FIELD: chemistry.
SUBSTANCE: present invention relates to a method of producing ammonia-urea. Liquid ammonia (20) containing minor amounts of hydrogen, nitrogen, methane and optionally other urea-inert gases is produced with an ammonia synthesis process operated at a given ammonia synthesis pressure, and at least a portion of said liquid ammonia is used to provide ammonia (24) input stream of a urea 16 synthesis process. Liquid ammonia formed from said ammonia synthesis process is treated directly at said ammonia synthesis pressure at steps of cleaning, intended for removal of inert urea gases, and therefore input stream of ammonia (24), suitable for said urea synthesis process at pressure close to specified ammonia synthesis pressure. Purification process includes at least following steps: a) cooling of liquid ammonia (20) to produce cooled flow of liquid ammonia (21), b) separating gaseous fraction (22), including hydrogen and methane from said cooled liquid ammonia to produce purified liquid ammonia (23) at high pressure, and c) repeated heating said purified liquid ammonia (23) after separation of said gaseous fraction, wherein reheated purified ammonia (24) is obtained at temperature suitable for feeding into urea synthesis process. Invention also discloses apparatus for producing ammonia-urea and method for synthesis of ammonia-urea.
EFFECT: higher efficiency of method of feeding ammonia from ammonia section to urea section.
13 cl, 5 dwg
