Apparatus and system for NO
View Patent ↗The present invention relates to a method and a system for cleaning a CO 2 rich flue gas stream containing water vapor and NO X prior to CO 2 sequestration. The method and system include heating the flue gas stream to a temperature suitable for selective catalytic reduction (SCR) of NO X in a flue gas heater, reducing at least some of the NO X in the heated flue gas stream to N 2 by SCR, and removing at least some of the water vapor from the NO X depleted flue gas stream by adsorption in an adsorption drier.
1. A method of cleaning a CO 2 rich flue gas stream containing water vapor and NO X prior to CO 2 sequestration, said method comprising:
heating the flue gas stream to a temperature suitable for selective catalytic reduction (SCR) of NO X ;
reducing at least some of the NO X in the heated flue gas stream to N 2 by SCR; and
removing at least some of the water vapor from the NO X depleted flue gas stream by adsorption in an adsorption drier.
2. The method according to claim 1 , further comprising subjecting the flue gas stream to dust removal prior to heating the flue gas stream.
3. The method according to claim 1 , further comprising subjecting the flue gas stream to sulfur dioxide removal prior to heating the flue gas stream.
4. The method according to claim 1 , further comprising subjecting the flue gas stream to flue gas condensation prior to heating the flue gas stream.
5. The method according to claim 1 , wherein said temperature is the range of 190° C. to 500° C.
6. The method according to claim 1 , wherein said temperature is the range of 200° C. to 250° C.
7. The method according to claim 1 , wherein said heating comprises:
pre-heating the flue gas stream to a first temperature by indirect heat-exchange with the flue gas stream resulting from the SCR; and then
super-heating the pre-heated flue gas stream to a second temperature in the range of 190° C. to 500° C.
8. The method according to claim 7 , wherein said second temperature is the range of 200° C. to 250° C.
9. The method according to claim 1 wherein said adsorption drier comprises an adsorbent selected from the group consisting of molecular sieves, zeolite and silica gel.
10. A flue gas treatment system ( 3 ) for cleaning a CO 2 rich flue gas stream containing water vapor and NO X prior to CO 2 sequestration, said system comprising:
a flue gas heater configured to heat the flue gas stream to a temperature suitable for selective catalytic reduction of NO X ;
a selective catalytic reduction reactor (SCR reactor) configured to receive heated flue gas from the flue gas heater and reduce at least some of the NO X in the heated flue gas stream to N 2 by selective catalytic reduction;
an adsorption drier configured to remove at least some of the water from the NO X depleted flue gas stream by adsorption.
11. The flue gas treatment system according to claim 10 , further comprising a dust removal filter arranged upstream of the flue gas heater.
12. The flue gas treatment system according to claim 10 further comprising a scrubber for sulfur dioxide removal upstream of the flue gas heater.
13. The flue gas treatment system according to claim 10 further comprising a flue gas condenser arranged upstream of the flue gas heater.
14. The flue gas treatment system according to claim 10 wherein said flue gas heater comprises:
a flue gas pre-heater configured to heat the flue gas stream to a first temperature by indirect heat-exchange with the flue gas stream leaving the SCR reactor; and
a flue gas super-heater configured to heat the pre-heated flue gas stream to a second temperature in the range of 190° C. to 500° C.
15. The flue gas treatment system according to claim 14 , wherein said second temperature is in the range of 200° C. to 250° C.
16. The flue gas treatment system according claim 10 wherein said adsorption drier comprises an adsorbent selected from the group consisting of molecular sieves, zeolite and silica gel.