| Patent application number | Description | Published |
|---|
| 20080200734 | CRYSTALLIZATION PROCESSES FOR PRODUCING BISPHENOLS - Processes for producing bisphenols (e.g., bisphenol A (BPA)) having a purity greater than 99.7% are described, such processes including reacting a phenol and acetone in the presence of an acidic catalyst to form a product mixture comprising a bisphenol; removing at least a portion of the bisphenol from the product mixture in the form of a bisphenol/phenol adduct by crystallization, filtration and washing to provide bisphenol/phenol adduct crystals; and removing at least a portion of the phenol from the bisphenol/phenol adduct crystals to provide the bisphenol having a purity of more than 99.7%; wherein the crystallization comprises continuous suspension crystallization and is carried out in at least three crystallization devices arranged such that the product mixture is first cooled in a first stage of the crystallization to a temperature of 50 to 70° C. in a first crystallization device and a second crystallization device connected in parallel, and subsequently cooled in a second stage of the crystallization to a temperature of 40 to 50° C. in a third crystallization device connected downstream in series to the first and second crystallization devices, and wherein a total dwell time of the product mixture in the crystallization is more than 4 hours. | 08-21-2008 |
| 20080281130 | PROCESS FOR PRODUCING BISPHENOL A WITH AN EXTENDED SERVICE LIFE IN THE CRYSTALLISATION - The invention describes a process for producing bisphenol with a content of less than 15 wt. % of phenol, wherein a suspension crystallisation of a product mixture containing bisphenol A, minor components and phenol is performed in a crystalliser, the product mixture being pumped through a heat exchanger. Due to deposition (fouling, i.e. crystallisation and deposition on the surface of the heat exchangers) in the heat exchanger, the pressure difference increases from 0.5 to 3 bar across the heat exchanger. The resulting reduced flow rate, which would lead to increased fouling in the crystalliser, is offset by continuously increasing the speed of the pump, the pump speed being regulated in such a way that the current consumption of the pump is maintained such that it fluctuates by a maximum of 5%. | 11-13-2008 |
| 20080306174 | METHOD FOR DECANTING PRECONDITIONED ION-EXCHANGE RESIN SUSPENSIONS - A process for the storage or transportation of pretreated, conditioned ion exchangers as catalysts for chemical reactions is disclosed. The preconditioned ion-exchange resin is kept as preconditioned ion-exchange resin suspension in a storage or transporting container. The container with the preconditioned ion-exchange resin suspension is transported to either a storage site for storage or to a reactor for transfer of the resin to the reactor. | 12-11-2008 |
| 20090143619 | PROCESS FOR THE PRODUCTION OF PHOSGENE WITH REDUCED CO EMISSION - The application relates to a process for the continuous production of phosgene from chlorine and CO with reduction of the carbon monoxide emission (CO emission). | 06-04-2009 |
| 20100305365 | REGENERATION OF ACIDIC ION EXCHANGERS - The invention relates to a method for regenerating acidic cation exchangers, which are used as catalysts in the reaction of phenols with aldehydes or ketones to give bisphenols, in particular to give bisphenol A, with acids, with the proviso that, in the method according to the invention, these cation exchangers experience very little mechanical damage due to swelling processes during the regeneration process. | 12-02-2010 |
