Conversion of urea to reactants for NO
The invention provides a system for converting urea into reactants useful for removing NO X from industrial emissions. The system includes a urea inlet, a steam inlet, and a reactor in fluid communication with the urea inlet and the steam inlet. The reactor is configured and adapted to inject urea from the urea inlet into a steam flow from the steam inlet to convert the urea into at least one reactant for NO X reduction within a substantially gaseous mixture. The invention also provides a method of converting urea into reactants for reducing NO X out of industrial emissions. The method includes injecting urea into a steam flow to convert the urea into at least one reactant for NO X reduction within a substantially gaseous mixture.
1. A method for converting urea into reactants for reducing NO x out of industrial emissions, the method comprising injecting urea into a steam flow to convert the urea into at least one reactant for NO x reduction through hydrolysis inside droplets flowing within a substantially gaseous mixture.
2. A method for converting urea as recited in claim 1 , wherein the step of injecting includes converting urea into at least one reactant for NO x reduction through a chemical process including hydrolysis and decomposition.
3. A method for converting urea as recited in claim 1 , wherein the step of injecting includes atomizing urea through a nozzle.
4. A method for converting urea as recited in claim 1 , wherein the flow of steam is superheated steam.
5. A method for converting urea as recited in claim 1 , further comprising a step of converting substantially all of the urea from the substantially gaseous mixture.
6. A method for converting urea as recited in claim 1 , further comprising a step of pre-heating the urea prior to injection into the reactor.
7. A method for converting urea as recited in claim 1 , wherein the substantially gaseous mixture has a temperature in excess of about 600° F.
8. A method for converting urea as recited in claim 1 , wherein the substantially gaseous mixture has a temperature in excess of about 650° F.
9. A method for converting urea as recited in claim 1 , wherein the substantially gaseous mixture has a temperature in excess of about 1000° F.
10. A method for converting urea as recited in claim 1 , wherein the substantially gaseous mixture has a temperature in the range of about 500° F. to about 1600° F.
11. A method for converting urea as recited in claim 1 , wherein the substantially gaseous mixture has a temperature in the range of about 1000° F. to about 1050° F.
12. A method for converting urea as recited in claim 1 , further comprising a step of heating a reactor containing the substantially gaseous mixture to maintain at least a portion of the surface of the reactor at an elevated temperature to prevent condensation thereon.
13. A method for converting urea as recited in claim 1 , further comprising a step of controlling conversion of urea within the substantially gaseous mixture in a reactor including:
a) a first control loop operatively connected to the reactor to control urea injection rate based on demand for NO x reduction;
b) a second control loop operatively connected to the reactor to control temperature of the substantially gaseous mixture upstream from a reducer; and
c) a third control loop operatively connected to the reactor to control temperature of the substantially gaseous mixture downstream from the reducer.
14. A method for converting urea as recited in claim 1 , further comprising a step of controlling conversion of urea within the substantially gaseous mixture in a reactor including:
a) a first control loop operatively connected to the reactor to control urea injection rate based on demand for NO x reduction;
b) a second control loop operatively connected to the reactor to control the ratio of steam from the steam inlet to urea from the urea inlet; and
c) a third control loop operatively connected to the reactor to control temperature of the substantially gaseous mixture downstream from a reducer.
15. A method for converting urea as recited in claim 1 , further comprising a step of exposing urea to a catalyst to facilitate urea conversion.
16. A method for converting urea as recited in claim 15 , wherein the step of exposing includes adding a catalyst to a urea source.
17. A method for converting urea as recited in claim 16 , further comprising a step of recovering the catalyst after the step of exposing urea to the catalyst to preserve the catalyst for reuse.
18. A method for converting urea as recited in claim 1 , further comprising a step of mixing solid urea with water to produce an aqueous solution of urea prior to the step of injecting.
19. A method for converting urea as recited in claim 1 , further comprising a step of heating solid urea to produce molten urea for injecting.