NOx reduction process in a cement kiln manufacturing system

1. A bypass system for use with off gases that have exited a cement kiln utilized in a cement making process comprising:

i) means to direct from about 10% to about 70% by mass of the off gases into a bypass duct;

ii) means to remove NOx present in the off gases while the off gases are in the bypass duct;

(iii) means to remove volatile components present in the off gases while the off gases are in the bypass duct; and

wherein the off gases are redirected to the cement making process after NOx and volatile components removal steps.

2. A process to remove NOx from dust and volatile containing off gases from a cement kiln as said kiln is being utilized in a cement making process comprising:

i) withdrawing the NOx containing kiln off gases from a location in the cement making process at which the temperature of such off gases is at least about 1150° C.;

ii) reducing the temperature of such gases to a temperature that is suitable for reagent injection;

iii) inserting a reagent into the off gases, said reagent reacting with the NOx in the off gases to thereby remove NOx from said off gases; and

iv) subjecting the off gases to a second temperature reducing step to condense volatiles on the dust present in the kiln off gases.

3. The process of claim 2 wherein the reagent is ammonia or urea.

4. A bypass system for use with off gases that have exited a cement kiln utilized in a cement making process comprising:

i) means to direct from about 10% to about 70% by mass of the off gases into a bypass duct;

ii) means to remove NOx present in the off gases while the off gases are in the bypass duct;

(iii) means to remove volatile components present in the off gases while the off gases are in the bypass duct; and

wherein the off gases are inserted into a raw meal crushing means after the NOx and volatile components removal steps.