Residual fuels catalytic cracking

In the 1970 s, heavy fuel came mainly from atmospheric distillation residue. Nowadays a very large proportion of this product is vacuum distilled and the distillate obtained is fed to conversion units such as catalytic cracking, visbreaking and cokers. These produce lighter products —gas and gasoline— but also very heavy components, that are viscous and have high contaminant levels, that are subsequently incorporated in the fuels. 

Since the war the demand for gasoline, jet, and diesel fuels has grown, while the demand for heavy industrial fuel oils has declined. Furthermore, many new oil finds have yielded heavier crudes, therefore the need to convert residue components into lighter oils for feedstock for catalytic cracking. 

The main use of residual fuel oil is for power generation. It is burned in direct-fired furnaces and as a process fuel in many petroleum and chemical companies. Due to the low market value of fuel oil, it is used as a feedstock to catalytic and thermal cracking units. 

Gulf HDS A process for hydrorefining and hydrocracking petroleum residues in order to make fuels and feeds for catalytic cracking. Developed by the Gulf Research Development Company. See also hydrodesulfurization. 

Petroleum coke is the residue left by the destructive distillation (thermal cracking or coking) of petroleum residua. The coke formed in catalytic cracking operations is usually nonrecoverable because of adherence to the catalyst, as it is often employed as fuel for the process. The composition of coke varies with the source of the crude oil, but in general, is insoluble on organic solvents and has a honeycomb-type appearance. 

Solvent deasphalting is carried out primarily to recover lube or catalytic cracking feedstocks from asphaltic residuals, with asphalt as a byproduct. Propane deasphalting is the predominant technique. The vacuum fractionation residual is mixed in a fixed proportion with a solvent in which asphalt is not soluble. The solvent is recovered from the oil via steam stripping and fractionation, and is reused. The asphalt produced by this method is normally blended into fuel oil or other asphaltic residuals. 

In response to recent federal and local environmental concerns (e.g., industrial emission controls and lead phase-out) and to the growing interest of refiners in cracking residual fuels, researchers have generated new families of cracking catalysts. There is now a need to review the merits of these newly developed materials. This volume contains contributions from researchers involved in the preparation and characterization of cracking catalysts. Other important aspects of fluid catalytic cracking, such as feedstocks and process hardware effects in refining, have been intentionally omitted because of time limitations and should be treated separately in future volumes. 

The cracked liquid products boiling above gasoline have been utilized in Diesel, distillate, and residual fuels, in addition to catalytic recycling and thermal cracking for additional gasoline yield (4, 6, 7,16, 21). 

With this decision made, Ashland set out to develop a new residual oil conversion process which could effectively produce a greater amount of transportation fuel from each barrel of crude processed. It was concluded that a new process would take the best features from the fluid catalytic cracking process and couple them with innovative improvements in related key areas such as unique... 

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