A301氨合成催化剂最佳操作条件与催化活性的关系

用高压氨合成催化剂性能评价装置 ,研究了反应温度、压力、空速、惰性气体含量、氢氮比和催化剂粒度对 A30 1催化剂活性的影响。A30 1催化剂在 15 MPa下的最适反应温度在 430～ 480℃ ,在 7MPa下在 376～ 45 0℃ ,比 A110 - 2低 15～ 35℃。A30 1催化剂的最佳 H2 ,N2 摩尔比 nm在 45 0℃时为 2 .5 5～ 3.0 ,在 40 0℃时为 2 .2 3～ 2 .5 5 ,在 35 0℃时为 1.76～ 2 .2 2 ,并可用 nm=1 .5 0 +1 .49( c NH3/ c*NH3)来表示。惰性气体含量会使催化剂活性大幅度降低 ,每当惰性气体含量增加 1 % ,出口氨浓度 (氨净值 )平均降低 0 .2 %～ 0 .3 5 %。颗粒大小对活性或反应速率有严重的影响 ,其内表面利用率受反应温度和催化效率两个因素的影响 ,对于高活性的 A3 0 1催化剂 ,催化效率的因素起主要作用。根据实验结果和合成氨反应的基本理论 ,讨论并提出了A3 0 1催化剂在合成氨生产中的最佳操作工艺条件

OPTIMAL OPERATION CONDITIONS OF AMMONIA SYNTHESIS AND CATALYTIC ACTIVITY FOR A301 CATALYST

The influences of temperature, pressure, space velocity, concentration of inert gas, ratio of hydrogen to nitrogen and particle size on the activity of A301 catalyst were investigated. The optimal reaction temperatures for A301 catalyst are in the range of 430～480℃ at 15MPa of pressure and 376～450℃ at 7MPa of pressure, 15～35℃ lower than A110-2 catalyst. The optimal ratios of hydrogen to nitrogen nm　for A301 catalyst are 2.55～3.0, 2.23～2.55 and 1.76～2.22 at temperature of 450, 400 and 350℃ respectively, and may be expressed by equation of nm =1.50+1.49(cNH3/cNH3*). The more the content of inert gas (CH４＋Ar), the lower the outlet ammonia concentration. When the content of inert gas increased by one percent, the outlet ammonia concentration lowered 0.2％～0.35%. The use ratio of inner face of a catalyst is not only related to the particle size but also to temperature and catalytic efficiency. But the catalytic efficiency acts mainly for high active A301 catalyst. According to the experiment results and the principle of ammonia synthesis, optimal operation conditions of ammonia synthesis on the A301 catalyst were proposed.