Methods and apparatus for continuously, quantitatively producing gaseous
ammonia from urea, including the steps of: dissolving urea in water to form concentrated
aqueous urea comprising at least 77 wt. % urea; continuously feeding the concentrated
aqueous urea into a reactor; continuously feeding a separate, additional supply
water into the reactor to form an aqueous urea reaction mixture; heating the aqueous
urea reaction mixture; and continuously withdrawing a gas phase product including
ammonia from the reactor, is disclosed. Also disclosed are methods and apparatus
for continuous and batchwise dissolution of urea to form aqueous urea solutions.
