Purpose of adding non-metallic substances to activated alumina desiccant

In many cases, we will add some non-metallic materials to the activated alumina desiccant. What will they do.

1、 The introduction of chlorine increases the acidity of acid sites with weak original acid strength on the activated alumina desiccant, and increases the acid content of acid sites with acid strength greater than 100kJ/mol, and speculates on the formation mechanism of acid sites of activated alumina:

2、 With the addition of fluorine, due to its high electronegativity, it has a strong polarization effect on the alumina lattice, weakening the strength of the O-H bond, thus enhancing the acidity of the surface hydroxyl (that is, enhancing the strength of the B acid), and the strength of the residual acid taste is also increased due to the induction effect of fluorine.

3、 Fluorine treatment is an effective method to enhance the acidity of activated alumina desiccant. However, excessive fluoride treatment will destroy the structure of alumina and the newly formed acid taste, which will weaken the strong acid peak. The performance evaluation experiment has proved that.

4、 Phosphorus doped active alumina desiccant not only has more moderate acidity and is not easy to coke, but also can significantly improve the hydrogenation selectivity and stability of the catalyst.

5、 When studying the acid regulation and coke deposition behavior of phosphorus modification on activated alumina desiccant, it was found that with the increase of phosphorus content, the amount of strong acid gradually decreased, the amount of medium strong acid changed in a peak curve, the amount of weak acid and total acid in a valley curve, and the phosphorus content corresponding to the peak and valley was about 0.75%. The addition of phosphorus can effectively adjust the acid amount and acid strength distribution of activated alumina.

This is all we have to say about the non-metallic substances added to the activated alumina desiccant. If you want to know more, you can consult the manufacturer.