| 摘要 |
An ammonia production process comprising synthesis gas generation and ammonia synthesis with heat recovery in the generation section by steam raising and steam superheating and heat recovery in the synthesis section by steam raising or boiler feed water heating is made more controllable by effecting part of the superheating in the synthesis section, so that a shut-down of the synthesis section results not only in a decrease in steam flow through the superheaters, but also in a decrease in the temperature of the steam fed to them. Thus overheating of the superheaters, a defect of some earlier processes, is avoided. The process is operated with a synthesis pressure under 150, preferably 40-80 bar abs. and preferably synthesis gas generation is based on primary hydrocarbon steam reforming at such a pressure that synthesis gas compression is by under 50%. |
