shut down the inlet and outlet conduits for the reactor are disconnected from the source of gas to be desulfurized and from the chimney of the installation and are connected together in a closed path through a cooler.
A blower in this path serves to continuously recirculate the gases in the path while cooling them. At the same time an inert gas having less than 15% by volume of oxygen is fed into this path in order to maintain it under superatmospheric pressure.
Description
~)81134 1 The invention relates to the operation of a reactor through which flows a coal-containing adsorption agent for the desulfurizing of stack gases.
Normally in such a process the stack gas is conducted through a travelling layer reactor which displaces the adsorption agent slowly downwardly and wherein the stack gas flows concurrently with or countercurrent to the adsorption agent. The sulfur oxide adsorbed into the adsorption agent is oxidized to sulfuric acid, resulting as a result of the adsorption and reaction heat in a rise in temperature of the adsorption agent. Since during operation the adsorption agent is traversed by the stack gases to be desulfurized, the corresponding heat is conducted off so that the increase in the temperature lies within certain limits and is established without outside interference to approximately 80 - 160 C. ~ -If the operation is shut down for a few hours to a few days air is sucked into the reactor by the suction of the stack which is not provided with a closure. The result of this is that `~
the carbon-containing adsorption agent is heated even more by reaction between the oxygen in the air and the adsorption agent.
Since during nonuse of the apparatus none of the reaction heat is drawn off, it is possible for hot spots to develop in the adsorption-agent layer. Such hot spots lead, in particular during starting-up of a recently down reactor, to considerable combustion of the adsorption material if not to a complete burning-up of the charge.
It is an object of the present invention to eliminate ; this danger and to enable with simple means the interruption of operation at any time of such a desulfurizing installation.
In accordance with this invention this danger is overcome in that the stack gas in the reactor system is conducted through a cooler and an inert gas is injected into this reactor at
Normally in such a process the stack gas is conducted through a travelling layer reactor which displaces the adsorption agent slowly downwardly and wherein the stack gas flows concurrently with or countercurrent to the adsorption agent. The sulfur oxide adsorbed into the adsorption agent is oxidized to sulfuric acid, resulting as a result of the adsorption and reaction heat in a rise in temperature of the adsorption agent. Since during operation the adsorption agent is traversed by the stack gases to be desulfurized, the corresponding heat is conducted off so that the increase in the temperature lies within certain limits and is established without outside interference to approximately 80 - 160 C. ~ -If the operation is shut down for a few hours to a few days air is sucked into the reactor by the suction of the stack which is not provided with a closure. The result of this is that `~
the carbon-containing adsorption agent is heated even more by reaction between the oxygen in the air and the adsorption agent.
Since during nonuse of the apparatus none of the reaction heat is drawn off, it is possible for hot spots to develop in the adsorption-agent layer. Such hot spots lead, in particular during starting-up of a recently down reactor, to considerable combustion of the adsorption material if not to a complete burning-up of the charge.
It is an object of the present invention to eliminate ; this danger and to enable with simple means the interruption of operation at any time of such a desulfurizing installation.
In accordance with this invention this danger is overcome in that the stack gas in the reactor system is conducted through a cooler and an inert gas is injected into this reactor at
-2-- : : . : . ' - :
13~
1 least under a~mosyh~ric pr~ssure.
According to thc invention thc reactor system hac. in additioll to the reactor itself those conduits which lcad to the shuttoff valves ancl whi.ch separ~te the reactor from the power plan~
on one side and from the chi.mney on the other side. Since such shutoff valves do not seal perfectly -- the conduits having a dia-meter of more than 1 meter, e.y. ~ meters -- it is impossible tO
prevent a continuous suction ef~ect from the chimney on the reactor syste~.. This suction effect has, as described above, the effect o' pulling air into the reactor and thus into the hot adsorption agent so that it can result in the production in the adsorption agent of the described hot spots.
Specifically, a reactor system for connec~ion to a source of an adsorption agent and a source of gas to be purified, may in-clude a reactor; an inlet conduit connected between the source of gas and the reactor; an outlet conduit connected to the reac~or;
respective inlet and outlet valves in the inlet and outlet con-duits movable between an open position permitting gas flow through the respective conduit; and means in one of the conduits for feed-ing gas from the inlet conduit into the reactor and discharging gas from the reactor into the outlet conduit.
.Further, a connection conduit may be connected between the inlet and outlet conduits at locations thereon between the re-spective valves and the reactor. Valve mea~s are located in the connection conduit movable between an open position permitting g-as ..
flow through the connection conduit between the inlet and outlet conduits and a closed position blocking flow between the inlet and outlet conduits through the connection conduit, means are provided in the connection conduit for coolin~ gas passing theretllrough ~30 between the in].et and outlet conduits, and additional means are ~3~.
. '~' .
108~134 provided for injecting an inert g;lS int:o one of the conduits for maintaining the connection conduit with its valve means in the closed position, and the inlet and outlet conduits between the re-spective valves in the closed positions, and the reactor, under superatmospheric pressure.
The recirculation of the stack gases in the reactor system is ef~ected by providing the aforementioned conduit connection ~,e-tween the sides of the shutoff valv~s turned toward the reactor, this connection extending through the cooler so as to connect the conduits leading from the shutoff valves to the reactor directly with each other. In case the system is shut down these shutoff valves are closed and the gases contained in the reactor and in the conduits at the moment of closing of the valves is circulated by means of the continuously operated blower. The cooling of the gases in the mentioned connection conduit and their flushing of the adsorption agent will prevent the formation of the undesirable hot spots.
Since, as mentioned, the entry of air into this system cannot be avoided at the same time during a succession of operations a~gas which is inert relative to the carbon-containing adsorption agent is fed into the sys-tem. This inert gas can, for ex~mple, be a combustion gas from a fuel-oil fired burner or can be ~he stack gas itself. Such gases should not be too hot when fed ~ .
' . . , :: , . .: :
.
1~81~.34 1 into the system so that the coolQr is not overloaded. For this reason it is most desirable to feed into the reactor system the coldest possible inert gas.
The pressure produced in the reaction system by the injection thereinto of the inert gases should at least be equal to atmospheric pressure. Substantially higher pressures have the result of causing unnecessary losses by leakage of the gas out of the system through unsealed locations.
Pure nitrogen can only be used in some cases as the inert gas. For the arrangement according to this invention it is therefore of considerable importance that gases are used as inert gases which contain less than a predetermined quantity of 2 It has surprisingly been shown that a 2 content of up to 15% by volume can be employed in order to obtain an effective cooling of the adsorption agent. In any case the gas leaving the cooler should be cooled by at least 10C, preferably 20 - 50C.
As a result of the reaction between SO2 and 2 on one side and the carbon-contàining adsorption agent on the other side the recirculating gas contains less and less of these con-stituents so that exothermic reactions are not supported and the cooling effect of the recirculating gas is continuously more effective. As a result of this it is possible to cool the re-circulating gas less and/or circulate it more slowly. The cooling effect of the gas as well as the volume per unit time of the gas circulating in the closed cooling path can be regulated by a temperature sensor installed in the reactor system on the blower and/or on the cooler.
The invention allows a danger-free shutting-down of the reactor without exces~s cooling of its adsorption agent so that when started up again the system is immediately effective. On the 1~81134 1 other hand, for example during long shutdowns, the invention allows a danger-free cooling of the adsorption agent down to around 80 C whereupon the input of inert gas can be stopped and the blower and cooler can be shut down.
The process according to the invention is described more closely with reference to the accompanying drawing:
The stack gases drawn from a coal-burning installation, e.g. a power plant l, pass through a conduit 2, an open shut-off valve 3, as well as through conduit 4 into the reactor 5. The reactor is continuously fed from above through a gate 6 with acti-vated carbon which is drawn off simultaneously through the gate 7.
The stack gas is drawn out of the reactor through a conduit 8 by a blower 9 and is fed via a conduit 10, an open valve ll, and a conduit 12 to a stack 130 The conduits 4 and lO are connected together by connection conduits 14 which lead through the two (closed) valves 15 and 16 to the cooler 17.
Into the conduit 8 there opens a conduit 18 with a (closed) valve 19 through which inert gas is injected into the system. During operation of the system the valves 3 and ll are open and the valves 15, 16 and 19 are closed.
When there is no stack gas fed into the conduit 2 the valves 3 and 11 are closed and the valves l9, 15, and 16 are open.
Simultaneously the gates 6 and 7 are arrested and the cooler 17 is started up~ The stack gas as well as the additional inert gas in-jected into the system, by means of which the pressure in the system is lifted to for example 1.1 atm, flow now in a closed path between the reactor 5 and the cooler 17 so that the temperature in the adsorption agent is constant without the formation of hot spots, or slightly lowered, or dropped down to ambient temperature.
't ~ ~5~
, . - -- .
1~)81i34 1 In case of disturbances at the gates 6 and 7 or in other locations in the reactor 5 in order to cool the activated carbon only the valve 11 is closed, the valves 15 and 16 opened, and the cooler 17 operated. Thus, the stack gas, having for instance 5 - 10~ by volume 2' enters the system as an inert gas over the open valve 3 so that in this situation also a danger-free and rapid cooling of the activated carbon is achieved.
:
", , .
.
13~
1 least under a~mosyh~ric pr~ssure.
According to thc invention thc reactor system hac. in additioll to the reactor itself those conduits which lcad to the shuttoff valves ancl whi.ch separ~te the reactor from the power plan~
on one side and from the chi.mney on the other side. Since such shutoff valves do not seal perfectly -- the conduits having a dia-meter of more than 1 meter, e.y. ~ meters -- it is impossible tO
prevent a continuous suction ef~ect from the chimney on the reactor syste~.. This suction effect has, as described above, the effect o' pulling air into the reactor and thus into the hot adsorption agent so that it can result in the production in the adsorption agent of the described hot spots.
Specifically, a reactor system for connec~ion to a source of an adsorption agent and a source of gas to be purified, may in-clude a reactor; an inlet conduit connected between the source of gas and the reactor; an outlet conduit connected to the reac~or;
respective inlet and outlet valves in the inlet and outlet con-duits movable between an open position permitting gas flow through the respective conduit; and means in one of the conduits for feed-ing gas from the inlet conduit into the reactor and discharging gas from the reactor into the outlet conduit.
.Further, a connection conduit may be connected between the inlet and outlet conduits at locations thereon between the re-spective valves and the reactor. Valve mea~s are located in the connection conduit movable between an open position permitting g-as ..
flow through the connection conduit between the inlet and outlet conduits and a closed position blocking flow between the inlet and outlet conduits through the connection conduit, means are provided in the connection conduit for coolin~ gas passing theretllrough ~30 between the in].et and outlet conduits, and additional means are ~3~.
. '~' .
108~134 provided for injecting an inert g;lS int:o one of the conduits for maintaining the connection conduit with its valve means in the closed position, and the inlet and outlet conduits between the re-spective valves in the closed positions, and the reactor, under superatmospheric pressure.
The recirculation of the stack gases in the reactor system is ef~ected by providing the aforementioned conduit connection ~,e-tween the sides of the shutoff valv~s turned toward the reactor, this connection extending through the cooler so as to connect the conduits leading from the shutoff valves to the reactor directly with each other. In case the system is shut down these shutoff valves are closed and the gases contained in the reactor and in the conduits at the moment of closing of the valves is circulated by means of the continuously operated blower. The cooling of the gases in the mentioned connection conduit and their flushing of the adsorption agent will prevent the formation of the undesirable hot spots.
Since, as mentioned, the entry of air into this system cannot be avoided at the same time during a succession of operations a~gas which is inert relative to the carbon-containing adsorption agent is fed into the sys-tem. This inert gas can, for ex~mple, be a combustion gas from a fuel-oil fired burner or can be ~he stack gas itself. Such gases should not be too hot when fed ~ .
' . . , :: , . .: :
.
1~81~.34 1 into the system so that the coolQr is not overloaded. For this reason it is most desirable to feed into the reactor system the coldest possible inert gas.
The pressure produced in the reaction system by the injection thereinto of the inert gases should at least be equal to atmospheric pressure. Substantially higher pressures have the result of causing unnecessary losses by leakage of the gas out of the system through unsealed locations.
Pure nitrogen can only be used in some cases as the inert gas. For the arrangement according to this invention it is therefore of considerable importance that gases are used as inert gases which contain less than a predetermined quantity of 2 It has surprisingly been shown that a 2 content of up to 15% by volume can be employed in order to obtain an effective cooling of the adsorption agent. In any case the gas leaving the cooler should be cooled by at least 10C, preferably 20 - 50C.
As a result of the reaction between SO2 and 2 on one side and the carbon-contàining adsorption agent on the other side the recirculating gas contains less and less of these con-stituents so that exothermic reactions are not supported and the cooling effect of the recirculating gas is continuously more effective. As a result of this it is possible to cool the re-circulating gas less and/or circulate it more slowly. The cooling effect of the gas as well as the volume per unit time of the gas circulating in the closed cooling path can be regulated by a temperature sensor installed in the reactor system on the blower and/or on the cooler.
The invention allows a danger-free shutting-down of the reactor without exces~s cooling of its adsorption agent so that when started up again the system is immediately effective. On the 1~81134 1 other hand, for example during long shutdowns, the invention allows a danger-free cooling of the adsorption agent down to around 80 C whereupon the input of inert gas can be stopped and the blower and cooler can be shut down.
The process according to the invention is described more closely with reference to the accompanying drawing:
The stack gases drawn from a coal-burning installation, e.g. a power plant l, pass through a conduit 2, an open shut-off valve 3, as well as through conduit 4 into the reactor 5. The reactor is continuously fed from above through a gate 6 with acti-vated carbon which is drawn off simultaneously through the gate 7.
The stack gas is drawn out of the reactor through a conduit 8 by a blower 9 and is fed via a conduit 10, an open valve ll, and a conduit 12 to a stack 130 The conduits 4 and lO are connected together by connection conduits 14 which lead through the two (closed) valves 15 and 16 to the cooler 17.
Into the conduit 8 there opens a conduit 18 with a (closed) valve 19 through which inert gas is injected into the system. During operation of the system the valves 3 and ll are open and the valves 15, 16 and 19 are closed.
When there is no stack gas fed into the conduit 2 the valves 3 and 11 are closed and the valves l9, 15, and 16 are open.
Simultaneously the gates 6 and 7 are arrested and the cooler 17 is started up~ The stack gas as well as the additional inert gas in-jected into the system, by means of which the pressure in the system is lifted to for example 1.1 atm, flow now in a closed path between the reactor 5 and the cooler 17 so that the temperature in the adsorption agent is constant without the formation of hot spots, or slightly lowered, or dropped down to ambient temperature.
't ~ ~5~
, . - -- .
1~)81i34 1 In case of disturbances at the gates 6 and 7 or in other locations in the reactor 5 in order to cool the activated carbon only the valve 11 is closed, the valves 15 and 16 opened, and the cooler 17 operated. Thus, the stack gas, having for instance 5 - 10~ by volume 2' enters the system as an inert gas over the open valve 3 so that in this situation also a danger-free and rapid cooling of the activated carbon is achieved.
:
", , .
.
Claims (3)
1. A reactor system for connection to a source of an absorption agent and a source of gas to be purified, said system comprising: a reactor; an inlet conduit connected between said source of gas and said reactor; an outlet conduit connected to said reactor; respective inlet and outlet valves in said inlet and outlet conduits movable between an open position permitting gas flow through the respective conduit and a closed position blocking gas flow through the respective conduit; means in one of said con-duits for feeding gas from said inlet conduit into said reactor and discharging gas from said reactor into said outlet conduit; a connection conduit connected between said inlet and outlet conduits at locations theron between the respective valves and said reactor;
valve means in said connection conduit movable between an open posi-tion permitting gas flow through said connection conduit between said inlet and outlet conduits and a closed position blocking flow between said inlet and outlet conduits through said connection con-duit; means in said connection conduit for cooling gas passing therethrough between said inlet and outlet conduits; and means for injecting an inert gas into one of said conduits for maintaining said reactor, said connection conduit with its said valve means in said closed position, and said inlet and outlet conduits between the respective valves in said closed positions and said reactor under superatmospheric pressure.
valve means in said connection conduit movable between an open posi-tion permitting gas flow through said connection conduit between said inlet and outlet conduits and a closed position blocking flow between said inlet and outlet conduits through said connection con-duit; means in said connection conduit for cooling gas passing therethrough between said inlet and outlet conduits; and means for injecting an inert gas into one of said conduits for maintaining said reactor, said connection conduit with its said valve means in said closed position, and said inlet and outlet conduits between the respective valves in said closed positions and said reactor under superatmospheric pressure.
2. The system defined in claim 1, further comprising means for circulating said agent through said reactor when said inlet and outlet valves are in said open position and said valve means in said connection conduit is in said closed position.
3. The system defined in claim 1, wherein said means for feeding is a blower in said outlet conduit between said outlet valve and said reactor.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19752550190 DE2550190C2 (en) | 1975-11-07 | 1975-11-07 | Process for the desulphurization of flue gases |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1081134A true CA1081134A (en) | 1980-07-08 |
Family
ID=5961243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA264,953A Expired CA1081134A (en) | 1975-11-07 | 1976-11-05 | Method for operating a desulfurizing reactor for stack gases |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5938009B2 (en) |
| CA (1) | CA1081134A (en) |
| DE (1) | DE2550190C2 (en) |
| FR (1) | FR2330434A1 (en) |
| GB (1) | GB1536506A (en) |
| IT (1) | IT1066793B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2911712C2 (en) * | 1979-03-24 | 1991-10-31 | Bergwerksverband Gmbh, 4300 Essen | Process for removing sulfur oxides and nitrogen oxides from exhaust gases |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1347731A (en) * | 1970-12-10 | 1974-02-27 | Sumitomo Heavy Industries | Continuous moving layer type adsorption device |
| JPS512312B2 (en) * | 1972-03-21 | 1976-01-24 | ||
| JPS5137632B2 (en) * | 1972-03-21 | 1976-10-16 | ||
| DE2509470C3 (en) * | 1975-03-05 | 1980-04-10 | Bergwerksverband Gmbh, 4300 Essen | Process for removing sulfur oxide components from combustion exhaust gases |
-
1975
- 1975-11-07 DE DE19752550190 patent/DE2550190C2/en not_active Expired
-
1976
- 1976-11-05 FR FR7633419A patent/FR2330434A1/en not_active Withdrawn
- 1976-11-05 IT IT5206676A patent/IT1066793B/en active
- 1976-11-05 CA CA264,953A patent/CA1081134A/en not_active Expired
- 1976-11-08 JP JP51133292A patent/JPS5938009B2/en not_active Expired
- 1976-11-08 GB GB4635776A patent/GB1536506A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2330434A1 (en) | 1977-06-03 |
| DE2550190C2 (en) | 1983-10-27 |
| GB1536506A (en) | 1978-12-20 |
| JPS5282675A (en) | 1977-07-11 |
| IT1066793B (en) | 1985-03-12 |
| JPS5938009B2 (en) | 1984-09-13 |
| DE2550190A1 (en) | 1977-05-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |