| Patent application number | Description | Published |
|---|
| 20090250409 | PURIFICATION OF IONIC LIQUIDS - The invention relates to a process for purifying an ionic liquid, which comprises the steps (a) partial crystallization of the ionic liquid from its melt and (b) separation of the crystals from the residual melt. | 10-08-2009 |
| 20100022734 | PROCESS FOR SEPARATING ACRYLIC ACID PRESENT AS A MAIN CONSTITUENT AND GLYOXAL PRESENT AS A BY-PRODUCT IN A PRODUCT GAS MIXTURE OF A PARTIAL HETEROGENEOUSLY CATALYZED GAS PHASE OXIDATION OF A C3 PRECURSOR COMPOUND OF ACRYLIC ACID - A process for separating acrylic acid present as a main product and glyoxal present as a by-product in a product gas mixture of a partial gas phase oxidation of a C | 01-28-2010 |
| 20100206821 | PROCESS FOR PURIFYING REMOVAL OF A CHEMICAL TARGET COMPOUND FROM A SUSPENSION OF CRYSTALS THEREOF IN MOTHER LIQUOR - A process for purifying removal of a chemical target compound from a suspension of crystals thereof in mother liquor in a wash column with forced transport of the crystal bed from the top downward, in which crystals are removed from the lower end of the crystal bed with a rotating removal device and melted, and a portion of the crystal melt is conducted back toward the crystal bed as wash melt, the removal device being secured with a drive shaft conducted into the wash column from the bottom through an inlet having a seal, said drive shaft being driven about its longitudinal axis by a drive unit for rotation and being mounted so as to be rotatable about its longitudinal axis in more than one bearing, such that the mounting in one of the bearings absorbs the downward force acting on the drive shaft, the mounting in two or more bearings absorbs forces acting radially outward from the drive shaft, and the mounting in one bearing is additionally capable of absorbing an upward force acting on the drive shaft. | 08-19-2010 |
| 20110021789 | PROCESS FOR SEPARATING OFF FUMARIC ACID AND OTHER MINOR COMPONENTS DURING THE PRODUCTION OF MALEIC ANHYDRIDE - A process for decreasing fumaric acid deposits in the preparation of maleic anhydride by heterogeneously catalyzed oxidation of a hydrocarbon with molecular oxygen, in which the maleic anhydride is absorbed from the crude product mixture in an absorbent in an absorption column and desorbed again in a desorption column, the entirety or a portion of the absorbent depleted in maleic anhydride, for controlled precipitation of fumaric acid, being cooled and/or concentrated by evaporating a portion of the absorbent to such an extent that the difference between the concentration of fumaric acid in the recycle stream at the outlet of the desorption column under the conditions existing there and the equilibrium concentration of fumaric acid according to the solubility curve after the cooling and/or evaporation of a portion of the absorbent is greater than or equal to 250 ppm by weight, and the fumaric acid precipitated as a solid is removed completely or partly from the absorbent recycling system and the fumaric acid-depleted absorbent is recycled completely or partly to the absorption column. | 01-27-2011 |
| 20110124834 | PROCESS FOR STARTING UP A SEPARATING PROCESS FOR PURIFYING REMOVAL OF ACRYLIC ACID CRYSTALS FROM A SUSPENSION S OF CRYSTALS THEREOF IN MOTHER LIQUOR - A process for starting up a separating process for purifying removal of acrylic acid crystals from a suspension S of crystals thereof in mother liquor with a hydraulic wash column which has a crystal melt circuit including crystal melt space, and a process space and a distributor space which are separated by an end with passages connecting the two spaces, in which the crystal bed is formed for the first time by first filling the crystal melt circuit and, at least partly, the process space with an acrylic acid-comprising startup liquid whose acrylic acid crystal formation temperature is less than or equal to the temperature of the suspension S increased by 15° C., and then continuing the filling of the wash column with the suspension S and optionally with control liquor until the difference between the pressure in the crystal melt space and the pressure in the distributor space falls suddenly, the arithmetic mean of the total waste liquor flow flowing through the filters of the filter tubes of the wash column until this time, based on the area of all filters, being not more than 80 m | 05-26-2011 |
