the angle between the staggerd larger holes 162 is 10 u00b0 for holes of this exemplary type and dimension the flow rate for urea solution for a 35 solution can be between about 0 1 and about 10 liters per minute and the gas flow rate can be between about 50 and about 1000 cubic feet per minute the urea injector 18 introduces finely dispersed particles or droplets the spray pattern 19 is preferably designed to be conical or otherwise as will provide uniform distribution any suitable injector or nozzle can be employed e g air assisted airless and mechanical atomizers can be utilized droplet or particle sizes less than 500 microns but typically less than 100 and preferably below 50 microns are desirable to rapidly evaporate any water and decompose the urea also in consideration of vessel size small and slow droplets generated from e g ultrasonic nozzles can be more desirable than large and fast droplets if desired steam can be utilized as an atomizing fluid urea feed line 20 can provide a central channel for the urea and a surrounding annular channel for the atomizing fluid which can protect the urea from decomposition in the line 20 prior to exiting the injector 18 the heated gases entering chamber 10 via inlet 12 will gasify the urea by pyrolyzation and or hydrolysis and the gases containing gasified urea exit from the chamber 10 via outlet 14 the gases are preferably introduced into the chamber 10 at a temperature of at least 400 u00b0 f preferably greater than 500 u00b0 f and more preferably from about 600 u00b0 f to about 1300 u00b0 f e g from about 700 u00b0 f to about 1200 u00b0 f the temperature of the gases and the residence time prior to exit.