Method for producing phenol-BPA adduct crystals
US8702863B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 1, 2013 |
| Grant date | Apr 22, 2014 |
| Priority date | — |
| Expiry date | Mar 1, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1024
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for the evaporative production of phenol-BPA adduct crystals in a crystallizer is provided. First, a supersaturated BPA solution is introduced into a crystallizer that includes a cylindrical vessel and a concentrically-disposed draft tube that defines an annular space between the vessel and tube. Next, the BPA solution is circulated through the draft tube and annular space while a coolant is uniformly distributed in the circulating flow by radially injecting a volatile hydrocarbon compound at between about 30% and 60% of a radial extent of the annular space of to form a BPA mixture. Phenol-BPA adduct crystals are produced in the vessel by evaporating the volatile hydrocarbon compound out of the BPA mixture. The method provides a consistent and uniform concentration of coolant across the surface of the boiling zone that prevents or at least reduces unwanted crystal nucleation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.