Composition of reforming catalyst

The reforming catalyst consists of a metallic component (platinum or platinum-containing bimetallic or polymetallic), a carrier (usually alumina) and an acidic component (chloride or fluoride). The metal components (mainly the precious metal platinum) are highly dispersed to the alumina carrier. It is a multifunctional catalyst with both dehydrogenation and hydrogenation activity (mainly carried by platinum) and isomerization and hydrocracking activity (carried by support or halogen).

Some chemical reactions in the process of catalytic reforming, such as dehydrogenation and hydrolysis, are mainly carried out on the active centers of metals. Some are mainly carried out on the acid center, such as alkane isomerization and hydrocracking. Others need to be carried out under the cooperation of two kinds of centers, such as dehydrogenation cyclization. Therefore, the reforming catalyst must have a variety of functions, the metal function and acid function in the process of the reaction must be organically coordinated in order to obtain satisfactory reaction results. Catalyst has a very important effect on product yield and quality in reforming process.

The composition of catalytic reforming catalyst is more complex and more expensive than FCC catalyst and hydrogenation catalyst. 

1）The main carrier is alumina, among which η- alumina accounts for 0%~10%, the rest is γ- alumina; Silicon oxide accounted for 0.001%~2%. The function is to carry the active component and disperse it evenly.

2）Active metal components platinum (and palladium), called the main agent, content of 0.01%~0.7%. Bimetallic or polymetallic reforming catalysts also introduce 0.005% to 10% of non-precious metals, known as additives, usually selected from rhenium, tin, titanium, iridium, germanium, gallium, lead, molybdenum and tungsten. Rhenium is the most commonly used, followed by tin and iridium. The main function of the co-catalyst is to promote the dispersion of platinum, inhibit the growth of platinum grains, improve stability, improve selectivity, enhance the capacity of carbon capacity, so that the device can operate at low pressure, low hydrogen-oil ratio and high temperature for a long period. Sometimes 0.001%~10% doping metal, mainly alkali metal and one of the alkali earth metals, is introduced to improve the mechanical properties of the catalyst. But as long as the catalytic reforming catalyst, all contain the active metal platinum, just how much.

3）The acidic component is usually chlorine, the content is 0.1%~15%; There are those that choose other halogens. The main function is to promote the isomerization and cracking of catalyst.