Back vacuum distillation unit

Regardless, I tried culling ihe steam back to 5,000 Ib/hr to see how much the vacuum distillate rate would increase. Surprisingly, the flow of vacuum distillate remained constant. The only notable result on the crude unit was a drop in flow of wet gas from the reflux drum. The 3,000 Ib/hr cut in the bottom s stripping steam had unloaded the overhead condenser. This caused the reflux drum temperature to drop and hence reduced the flow of wet gas to the off-gas compressor. 

Description Extractive distillation is used to separate close-boiling components using a solvent that alters the volatility between the components. An ED Sulfolane unit consists of two primary columns they are the ED column and the solvent recovery column. Aromatic feed is preheated with lean solvent and enters a central stage of the ED column (1). The lean solvent is introduced near the top of the ED column. Nonaromatics are separated from the top of this column and sent to storage. The ED column bottoms contain solvent and highly purified aromatics that are sent to the solvent recovery column (2). In this column, aromatics are separated from solvent under vacuum with steam stripping. The overhead aromatics product is sent to the BT fractionation section. Lean solvent is separated from the bottom of the column and recirculated back to the ED column. 

The devolatilizer (7) is held under a very high vacuum to remove unreacted monomer and solvent from the polymer melt. The monomer is distilled in the styrene recovery unit (8) and recycled back to the prepolymizer. The polymer melt is then pumped through a die head (9) to form strands, a waterbath (10) to cool the strands, a pelletizer (11) to form pellets and is screened to remove large pellets and fines. The resultant product is air-conveyed to bulk storage and packaging facilities. 

My own technical experience has pretty much followed this history of distillation simulation. My practical experience started back in a high-school chemistry class in which we performed batch distillations. Next came an exposure to some distillation theory and running a pilot-scale batch distillation column as an undergraduate at Penn State, learning from Arthur Rose and Black Mike Cannon. Then, there were five years of industrial experience in Exxon refineries as a technical service engineer on pipestills, vacuum columns, light-ends units, and alkylation units, all of which used distillation extensively. 

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