Cracking, in petroleum refining

Couper, Archibald S., 3 Coupling constant (J), 503, 506, 507-508 dihedral angle dependence, 544 Covalent bond, 12-14, 44 Cracking, in petroleum refining, 70 Crafts, James M., 451 m-Cresol, 939 acidity of, 944... 

Bonifay. R. Marcilly, C. Catalytic Cracking. In Petroleum Refining, Vol. 3 Conversion Processes Ceprince, P.,Ed. Technip Editions, 2001 169-227. Chap. 5. 

Cracking (Section 2 16) A key step in petroleum refining in which high molecular weight hydrocarbons are converted to lower molecular weight ones by thermal or catalytic carbon-carbon bond cleavage... 

Catalytic Pyrolysis. This should not be confused with fluid catalytic cracking, which is used in petroleum refining (see Catalysts, regeneration). Catalytic pyrolysis is aimed at producing primarily ethylene. There are many patents and research articles covering the last 20 years (84—89). Catalytic research until 1988 has been summarized (86). Almost all catalysts produce higher amounts of CO and CO2 than normally obtained with conventional pyrolysis. This indicates that the water gas reaction is also very active with these catalysts, and usually this leads to some deterioration of the olefin yield. Significant amounts of coke have been found in these catalysts, and thus there is a further reduction in olefin yield with on-stream time. Most of these catalysts are based on low surface area alumina catalysts (86). A notable exception is the catalyst developed in the former USSR (89). This catalyst primarily contains vanadium as the active material on pumice (89), and is claimed to produce low levels of carbon oxides. 

Ethylene as a By-Product. The contribution to world ethylene production is small, but not zero. In petroleum refining fluid catalytic cracking (FCC) units, small amounts of ethylene are produced but generally not recovered, except in a few locations where large FCC units are adjacent to petrochemical faciUties. 

Cracking (Chapter 3 Focus On) A process used in petroleum refining in which large alkanes are thermally cracked into smaller fragments. 

They are not found to any extent in natural products, but are produced in the destructive distillation of complex natural substances, such as coal, and are formed in large amounts in petroleum refining, particularly in the cracking process. The first member of the series is ethylene, C2H4. The dienes contain two double bonds between pairs of carbon atoms in the molecule. They are related to the complex hydrocarbons in natural rubber and are important in the manufacture of synthetic rubber and plastics. The most important members of this series are butadiene, C4H5 and isoprene, CsHg. 

A species frequently maintains phase equilibrium while it is reacting in one phase. An example is hydrocracking of heavy hydrocarbons in petroleum refining, where H2 from the vapor dissolves into the liquid hydrocarbon phase, where it reacts with large hydrocarbons to crack them into smaller hydrocarbons that have sufficient vapor pressure to evaporate back into the vapor phase. As long as equilibrium of the species between phases is maintained, it is easy to calculate the concentrations in the hquid phase in which reaction occurs. 

Fluid catalytic cracking has been one of the key processes in petroleum refining for the last SO years. The first commercial fluid catalytic cracking... 

What are typical operating conditions (temperature, pressure) of a catalytic cracking reactor used in petroleum refining ... 

Fl ld. A typical catalytic cracking reactor used in petroleum refining operates at 88S-1020 F and 10-30 psig. Chemical Process Industries. R.C. Shreve and JA. Brink. Jr.. 4th ed.. New York - McGraw - Hill Book Co.. Inc., 1977. p. 675. 

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