Energy integration in ammonia production

摘要

Since its introduction by Haber and Bosch in the early twentieth century, the catalytic synthesis of ammonia from atmospheric nitrogen has become one of the worlds most important chemical manufacturing processes. Unfortunately, the process requires the use of significant amounts of energy, the European Fertilizer Manufacturers Association giving total average energy use per tonne of ammonia produced in 2000 as 37.4 GJ, EFMA. If 1500 tonnes of ammonia per day is taken to be a typical plant output this represents an average power requirement of 649 MW. It is the reduction of this energy input that is currently being addressed by research at the University of Durham and Terra Nitrogen (UK) Ltd. The paper will concentrate on the major processes that go to make up the industrial ammonia synthesis process as a whole and their interdependent nature. Examples of energy saving options will be given, focusing on the importance of using an integrated approach to avoid upsetting the sensitive energy balance. The value of using computer simulation as a tool to model process changes off-line will be discussed and the direct applicability of this work to other industries will be shown.