Reforming is the process of rearranging hydrocarbon molecules into new molecular structures under certain conditions. In the catalytic reforming process, the cyclic dehydrogenation of naphthenes and the cyclic dehydrogenation of alkanes are the main reactions to generate aromatics，at the same time, alkane isomerization and hydrocracking reactions will occur. The reforming products are mainly aromatic and iso-alkanes with high octane number and low olefin and sulfur. Therefore, catalytic reforming can obtain high octane gasoline and is an important means to produce light aromatic hydrocarbons such as benzene, toluene, xylene and hydrogen.

At present, the catalytic reforming process can be divided into four types: fixed-bed semi-regenerative reforming, cyclic regenerative reforming, catalytic continuous regenerative reforming, and low-pressure combined-bed reforming. Among them, the characteristics of the fixed bed semi-regenerative reforming process is that when the unit has been running for a long time, the carbon deposition on the catalyst has reached a certain amount, the activity has been greatly reduced, and the reaction temperature has risen, resulting the decline of liquid yield, hydrogen yield and economic benefit. As a result, the plant had to shut down or switch the reactor over, to allow the deactivated catalyst to be regenerated on-site in the reactor. Only after the catalyst activity is restored, the plant can enter the next production cycle.

Semi-regenerative reforming still plays an important role in reforming process due to its characteristics such as small investment, low operating cost and suitable for different production scale.

C6-C10 in naphtha

Semi-regenerative reforming process has low investment and operation cost comparing with continuous reforming. Although the aromatics yield is lower, yet the liquid yield is higher than that of continuous reforming.