PROCESS FOR THE PREPARATION OF UREA

1. Process for the preparation of urea from ammonia and carbon dioxide, characterized in that in a plant for the preparation of urea the waste gases released at virtually atmospheric pressure are compressed by an ejector driven by the waste gas from the high-pressure synthesis and are supplied to a medium-pressure absorber. 2. Process according to Claim 1, characterized in that the pressure of the waste gases released at virtually atmospheric pressure is increased by between 0.15 and 2 MPa. 3. Process according to Claim 2, characterized in that the pressure of the waste gases released at virtually atmospheric pressure is increased by between 0.2 and 0.5 MPa. 4. Process for improving and optimizing existing urea plants by increasing the pressure of the waste gases from an absorber operating at virtually atmospheric pressure with an ejector driven by the waste gas from the synthesis and supplying the said waste gases to a medium-pressure absorber. 5. Process according to Claim 4, characterized in that the pressure of the waste gases from an absorber operating at virtually atmospheric pressure is increased by between 0.15 MPa and 2 MPa. 6. Process according to Claim 4, characterized in that the pressure of the waste gases from an absorber operating at virtually atmospheric pressure is increased by between 0.2 MPa and 0.5 MPa. Раскрывается способ получения мочевины из аммиака и диоксида углерода, в котором отходящие газы, выделяющиеся практически при атмосферном давлении с установки синтеза мочевины, сжимают с помощью эжектора, приводимого в движение газом, отходящим со стадии синтеза при высоком давлении, и подают в абсорбер среднего давления. Давление отходящих газов повышают на 0,15-1 МПа.