Mark J Simpson

US Patent:

57628025, Jun 9, 1998

Filed:

May 1, 1997

Appl. No.:

8/848933

Inventors:

Richard Van Court Carr - Allentown PA
Mark Shedrick Simpson - Germansville PA

Assignee:

Air Products and Chemicals, Inc. - Allentown PA

International Classification:

C02F 172

US Classification:

210626

Abstract:

A process for removing nitrocresols in a crude aqueous alkaline dinitrotoluene wash stream derived by nitration of toluene using a mixed acid technique followed by treatment with aqueous alkaline material in which the crude aqueous alkaline dinitrotoluene wash stream is mixed with a dilute oxidizing acid such as nitric acid, heated to 130. degree. to 180. degree. C. for a period of time required to reduce the nitrocresols to a level at which it does not precipitate from the mixed acidic wash stream at temperatures above about 60. degree. C. , and removing the remaining nitrocresols by conventional methods such as adsorption or activated sludge biotreatment.

US Patent:

59029102, May 11, 1999

Filed:

Sep 19, 1997

Appl. No.:

8/933706

Inventors:

William Joseph Mazzafro - Schnecksville PA
Stephen Ian Clarke - Macungie PA
Mark Shedric Simpson - Germansville PA
Richard Van Court Carr - Allentown PA

Assignee:

Air Products and Chemicals, Inc. - Allentown PA

International Classification:

C07C205/00

US Classification:

568934

Abstract:

This invention relates to an improved process for the production of dinitrotoluene wherein one is able to effectively employ a feed sulfuric acid, which is referred to as "weak acid" as the feed sulfuric acid for the nitration facility. The weak acid concentration, as feed, ranges from 86-91%, preferably 87-89% sulfuric acid by weight, to meet the total sulfuric acid requirements for the facility. This is accomplished by utilizing cocurrent processing in a mononitration zone and countercurrent nitration with respect to sulfuric acid in the dinitration zone.