The Government chlorine plant at Edgewood was ready for operation in August, 1918, but was not actually started until September 1. The plant consisted of (1) a cell house, which had a total capacity of 100 tons of chlorine per 24 hours; (2) an electric substation for supplying the current; (3) a brine building, where the salt was mixed with water and the resulting brine purified; (4) a boiler and evaporation building, for concentrating the caustic soda from the cells; (5) a caustic fusion building, for drying the caustic soda and fusing it into solid form for shipment; and (6) a liquefying plant to condense and liquefy 50 tons of chlorine per day.
With the exception of chlorine, chlorpicrin was the first war gas to be manufactured on a large scale in this country. When pure, chlorpicrin is a colorless liquid which boils at a temperature approximately of 112° C. The compound has been known since 1848. While not so poisonous as some of the other products used in gas warfare, it is, nevertheless, an active poison, and has the additional advantage of being a fair lachrymator, or tear producer.
Chlorpicrin is made by the reaction between picric acid and chlorine. The chlorine is best supplied in the form of so-called bleaching powder, which is ordinary chloride of lime. In the manufacturing process as originally carried out, free picric acid was mixed with bleaching powder held in suspension with water. Later it was found advantageous to use calcium picrate instead of picric acid.
Accordingly, the final process was as follows: The bleaching powder was creamed with water and mixed with a solution of calcium picrate in large stills holding 5,000 gallons or more. A jet of live steam was then introduced at the bottom of the still, and the reaction began at once, the rapidity depending upon the amount of steam introduced. The resulting chlorpicrin, together with a certain quantity of steam, passed out of the still and was liquefied in the condenser. The resulting mixture of chlorpicrin and water was run into tanks, where the chlorpicrin, being insoluble in water, gradually settled to the bottom and was run off and used directly in gas shell.
In developing this process the Government was assisted by the Dow Chemical Co., the Semet-Solvay Co., and the American Synthetic Color Co., of Stamford, Conn., the principal work being done by representatives of the Bureau of Mines at the Stamford plant.
AIRPLANE VIEW OF CHLORINE PLANT, EDGEWOOD ARSENAL.
CHLORINE PLANT, EDGEWOOD ARSENAL.
This is the largest single chlorine and caustic soda plant in the country. Its capacity, when entirely completed, is 100 tons of chlorine and 112 tons of fused caustic soda per day.