Process differences between rapid heavy oil cracking and catalytic cracking of heavy oil

Rapid cracking of heavy oil? I’ve never heard of that. I think it must differ in principle from catalytic cracking. Literally, the rapid pyrolysis of heavy oil should be a thermal pyrolysis reaction, and its mechanism should be based on the principles of radical reactions ； Catalytic cracking, on the other hand, is based on the reaction mechanism of carbocations ； Please have the sea friends who have seen it come up and answer

As far as I know, rapid cracking of heavy oil is synonymous with catalytic cracking... haha... At present, some companies, in order to facilitate and smooth the approval process for their projects, change the name of catalytic cracking units; some call it heavy oil upgrading, some call it steam catalytic cracking of heavy oil, and some call it processing of heavy oil... The names vary. In fact, cracking and catalytic cracking are strictly different chemical processes, differing in terms of temperature and whether a catalyst is used or not. For more details, refer to the book on the principles of petroleum cracking written by Zou Renjian... :lol

I’ve never heard of rapid pyrolysis of heavy oil; I’m only familiar with thermal cracking, catalytic cracking, or hydrocracking of heavy oil. Thermal cracking (or viscosity-reducing cracking) does not use a catalyst; the reaction temperature is generally low, around 390–430°C, and the products include gases, gasoline, diesel, and heavy distillates. Catalytic cracking uses molecular sieve catalysts, with a reaction temperature of around 500°C (the temperature at the exit of the riser reactor). The products include gases, liquefied gas, gasoline, diesel, oil slurry, and coke (attached to the catalyst). Pyrolysis and cracking are quite different from each other. The differences between catalytic cracking and pyrolysis are as follows: ① Different purposes. Catalytic cracking is aimed at producing light hydrocarbons such as gasoline, kerosene, and diesel, whereas catalytic pyrolysis is intended to produce basic chemical feedstocks such as ethylene, propylene, butylenes, and butadiene. 　　② The raw materials are different. The feedstocks for catalytic cracking are generally vacuum distillate oil, coker wax oil, atmospheric residue, and a mixture of vacuum distillate oil and vacuum residue ； The range of feedstocks for catalytic cracking is relatively wide; it can include materials used in catalytic cracking, as well as naphtha, diesel, and light hydrocarbons such as C4 and C5. 　　③ The catalysts are different. Catalysts for catalytic cracking are generally zeolite molecular sieve catalysts and aluminum silicate catalysts, whereas catalysts for catalytic pyrolysis are generally zeolite molecular sieve catalysts and metal oxide catalysts. 　　④ The operating conditions are different. Compared to catalytic cracking, catalytic pyrolysis operates at higher reaction temperatures, uses a larger ratio of catalyst to oil, requires more steam, has a shorter residence time for the oil and gas, and experiences more severe secondary reactions. 　　⑤ The reaction mechanisms are different. The reaction mechanism of catalytic cracking is generally considered to be the carbocation mechanism, whereas the reaction mechanism of catalytic pyrolysis includes both the carbocation mechanism and the radical mechanism. Petroleum cracking generally refers to the steam cracking of hydrocarbons to produce olefins; the raw materials used are mostly naphtha or light diesel and heavy diesel, with heavy oil being used rarely. Domestic pyrolysis process technologies involving heavy oil include: 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 simultaneously producing high-octane premium gasoline. ②Catalytic 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. Based on traditional catalytic cracking technology, it uses heavy oils such as wax oil, wax oil blended 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. ③Process for producing ethylene via direct cracking of heavy oil (HCC process). This process was developed by the Refining Research Institute of Luoyang Petrochemical Engineering Company; it is a catalytic cracking process that produces ethylene directly from heavy oil, while also generating propylene, butylene, and light aromatics. It draws on mature heavy oil catalytic cracking processes, employs fluidized \"reaction-regeneration\" technology, and uses riser reactors or downflow reactors to meet the requirements of high temperature and short contact time in the process. This post was last edited by hgshy on 2009-2-12 23:54]

It’s purely to change the name for the convenience of applying for the project