The development of the A301 based on Fe 1-x O ammonia synthesis catalyst has for the first time allowed ammonia to be made economically at pressure close to those of gas production.The high activity and long life of the catalyst has been proved over a period of nine years in hundreds of 150-500t/d scale converter charges.In this paper

the activity test of A301 catalyst for use at low pressure was carried out in a equipment

called"sidestream"reactor

in which the catalyst was present as a packed bed of commercial-sized material and was subjected to 1000t/d scale plant conditions.The main results of the use of the sidestream reactor for the testing of catalysts are as follows:the outlet ammonia concentrations of the sidestream reactor under plant conditions are 14.35%-16.55%

15.24%-16.66% and 17.2%-18.8% by volume at 7.0

8.5 and 10.0MPa of pressure respectively.A301 is the most active of all iron catalysts tested for low pressure and low temperature operation and is the only catalyst that has been demonstrated to work efficiently at pressures in the region of 7-10MPa.