The chlorpicrin plant at Edgewood went into entire operation on June 14, 1918. Up to the signing of the armistice this plant had produced 2,320,000 pounds of chlorpicrin.
Phosgene was one of the deadliest gases employed in the war. Numerous other gases were used to annoy the enemy and force the wearing of masks, but phosgene was a killer employed to produce as many casualties as possible. The gas did not persist long in the air or on the ground after the shell had exploded, so that it was an ideal chemical for use in an attack. The gas would clear away by the time the troops following reached the place of gas concentration.
Phosgene at ordinary temperatures is a colorless gas, but it condenses to a liquid at 8° C. It is formed by the combination of two gases, chlorine and carbon monoxide, in the presence of a catalyzer. The reaction is best conducted in iron boxes lined with lead and filled with charcoal of proper quality, into which boxes a stream of the reacting gases, mixed in proper proportions, is introduced. The reaction creates heat, and means must usually be taken to keep the reaction boxes cooled. The resulting phosgene is condensed to a liquid by passing the gas through a condenser which is surrounded by brine kept cold by refrigeration. The liquid is then stored in strong steel containers or run directly into Livens drums or artillery shell.
Prior to 1917, the Oldbury Electro-Chemical Co., of Niagara Falls, N. Y., had set up a small experimental phosgene plant in the hope that the experiments might lead to the commercial utilization of carbon monoxide which was obtained by this company as a by-product in the manufacture of phosphorus. When we entered the war the company had developed its process to such efficiency as to warrant the construction of a large phosgene plant, and the Government entered into a contract with the company for the creation of facilities with a capacity of 10 tons of phosgene per day. Also, because of the great importance of phosgene in warfare, it was decided at the same time to build a Government phosgene plant at Edgewood. A little later the Government financed a phosgene plant at the factory of Frank Hemingway (Inc.), at Bound Brook, N. J.
The total output of the original small experimental plant at Niagara Falls, which was later leased by the United States, was 83,070 pounds of phosgene, of which 24,800 pounds were shipped overseas. The contract with the Oldbury Chemical Co. for its main phosgene plant was signed on January 15, 1918. Production here began on August 5 and by August 20 had reached a daily average of 5 tons. On November 1 the average daily production was 7 tons. The total quantity produced at this plant was 435 tons. The plant loaded 18,768 Livens drums with phosgene, each drum holding about 30 pounds. This plant was operated by enlisted men.
The contract with Frank Hemingway (Inc.) called for a factory producing 5 tons of phosgene per day by a secret process controlled by the company. The construction of the plant was begun on February 2, 1918, and phosgene was first manufactured on May 17. This concern reached its maximum of 5 tons per day by August 1, and produced in all 205 tons of phosgene.
Construction of the phosgene plant at Edgewood was begun on March 1, 1918. The plant consisted of four catalyzer buildings, each building having four units, each unit possessing a projected capacity of 5 tons of phosgene per day. The total capacity, therefore, was designed to be 80 tons per day. The carbon monoxide used in the process was produced by passing a mixture of oxygen and carbon dioxide over heated coke in a gas producer, the oxygen being supplied by a Claude machine with a capacity of 100,000 cubic feet of oxygen every 24 hours. The chlorine used came partly from the Edgewood chlorine plant and partly from outside sources.
The actual production of phosgene at Edgewood began on July 5, 1918, and worked up to an output of 20 tons per day by the date of the armistice. The total production of phosgene at Edgewood was 935 tons. The total output of phosgene from all three plants, Edgewood and the Bound Brook and Niagara Falls operations, at the date of the armistice was 35 tons per day; and this was increasing to reach 95 tons per day by May 1, 1919. The total phosgene produced by all the plants before the armistice was 1,616 tons.
The Germans, in spite of their attainments in chemistry, were never able to improve their clumsy and expensive methods of producing mustard gas. The best reports we have show that at the time the fighting ended, all of Germany's chemical warfare facilities could not produce more than 6 tons of mustard per day. The United States alone had ten times that capacity on the same date, while France and England both reached a heavy output. So concerned was the German high command because of the fact that Germany was being outdistanced in the production of mustard gas that the ablest spy of the German Empire was sent into France in October, 1918, to find out the French method of making mustard. One of the Chemical Warfare officers who accompanied our forces into German territory reported that the Germans had decided to adopt the American method of making mustard gas and to stop their former process.
Mustard gas was by no means a child of the great war, having been prepared in experimental quantities since 1886. It is a colorless, slightly oily liquid, boiling at 220° C. with some decomposition. When perfectly pure it freezes at 14° C.; but, since it usually contains small percentages of impurities, it usually remains liquid at 0° C, or even below that. In chemistry the substance is known as dichlorethyl sulphide.