The two columns operate at different pressures with distillate streams having compositions close to their respective azeotropes.
Because each of the distillate fractions are taken out at different times, only one distillate exit point (location) is needed for a batch distillation and the distillate can just be switched to a different receiver, a fraction-collecting container.
"A great many different refined mineral spirits, petroleum distillates and petrochemicals as well as oxygenated solvents and chemicals can be used if they fall within the desired flash point parameters and meet the other requirements," like octane levels, the inventors write in their patent.
The distillate compositions of different cuts are analyzed using gas chromatography GC-20144 Shimadzu) with TCD to analyze the composition of the distillate samples.
Beside the conventional configuration, the model also includes different alternative flow-patterns for the distillate and the vapor streams.
Two aromatics-rich distillates R1 and R2 with different properties are derived from naphthenic vacuum gas oil.
Two aromatics-rich distillates R1 and R2 with different properties from naphthenic base vacuum gas oil were used for preparing mesophase pitch through high-pressure thermal treatment.
In practice when there are multiple distillate fractions, each of the distillate exit points are located at different heights on a fractionating column.
The products obtained in the reboiler and as distillate product are analyzed using different methods.
The product purity obtained is comparable due to different operating times; however, the quantity of distillate collected in multi-stage operation is higher than in single-stage operation.
