Regarding DCC treatment of heavy oil

① Catalytic cracking process (DCC process). This process was developed by the Sinopec Research Institute of Petrochemical Technology. It uses heavy oil as raw material, and solid acid selective molecular sieve catalysts to carry out cracking reactions under relatively mild conditions, thereby producing low-carbon olefins or isomerized olefins as well as high-octane gasoline. This process draws on fluidized catalytic cracking technology, utilizing catalyst fluidization, continuous reaction, and regeneration techniques, and has been brought to industrial application. The DCC process has two operating modes—DCC-Ⅰ and DCC-Ⅱ. DCC-Ⅰ operates under relatively stringent conditions, carrying out the reaction in a riser-type dense-phase fluidized bed reactor to produce large quantities of gaseous olefins primarily composed of propylene ； DCC-Ⅱ operates under milder conditions in a riser reactor to maximize the production of small molecular olefins such as propylene, isobutylene, and isopentene, while also producing high-octane high-quality gasoline. ② Catalytic thermal cracking process (CPP process). This process is a patented technology developed by the Sinopec Research Institute of Petrochemical Technology for the production of ethylene and propylene. Building on traditional catalytic cracking technology, it uses heavy oils such as wax oil, wax oil mixed with residue oil, or atmospheric residue oil as raw materials. A riser reactor, specially developed catalysts, and a continuous reaction-regeneration cycle system for the fluidized transport of catalysts are employed to produce ethylene and propylene under milder operating conditions compared to steam cracking. The CPP process was developed on the basis of the catalytic cracking DCC process, and its key technology lies in further improving the process and catalysts to change the target product from propylene to ethylene and propylene.