Distillation: processes – separatory – With chemical reaction – Including step of adding catalyst or reacting material
Reexamination Certificate
2006-09-19
2006-09-19
Manoharan, Virginia (Department: 1764)
Distillation: processes, separatory
With chemical reaction
Including step of adding catalyst or reacting material
C203S071000, C203S100000, C560S347000, C560S352000, C560S359000
Reexamination Certificate
active
07108770
ABSTRACT:
Toluene diisocyanate is recovered from a crude distillation feed containing less than 2% by weight of phosgene by(a) fractionating the crude distillation feed containing less than 2% by weight of phosgene to remove the solvent and optionally the reaction residues to produce a crude toluene diisocyanate feed containing less than 20% by weight of solvent and(b) separating the crude toluene diisocyanate feed containing less than 20% by weight of solvent in a divided-wall distillation column into four product fractions P1–P4. P1 is a vapor phase low-boiler and solvent-enriched gas stream, P2 is a low-boiler and solvent-enriched product, P3 is a high boiler-enriched bottoms product containing toluene diisocyanate and P4 is a toluene diisocyanate product stream lean in low-boilers, high-boilers and reaction residues.
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Brady, Jr. Bill
Grün Marcus Paul
Keggenhoff Berthold
Schal Hans-Peter
Verkerk Kai
Bayer Aktiengesellschaft
Manoharan Virginia
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