Changyi Petrochemical recently finished refrigerant circulation renovation in its 1.4-million-ton catalytic cracking unit, greatly raising the unit’s capacity. The renovation significantly reduced energy consumption, could save 12,000 tons of standard coal annually and yield profits of 175 million yuan ($28.8 million).
In 2012, the company decided to tap the unit’s potential by conducting a series of technical renovations on its cold-recycling catalyst circulation. The improved unit can make better use of the high-activity catalysts and greatly raise the liquid recovery ratio and octane value.
The renovation also realized the independent adjustment of reaction temperature and catalyst-to-oil ratio, providing adequate space and time for the secondary reaction of the gasoline and reducing the mutual interference between gasoline modification and heavy oil cracking. At the same time, main thermal cracking products (dry gas) were reduced, which was conducive to the reaction for thiophenic sulfur to be converted into hydrogen sulfide.