Ideas
Exchange Column
l&EC's features bring in lots of fan mail. Readers want information, and they pass along ideas. Ideas Exchange Column is a careful screening of this correspondence. This is not a place for praise or criticism; it is a source of technical questions and their factual answers.
Carbon Tetrachloride Manufacture DEAR M R . HARDY:
We have read your article [ I / E C 49, 57A (October 1957)], but believe that some further explanation might give us a better understanding of the relative merits of the two manufacturing processes being compared. 1. Is it correct to assume that the amount of recovered hydrochloric acid stated as 1.178 lb./lb. of carbon tetrachloride refers to anhydrous acid? Or, that the amount of 3 6 % acid actually recovered is 1.178/0.36 = 3.27 1b./lb.? 2. T h e last column of the text states that production costs due to everything except chlorine, methane, and carbon disulfide are SO.01 per pound, alternatively $0,003 per pound. T o obtain a better idea of the economy of both processes, flowsheets and detailed specifications of minor raw materials and utilities required would be helpful. 3. Would you give us more data about carbon tetrachloride production via carbon disulfide including the carbon disulfide production from methane and sulfur? ING.
ALESSANDRO
BRUNETTI
Società Agricola Industriale per La Cellulosa Italiana Torviscosa (Udine) Italy Mr. Hardy's
Answer:
You are absolutely correct in assuming that the amount of recovered hydrochloric acid stated as 1.178 per pound of carbon tetrachloride refers to anhydrous hydrochloric acid. The wording in the table does appear to be somewhat ambiguous. Unfortunately, we do not have detailed comparative costs for manufacturing carbon tetrachloride by the alternative carbon disulfide and direct chlorination procedures. T h e preparation of such a production cost analysis can be time-consuming and my schedule does not permit me to do so within the framework of the present series of articles. Thank you for your interest in my column. The series is intended to attempt to clarify some aspects of the chemical industry, not generally covered in the published literature.
If these columns really arouse chemists and chemical engineers to a growing appreciation of the economic factors underlying chemical manufacture, they will have served their purpose. Detailed presentation and analysis of individual processes are, of course, far beyond their scope.
Industrial Applications Of Titanium
DEAR MR. FRASER:
It is with great interest that we have read this article [ I / E C 49, 75A (September 1957)]. According to Circular 7711, March 1955, of the Bureau of Mines, an accident occurred in December 1953 during a corrosion test of titanium in fuming nitric acid. T h e conclusion was that the contact of titanium or its alloys with nitric acid could present risks of explosion under certain conditions—a conclusion not well defined. Considering the experience of the authors in the utilization of titanium, we would like to have their opinion on the above problem, but in particular, on the concentrations of nitric acid which can be handled without danger. J. BROCART
Le Directeur des Recherches et du Développement Establissements Kuhlmann 11, R u e de La Baume Paris 8, France Editor's Note: W. J. Weeks, Sales Engineer, has answered for Mr. Frazer. Our experience with titanium in the higher concentrations of nitric acid has led us to suggest to our customers that they restrict the use of titanium to those concentrations of nitric acid under the "fuming" level. This would include both the red and white fuming nitric acids. Several cases are given below where titanium has been used successfully in nitric acid together with the operating conditions. 1. Condenser insert was used in 60% nitric acid at 480° F. at 300p.s.i. pressure. Stainless steel failed
in 4 to 6 months ; titanium has given service approximately 2 years with no sign of attack. 2. Thermowell in dilute nitric acid plus oxides of nitrogen at 400° F. Type 316 stainless steel fails in 6 months to 1 year; titanium's estimated life is 5 years. 3. Reactor in which 3 0 % nitric acid plus nicotinic acid and methyl ethyl pyridine are used as temperatures of about 600° F. T h e corrosion rate reported was 0.3 to 6 mils per year. 4. Reactor using 2 0 % nitric acid at 400° F. and a pressure of 500 to 600 p.s.i. in the manufacture of niacine. T h e reactor is still in service; titanium corrosion samples indicated exceptionally good results. For furdier information on this subject, I suggest you contact the Titanium Metallurgical Laboratory, Battelle Memorial Institute, Columbus, Ohio. Additional information is given on corrosion of titanium in nitric acid by M. G. Fontana [ I / E C 41, 77A (August 1949)].
Construction Digest—Correction Editor's Note: We regret that a number of errors occurred in the listings of Canadian Construction Companies in the Construction Digest [ ( I / E C 50, No. 1, 57A-77A (1958)]. T h e following corrections should be made : These four listings under item 212 (p. 75A) should have been listed under item 208 (p. 70A), Canadian Industries Ltd. a. Hamilton, Ont. b. Millhaven, Ont. d. New Toronto, Ont. e. Toronto, Ont. Under item 216, the second listing (b. Montreal, Que.) should be listed under item 212, Carbide Chemicals Co. Item 237, the company at Montreal East, Que., is B. A.—Shawinigen Ltd. In item 240, the two plants listed under Surpass Petrochemicals Ltd. are actually one plant located at Scarboro, a suburb of Toronto. VOL. 5 0 , N O . 4
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APRIL 1958
93 A
