Process for storage and transport of toluenediamine
AssigneeAir Products and Chemicals, Inc.
InventorsRichard Van Court Carr, Andrew J. Casale
Life of this patent
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Abstract
This invention relates to an improved process for storing and transporting toluenediamine, particularly for long term storage or storage in large containers, e.g., shipboard containers. The improvement in the process resides in substantially reducing the melting or freezing point of anhydrous toluenediamine obtained by the fractional distillation of a reaction product generated by the hydrogenation of dinitrotoluene. Such melting point reduction is accomplished by adding water in an amount of from 5 to 15% by weight of the toluenediamine and mixing therein for storage and transport. Preferably the level of water introduced to the anhydrous toluenediamine is from about 7 to 10% by weight.
Claims6
An improved process for preparing meta-toluenediamines for storage and/or transportation in large containers, the improvement which comprises:
- adding a demineralized water in an amount of from 5 to 15% by weight to a substantially anhydrous meta-toluenediamine isomer mixture obtained by the fractional distillation of a reaction product generated by the hydrogenation of dinitrotoluene at a temperature of at least 200.degree. F. and mixing the water therein for substantially reducing the freezing point of said substantially anhydrous meta-toluenediamine isomer mixture, and adjusting the final temperature such that the product is at a temperature below the bubble point.
In a process for producing a meta-toluenediamine mixture wherein toluene is contacted with nitric acid in the presence of sulfuric acid under conditions for producing a reaction product containing primarily a 2,4- and 2,6-dinitrotoluene isomer mixture, the dinitrotoluene recovered and then contacted with hydrogen in the presence of a hydrogenation catalyst, the resulting reaction product containing 2,4- and 2,6-toluenediamine distilled in a column under reduced pressure and elevated temperature to remove any lights, water, toluidine, ortho-toluenediamine and byproducts, the substantially anhydrous meta-toluenediamine isomer mixture recovered from the bottom of the column and passed to a product cooler where the temperature is reduced to about 200.degree.-250.degree. F. and the pressure elevated to at least atmospheric, the improvement for preparing the resulting meta-toluenediamine isomer mixture for storage and/or transport which comprises:
- adding a deionized water in an amount of from 5 to 15% by weight to said substantially anhydrous meta-toluenediamine isomer mixture at a temperature of at least 220.degree. F.,
- mixing the water with said substantially anhydrous meta-toluenediamine isomer mixture;
- and,
- adjusting the final temperature such that the product is at a temperature below the bubble point.
Dependencies are inferred from the claim text.