| Patent application number | Description | Published |
|---|
| 20090187051 | Process for the preparation of nitrobenzene by adiabatic nitration - This invention relates to a process for the continuous preparation of nitrobenzene. This process comprises the adiabatic nitration of benzene with a mixture of sulfuric acid and nitric acid, in which the sum of the concentrations in the reaction zone of the metal ions which form sparingly soluble metal sulfates is less than 900 mg/l, based on the volume of the aqueous phase which contains sulfuric acid. | 07-23-2009 |
| 20100076230 | CONTINUOUS PROCESS FOR THE MANUFACTURE OF NITROBENZENE - The invention relates to a continuous process for the manufacture of nitrobenzene. This process comprises the nitration of benzene with nitrating acid that contains at least 3.0 wt. % of nitric acid and at least 67.0 wt. % of sulfuric acid, in a reaction space in which the start temperature of the reaction is above 100.0° C. but below 102.0° C. In addition, this process requires that the benzene and the nitrating acid are dispersed in one another several times. | 03-25-2010 |
| 20130131384 | PROCESS FOR RESTORING CATALYST ACTIVITY - The present invention relates to a process for restoring the activity of spent catalysts for the hydrogenation of aromatic nitro compounds, in which a regeneration comprising at least a first burning off stage, a first washing stage, a second burning off stage and a second washing stage is carried out at periodic intervals. | 05-23-2013 |
| 20130197268 | METHOD FOR PRODUCING NITROBENZENE BY ADIABATIC NITRIDING - The invention relates to a process for the continuous production of nitrobenzene by nitration of benzene with a mixture of nitric acid and sulfuric acid under adiabatic conditions, in which unreacted benzene is separated from the crude product obtained after phase separation before washing thereof, using the adiabatic heat of reaction. | 08-01-2013 |
| 20130204043 | METHOD FOR CONTINUOUSLY PRODUCING NITROBENZENE - The present invention relates to a continuous process for the production of nitrobenzene by nitration of benzene with nitric acid or mixtures of nitric acid and sulfuric acid to give a crude nitrobenzene, washing of the crude nitrobenzene by means of at least one of each of an acid, alkaline and neutral washing, there being obtained a pre-purified nitrobenzene which, as well as containing nitrobenzene, at least contains also low boilers, optionally middle boilers as well as high boilers and salts, wherein the pre-purified nitrobenzene is purified further by separating off low boilers in a distillation apparatus by evaporation of the low boilers, and separation of nitrobenzene from the resulting further purified nitrobenzene in a distillation apparatus by partial evaporation of nitrobenzene, wherein pure nitrobenzene is removed from the distillation apparatus in gaseous form and is subsequently condensed, and wherein the non-evaporated portion of the further purified nitrobenzene is fed back into the washing at any desired point. | 08-08-2013 |
| 20130296610 | CHEMICAL REACTOR HAVING WOVEN WIRE MESH PRODUCT AS A RETAINING DEVICE FOR PARTICLES - In a chemical reactor for heterogeneously catalysed reaction of a fluid, comprising a holding device for catalyst particles and/or inert particles ( | 11-07-2013 |
| 20140131275 | PROCESS FOR PHASE SEPARATION OR EXTRACTION AND DEVICE SUITABLE THEREFOR - The present invention relates to a device for separating two immiscible phases and/or for extracting one phase with another phase (phase separation or extraction device), comprising at least one vessel for receiving the at least two phases, at least one pipe for supplying a fluid to the vessel, at least one pipe for discharging a fluid from the vessel, and at least one arrangement comprising a transparent disk for observing the separation operation or the extraction operation, wherein at least the side of the transparent disk that faces the phases to be separated or extracted consists of sapphire (sapphire glass) or mica ( mica disk), and to the use of such a device in the preparation of di- and polyamines of the diphenylmethane series. | 05-15-2014 |
| 20150073180 | METHOD FOR CONTINUOUS PRODUCTION OF NITROBENZENE - The invention relates to a method for producing nitrobenzene, in which crude nitrobenzene is first produced by nitrating benzene and said crude nitrobenzene is then washed in succession in at least one acid wash, in at least one alkaline wash and in at least one neutral wash, at least one additional wash with an aqueous solution of a potassium salt being interposed between the last alkaline wash and the first neutral wash. | 03-12-2015 |
| 20150080611 | METHOD FOR STARTING A REACTION DURING THE PRODUCTION OF AROMATIC AMINES FROM NITROAROMATICS - The present invention relates to a method of producing aromatic amines by hydrogenation of aromatic nitro compounds. This method comprises the steps:
| 03-19-2015 |
| 20150087862 | METHOD FOR STOPPING A REACTION DURING THE PRODUCTION OF AROMATIC AMINES FROM NITROAROMATICS - The present invention relates to A method for producing aromatic amines by the hydrogenation of aromatic nitro compounds. This method comprises:
| 03-26-2015 |
