Thermal stabilization of chlorobenzenes
AssigneeE. I. Du Pont de Nemours and Company
InventorWalter Mahler
Life of this patent
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Abstract
Chlorobenzenes with 2 to 5 chlorine substituents particularly trichlorobenzenes, can be used in a heat transfer method, particularly when contained in steel or aluminum vessels and at temperatures in the range of 260-450.degree. C, by contact with a thermal stabilizing amount of a solid acid acceptor selected from A. a carbonate, phosphate, borate, or molybdate of an alkali metal or an alkaline earth metal or B. an oxide of zinc, cadmium or an alkaline earth metal.
Claims17
A method of heat transfer wherein the least one chlorobenzene of the formula
- C.sub.6 H.sub.6-x Cl.sub.x
- where x is 2 to 5
- is cycled through a thermal gradient including temperatures above about 260.degree. C, the improvement which comprises contacting said chlorobenzene with a thermal stabilizing amount of a solid acid acceptor selected from
- a. a carbonate, phosphate, borate or molybdate of a Group I-A alkali metal of atomic number 3-55 of a Group II-A alkaline earth metal of atomic number 12-56, or
- b. an oxide of a Group II-A metal of atomic number 12-56 or a Group II-B metal of atomic number 30-48.
In a method of heat transfer wherein at least one chlorobenzene selected from the class consisting of dichlorobenzene and trichlorobenzene is cycled through a thermal gradient including temperatures above about 260.degree. C., the improvement which comprises contacting said chlorobenzene with a thermal stabilizing amount of a solid acid acceptor selected from the class consisting of sodium borate and Na.sub.3 PO.sub.4, wherein said chlorobenzene is in contact with ferritic steel, austenitic steel or aluminum, and wherein said chlorobenzene is contacted with said acid acceptor at a temperature in the range of about 260.degree. C to 450.degree. C.
Dependencies are inferred from the claim text.