Exhaust gas treatment system
A reduction device, an acid gas recovery device, a recovery device collector, and a first removed substance returning line are provided. The reduction device is configured to perform a reduction process to turn iron oxide to reduced iron by adding a reducing agent. The acid gas recovery device is configured to recover CO 2 being acid gas with CO 2 absorbing liquid being acid gas absorbing liquid from exhaust gas containing at least powder-shaped iron-based solid substances and the acid gas, which are discharged from the reduction device. The recovery device collector is configured to collect the iron-based solid substance contained in the absorbing liquid with a filter. The iron-based solid substances collected by the recovery device collector are removed, and removed substances containing the removed iron-based solid substances are returned to the reduction device side through the first removed substance returning line.
1. An exhaust gas treatment system, comprising:
a reduction device configured to perform a reduction process to turn iron oxide to reduced iron;
a CO 2 recovery device that includes:
a CO 2 absorbing tower configured to recover CO 2 with CO 2 absorbing liquid from exhaust gas containing at least iron-based solid substances and the CO 2 , which are discharged from the reduction device; and
an absorbing liquid regenerating tower configured to regenerate a lean solution having a low CO 2 concentration by diffusing the CO 2 from a rich solution having absorbed CO 2 , which is supplied from the CO 2 absorbing tower;
a lean solution supply line through which the lean solution regenerated in the absorbing liquid regenerating tower is extracted from the absorbing liquid regenerating tower and is introduced to the CO 2 absorbing tower to be reused in the CO 2 absorbing tower;
a branch liquid line branched from the lean solution supply line;
a recovery device collector that is provided to the branch liquid line and is configured to collect the iron-based solid substances contained in the lean solution; and
a first removed substance returning line through which the iron-based solid substances collected by the recovery device collector are removed, the first removed substance returning line for returning recovery device removed substances, which contain the iron-based solid substances that are removed, to the reduction device.
2. The exhaust gas treatment system for the exhaust gas from the reduction device according to claim 1 , wherein the collector includes an extraction line for extracting the rich solution from the CO 2 absorbing tower and a liquid filtrate supply line for returning liquid filtrate obtained after collecting the iron-based solid substances to the CO 2 absorbing tower.
3. The exhaust gas treatment system according to claim 1 , further comprising:
a cooling tower provided on upstream of the CO 2 absorbing tower, the cooling tower configured to cool the exhaust gas containing at least the iron-based solid substances and the CO 2 , which are discharged from the reduction device, with circulating cooling water;
a cooling tower collector configured to collect the iron-based solid substances contained in the circulating cooling water;
a cooling tower removing device configured to remove the iron-based solid substances collected by the cooling tower collector; and
a second removed substance returning line for returning cooling tower removed substances, which contain the iron-based solid substances removed by the cooling tower collector, to the reduction device.
4. The exhaust gas treatment system according to claim 3 , wherein the cooling tower collector device includes an extraction line for extracting the cooling water from the cooling tower and a liquid filtrate supply line for returning liquid filtrate obtained after collecting the iron-based solid substances to the cooling tower.
5. The exhaust gas treatment system according to claim 1 ,
wherein the recovery device collector includes a filter, and
wherein the filter comprises any one of a cartridge filter, a precoat filter, a metallic slit filter, a wire net filter, a sintered metal filter, and a magnetic filter, or combination thereof.
6. The exhaust gas treatment system according to claim 1 ,
wherein the recovery device collector includes a filter,
wherein the filter comprises any one of a cartridge filter, a precoat filter, a metallic slit filter, a wire net filter, and a sintered metal filter, or combination thereof, and
wherein the filter has a surface on which a filtering medium is provided, and the filtering medium is formed of iron-based compound particles coated with a resin that are accumulated on the surface of the filter.
7. The exhaust gas treatment system according to claim 1 ,
wherein the recovery device collector includes a filter,
wherein the filter comprises a magnetic filter,
wherein the magnetic filter has a surface on which a filtering medium is provided, and
wherein the filtering medium is formed of magnetic iron-based compound particles coated with a resin, and the magnetic iron-based compound particles are accumulated on the surface of the magnetic filter to which a magnetic field is applied.
8. The exhaust gas treatment system according to claim 3 ,
wherein the cooling tower collector includes a filter, and
wherein the filter comprises any one of a cartridge filter, a precoat filter, a metallic slit filter, a wire net filter, a sintered metal filter, and a magnetic filter, or combination thereof.
9. The exhaust gas treatment system according to claim 3 ,
wherein the cooling tower collector includes a filter,
wherein the filter comprises any one of a cartridge filter, a precoat filter, a metallic slit filter, a wire net filter, and a sintered metal filter, or combination thereof, and
wherein the filter has a surface on which a filtering medium is provided, and the filtering medium is formed of iron-based compound particles coated with a resin that are accumulated on the surface of the filter.
10. The exhaust gas treatment system according to claim 3 ,
wherein the cooling tower collector includes a filter,
wherein the filter comprises a magnetic filter,
wherein the magnetic filter has a surface on which a filtering medium is provided, and
wherein the filtering medium is formed of magnetic iron-based compound particles coated with a resin, and the magnetic iron-based compound particles that are accumulated on the surface of the magnetic filter.