Bisphenol production
AssigneeBayer Aktiengesellschaft
InventorsFrieder Heydenreich, Michael Prein, Michael Bödiger, Rainer Neumann, Gerhard Fennhoff, Johan Vaes
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Abstract
A process for the production of 2,2-bis(4-hydroxyphenyl)propane (BPA) is disclosed. The process that entails reacting acetone with phenol in the presence of cross-linked sulfonated polystyrene resins is characterised in that BPA is separated from the reaction solution downstream of the reaction unit by means of a multi-stage vacuum distillation and a subsequent single- or multi-stage layer crystallisation. The by-product stream with accumulated by-products is returned downstream of the reaction unit.
Claims12
A process of preparing 2,2-bis-(4-hydroxyphenyl)propane comprising:
- (a) providing an apparatus comprising in sequence,
- (i) a reaction unit containing cross-linked sulfonated polystyrene resins,
- (ii) a first distillation column that is downstream from and in fluid communication with said reaction unit,
- (iii) a second distillation column that is downstream from and in fluid communication with said first distillation column, and
- (iv) a crystallization unit that is downstream from and in fluid communication with said second distillation column, said crystallization unit comprising a by-product conduit that is in fluid communication with said second distillation column;
- (b) introducing and reacting phenol and acetone into and within said reaction unit, thereby forming a reaction unit product stream comprising 2,2-bis-(4-hydroxyphenyl)propane, phenol, acetone and by-products;
- (c) introducing the reaction unit product stream into said first distillation column, thereby forming a first distillation column product stream comprising 2,2-bis-(4-hydroxyphenyl)propane;
- (d) introducing the first distillation column product stream into said second distillation column, thereby forming a second distillation column product stream comprising 2,2-bis-(4-hydroxyphenyl)propane;
- (e) introducing the second distillation column product stream into said crystallization unit, thereby forming a crystallization unit product stream comprising purified 2,2-bis-(4-hydroxyphenyl)propane, and a by-product stream comprising by-products;
- and
- (f) introducing at least a portion of the by-product stream from said crystallization unit into said second distillation column by means of said by-product conduit.
An apparatus for preparing purified 2,2-bis-(4-hydroxyphenyl)propane comprising in sequence:
- (i) a reaction unit containing cross-linked sulfonated polystyrene resins;
- (ii) a first distillation column that is downstream from and in fluid communication with said reaction unit;
- (iii) a second distillation column that is downstream from and in fluid communication with said first distillation column;
- and
- (iv) a crystallization unit that is downstream from and in fluid communication with said second distillation column, said crystallization unit comprising a by-product conduit that is in fluid communication with said second distillation column.
Dependencies are inferred from the claim text.