含氨废水处理技术及工艺设计方案

本文根据氮肥厂废水的特点，研究了高浓度氨氮废水的处理方法-吹脱法的除氨机理和氨氮去除率的影响因素。针对pH值和温度对氨氮去除率的影响，我们做了实验，结果表明若去除率要达到90％以上，pH值必须大于12且温度高于90C。同时可以用CaO将废水的pH值调节到12以上。最后，针对这种废水的处理设计了可行的工艺方案。     

浅论燃料甲醇的前景

我国今后的能源结构中,煤化工将扮演越来越重要的角色。引用大量数据说明燃料甲醇是一种新型车用燃料,燃料甲醇可充分利用国内的现有单醇、联醇装置生产能力。燃料甲醇的应用市场开发具有现实意义,并提出一些建议。     

天然沸石和硅酸钙滤床的脱氨除磷效能

利用天然沸石和硅酸钙为介质的过滤装置处理含氮磷的污水处理厂出水,研究天然沸石和硅酸钙材料对氨氮和磷酸盐的吸附性能。通过静态试验,得出了天然沸石粉末对氨氮和硅酸钙粉末的磷酸盐吸附容量分别为5.76mg NH4＋-N/g沸石和60mg PO43--P/g硅酸钙。并通过此装置研究了天然沸石、硅酸钙去除氨氮、磷酸盐的合适工艺参数,为生态型脱氨除磷装置的工程应用奠定基础。     

The mechanism of the poisoning of ammonia synthesis catalysts by oxygenates O2, CO and H2O: an in situ method for active surface determination

The effect of adding an oxygenated poison (O₂, CO or H₂O) to a hydrogen/nitrogen stream producing ammonia over a triply promoted (K₂O, CaO, Al₂O₃) commercial catalyst is not unsurprisingly rapidly to poison the catalyst. However, immediately the oxygenated poison reacts with the catalyst and before total poisoning has occurred, which in these experiments took 10 min, there was an explosive release of ammonia producing concentrations in the gas phase in excess of the equilibrium value. This is thought to be due to a convulsive reorganisation of the surface of the catalyst in forming regions of an oxide overlayer, resulting in the expulsion of the standing surface nitrogen atom coverage as ammonia. However, in contradistinction to the observation of complete poisoning of the triply promoted catalyst shortly after switching the water (2.9%) into the hydrogen/nitrogen stream, when polycrystalline iron was used as the catalyst, after the initial pulse of ammonia was observed, the small quantity of water (2.9%) in the hydrogen/nitrogen stream resulted in an increased rate ( ×3) of ammonia synthesis which declined only slightly over the twenty minute duration of the experiment. The difference in behaviour between the triply promoted catalyst and the polycrystalline iron is thought to be due to the relative ease of reduction of the latter, so that submonolayer quantities of oxide can be stabilised on the surface of the polycrystalline iron. The promoting effect of this oxide overlayer is either structural or electronic; no distinction can be made from these experiments. The technique of injecting either O₂ or CO into a hydrogen/nitrogen stream which is producing ammonia over promoted catalysts in quantities insufficient to cause complete poisoning and measuring the oxygen coverage of the catalyst to a measured decrease in the ammonia synthesis rate, appears to be a ready, in situ method for the determination of the active catalyst area.     

无外加热情况下氨合成塔生产的恢复

合成氨生产中,临时停车后合成塔生产的恢复,一般应在床温高于370℃或用电炉将床温加热到370℃以上的情况下进行。文章叙述了合成塔床温低至350℃,而电炉无法使用的条件下,直接给塔升压,通过反应热将床温升至正常操作指标,恢复生产的成功尝试。     

Selective catalytic reduction of NO by ammonia using mesoporous Fe-containing HZSM-5 and HZSM-12 zeolite catalysts: An option for automotive applications

Mesoporous and conventional Fe-containing ZSM-5 and ZSM-12 catalysts (0.5–8 wt% Fe) were prepared using a simple impregnation method and tested in the selective catalytic reduction (SCR) of NO with NH₃. It was found that for both Fe/HZSM-5 and Fe/HZSM-12 catalysts with similar Fe contents, the activity of the mesoporous samples in NO SCR with NH₃ is significantly higher than for conventional samples. Such a difference in the activity is probably related with the better diffusion of reactants and products in the mesopores and better dispersion of the iron particles in the mesoporous zeolite as was confirmed by SEM analysis. Moreover, the maximum activity for the mesoporous zeolites is found at higher Fe concentrations than for the conventional zeolites. This also illustrates that the mesoporous zeolites allow a better dispersion of the metal component than the conventional zeolites. Finally, the influence of different pretreatment conditions on the catalytic activity was studied and interestingly, it was found that it is possible to increase the SCR performance significantly by preactivation of the catalysts in a 1% NH₃/N₂ mixture at 500 °C for 5 h. After preactivation, the activity of mesoporous 6 wt% Fe/HZSM-5 and 6 wt% Fe/HZSM-12 catalyst is comparable with that of traditional 3 wt% V₂O₅/TiO₂ catalyst used as a reference at temperatures below 400 °C and even more active at higher temperatures.     

中小型氨合成装置如何选用亚铁基氨合成催化剂

指出了中小型氨合成装置合成催化剂选择与应用中存在的问题。对亚铁基氨合成催化剂的性能进行了比较详细的分析和介绍，并就新型氨合成催化剂的选择和使用提出了一些建议。     

天然气间歇转化系统的节能对策

通过对小型天然气氨厂的间歇转化系统进行分析．找到了能量损耗的原因和部位。改造后吨氨降低能耗９．６３ＧＪ。     

合成氨装置铜洗塔的技术改造

针对铜洗塔存在吸收液循环量不足等缺点,对其内件如填料、液体初始分布器和液体收集再 分布器等进行了技术改造。改造后,铜洗塔的生产能力提高20％以上。     

A110－1－H／A110－1型氨合成催化剂在双筐并流合成塔中的使用

在双筐并流氨合成塔中使用了Ａ１１０－１－Ｈ／Ａ１１０－１型氨合成催化剂，使用寿命达１７４０天，累计产氨４３８３７８ｔ．该催化剂组合具有低温活性好、易还原、高催化活性、高抗毒能力、良好的热稳定性与破碎强度等优点．