Super-fractionation

Inside-out Boston (70) Wide variety of boiling-point ranges, columns and Specifications Ideal to nonideal systems Super fractionators, petrochemical, chemical columns Wide variety, multiple purity, allows fur broad mix including least squares solution when overspecified... 

Sulzer/ABB Lummus Global Butene-1 Mixed C4 hydrocarbons Super fractionation to produce high purity (99+%) butene-1 5 1998... 

Techniqttes for the separation of eth benzene in aromatic Cg cuts, particularly super-fractionation and possibly adsorption on molecular sieves, have been covered by spedbe analyses (see Sections 4.Z3 and 4.3.2.1). Thus, only chemical methods need to be examined, especially s>nthesis, which is a decisive hictor at the industrial level, and which involves the alkylation of benzene with ethylene. 

Description The Snamprogetti technology for butene-1 is based on proprietary binary interaction parameters that are specifically optimized after experimental work to minimize investment cost and utilities consumption. The plant is a super-fractionation unit composed of two fractionation towers provided with traditional trays. 

Ethylbenzene, separated from the other isomers by super-fractionation for use in making styrene or as a Rule 66 solvent, has a flash point of 21 C. 

The concept of the super-fractionation separation stage in distillation is a key concept in process ojjerations and chemical engineering. Yet I have never seen this idea discussed in any... 

The concept of a super-fractionation tray is important when separating products, if either the top or bottom product consists of a multi-component mixture. For example, if we are fractionating only a mixture of propane and isobutane, the super-fractionation concept would not be significant. However, if the overhead product consisted of a mixture of ethane, propane, and isobutane (i.e., C2S, C3S, and C4S) and the overhead condenser was a partial condenser (see Fig. 49.1), then the partial condenser would serve as a super-fractionation stage. The partial condenser would contribute far more to fractionation than any of the other stages in the upper portion of the distillation tower. 

Figure 49.1 A partial condenser serves as a super-fractionation stage.

Any time heat is removed from a fractionation stage above a tower s feed point, that stage becomes a super-fractionation stage. To prove my point, note the temperatures shown in Fig. 49.4 ... 

Overflowing reflux from the hot drum into the cold drum destroyed the efficiency of the super-fractionation stage represented by the partial condenser. To restore this lost fractionation, I had the panel board operator lower the reflux drum level to 60 percent by increasing the tower top reflux rate. This time I waited a few hours before pulling my naphtha product sample. Analysis then showed there was now only 7 percent jet fuel in the naphtha product. Finally, real victory ... 

Side reboilers and intercoolers also function as super-fractionation separation stages. They are just a subcase of once-through thermosyphon reboilers and partial overhead condensers. 

Super-fractionation Effect of partial condenser or once-through reboiler on fractionation. 

---