| Patent Number |
Title Of Patent |
Date Issued |
| 7345173 |
Work-up of the mother liquor obtained in the preparation of high-purity triethylenediamine |
March 18, 2008 |
| In a process for the purification of triethylenediamine (TEDA) in which TEDA is vaporized and the gaseous TEDA is passed into a liquid solvent and is subsequently crystallized from this, the mother liquor obtained after the TEDA has been crystallized is extracted with an extractant w |
| 7342139 |
Method for producing highly concentrated formaldehyde solution |
March 11, 2008 |
| A process for preparing a high-concentration formaldehyde solution by removing water from a lower-concentration formaldehyde solution having a formaldehyde content of from 5 to 50% by weight, in which the lower-concentration formaldehyde solution is fed to a preheater and heated in t |
| 7151177 |
Process for the preparation of highly pure triethylene diamine |
December 19, 2006 |
| Highly pure triethylenediamine is obtained by a process in which triethylenediamine is freed from high boilers and then the triethylenediamine is vaporized from the mixture thus obtained and is passed into a liquid solvent. The process makes it possible in particular to obtain highly |
| 7132538 |
Isolation of high-purity triethylenediamine (TEDA) by distillation |
November 7, 2006 |
| Process for purifying triethylenediamine (TEDA) by disillation, in which the fractionation is carried out in a dividing wall column. |
| 7029557 |
Method for producing an aqueous hydroxylamine solution devoid of salt |
April 18, 2006 |
| The invention relates to a method for producing a highly pure, aqueous hydroxylamine solution by distilling an aqueous solution, devoid of salt, of a hydroxyl ammonium salt in a plate column comprising at least two mechanical plates. Said method is characterised in that packing bodies |
| 6942762 |
Method for the production of a salt-free aqueous hydroxylamine solution |
September 13, 2005 |
| A process for preparing a salt-free aqueous hydroxylamine solution by distilling an aqueous solution of a hydroxylammonium salt and a base in a tray column having at least two mechanical trays, wherein random or structured packings are located above at least one tray of the tray column |
| 6617047 |
Method for coating apparatuses and parts of apparatuses used in chemical manufacturing |
September 9, 2003 |
| The present invention relates to a process for coating apparatuses and apparatus parts for chemical plant construction--which are taken to mean, for example, apparatus, tank and reactor walls, discharge devices, valves, pumps, filters, compressors, centrifuges, columns, dryers, comminuti |
| 6552194 |
Process for the preparation of pure triethylenediamine (TEDA) |
April 22, 2003 |
| The invention relates to the preparation of pure triethylenediamine (TEDA) by evaporating TEDA from the mixture comprising a solvent or diluent, where the solvent or diluent has a boiling point at atmospheric pressure in the range from 175 to 250.degree. C., passing the vapor-form TEDA i |
