Cracking processes thermal

Visbreaking. Viscosity breaking (reduction) is a mild cracking operation used to reduce the viscosity of residual fuel oils and residua (8). The process, evolved from the older and now obsolete thermal cracking processes, is classed as mild because the thermal reactions are not allowed to proceed to completion. 

Lewis directed subterranean resei voir studies to improve the efficiency of extracting oil from the ground. He designed the first bubble tower to effect more precise and efficient fractionation operations and provided important assistance in developing one of the first continuous thermal cracking process. 

Visbreaking is a mild thermal cracking process that reduces the viscosity of heavy fuel oils and reduces the amount of low-viscosity blending stocks that must be added to the heavy residuals to meet viscosity specifications of the specific heavy fuel oil. The amount of heavy fuel oil production by a refinery is reduced by 20—30 percent if a visbreaker is used. The refinery profitability is improved with visbreaker operation, because heavy fuel oils are low value products. 

Coking is a severe thermal cracking process designed to handle heavy residues with high asphaltene and metal contents. These residues cannot be fed to catalytic cracking units because their impurities deactivate and poison the catalysts. 

There are two major commercial thermal cracking processes, delayed coking and fluid coking. Flexicoking is a fluid coking process in which the coke is gasified with air and steam. The resulting gas mixture partially provides process heat. 

Details are given of a pilot plant for the chemical recycling of plastics which has been established at Grangemouth, Scotland, by a consortium consisting of BP Chemicals, DSM, Elf Atochem, EniChem and Petrofina. The plant, capable of treating 300 tonnes of waste yearly, uses a low pressure, fluidised bed thermal cracking process. 

Blaugas An early thermal cracking process for making liquid petroleum gas from petroleum. Developed by the German company Blau in Augsburg from 1905. Not to be confused with blue gas (see Water gas). 

Dynacracking A petroleum cracking process which combines the best features of the "catalytic cracking and Thermal cracking processes. It converts heavy oil feedstocks to fuel gas, gasoline, and fuel oil. No catalyst is used. Developed in the 1950s by Hydrocarbon Research, but not commercialized. 

FTC [Fluid-bed thermal cracking] A continuous thermal cracking process for making synthesis gas from heavier petroleum fractions. 

Gyro Also called Gyro-cracking. An early vapor-phase thermal cracking process for refining petroleum. 

Jenkins An early liquid-phase thermal cracking process. See also Dubbs. 

Petrogas A thermal cracking process for converting heavy petroleum fractions to fuel gas. Developed by Gasco. 

TVP [True vapor-phase] A thermal cracking process in which vaporized petroleum oil is contacted with a hotter gas such that the temperature of the gas mixture is approximately 500°C. Used in the 1930s, but supplanted by various catalytic cracking processes. 

Visbreaking A thermal cracking process which reduces the viscosity of the residues from petroleum distillation, so that they may be handled at lower temperatures. It is essentially a high-temperature, noncatalytic pyrolytic process conducted in the presence of steam. See also HSC. 

Pyrolysis and liquefaction processes take an intermediate position in the sense that they maintain some larger molecular characteristics. Pyrolysis is a process in which the biomass material is quickly heated. The thermal cracking process, de-polymerizes waste or dry biomass and produces a liquid of complex composition (Fig. 1.17). 

The other thermal cracking process is visbreaking. This is a milder thermal process and is mainly used to reduce the viscosities and pour points of vacuum residues to... 

Fatty acids Result of thermal cracking processes... 

Gums Conjugated diolefins and other olefinic compounds formed during catalytic and thermal cracking processes heterocyclic compounds present in fuel can also initiate gum formation... 

Coking A refinery process in which fuel oil is converted to lower-boiling-point liquids and coke by a thermal cracking process. 

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