Shan Yuan Hsieh

US Patent:

7163582, Jan 16, 2007

Filed:

Sep 12, 2003

Appl. No.:

10/661169

Inventors:

Drow Lionel O'Young - West Covina CA, US
Shan Tao Hsieh - Princeton Junction NJ, US
Vaibhav Kelkar - West Covina CA, US

Assignee:

Mitsubishi Chemical Corporation - Tokyo

International Classification:

C30B 7/05

US Classification:

117 68, 117 69, 4222451, 422250

Abstract:

A system and method are provided for producing Bisphenol-A (BPA) using direct crystallization of BPA in a single crystallization stage. In one embodiment the method comprises reacting Phenol and Acetone in the presence of a catalyst to form a product solution including Bisphenol-A and Phenol; removing a part of the Phenol from the product solution if required, and providing a selective amount of solvent, so as to obtain a product solution with the desired phase equilibrium behavior; and feeding the product solution with a selective composition to a crystallization stage operated at a selected temperature, so as to recover substantially pure Bisphenol-A in crystal form.

US Patent:

20050075520, Apr 7, 2005

Filed:

Sep 17, 2003

Appl. No.:

10/665705

Inventors:

Drow O'Young - West Covina CA, US
Shan Hsieh - Princeton Junction NJ, US
Vaibhav Kelkar - West Covina CA, US

International Classification:

C07C039/16

US Classification:

568728000

Abstract:

A system and method are provided wherein the phase equilibrium of a system comprised of Phenol, Bisphenol-A and a solvent mixture comprising Acetone and Water is selectively controlled such that either crystalline Bisphenol-A, or an adduct of Bisphenol-A and Phenol is crystallized from the product solution. The present invention provides for the recovery of pure Bisphenol-A (BPA) by direct crystallization from solution.

US Patent:

6960697, Nov 1, 2005

Filed:

Mar 13, 2002

Appl. No.:

10/099227

Inventors:

Drow Lionel O'Young - West Covina CA, US
Shan Tao Hsieh - San Jose CA, US
Vaibhav Kelkar - Sunnyvale CA, US

Assignee:

Mitsubishi Chemical Corporation - Tokyo

International Classification:

C07C039/16

US Classification:

568728

Abstract:

A system and method for producing bisphenol-A (BPA) is provided. In particular, the present invention provides a system and method of producing bisphenol-A wherein the phase equilibrium behavior of a feed solution to a crystallizer is selectively controlled and adjusted to provide desired results. This provides a powerful tool, whereby certain operating conditions or variables of the bisphenol-A process can be selectively adjusted to generate desired phase equilibrium behavior. In general, bisphenol-A is produced from a reaction of phenol and acetone, forming a product solution including phenol, bisphenol-A, isomers of bisphenol-A, unreacted reactants and by-products. A solvent is provided in the product solution and the amount and composition of solvent in the product solution are selectively controlled to adjust the composition of the product solution fed to a crystallizer such that either crystalline bisphenol-A, or an adduct of bisphenol-A and phenol is crystallized from the product solution. Thus, a solvent is used to selectively control the phase behavior of the system. The solvent is a pseudo component and may be comprised of a single component or may be comprised of a solvent mixture of two or more solvents each exhibiting certain phase behavior in the system.