Then in 1883, Carl Friedrich Claus, working in London, patented a process called the Claus process, that allowed recovering sulfur from hydrogen sulfide gas. By 1887, Alexander Chance and C.F. Chance modified his process to process sulfur from the left over waste of the Leblanc process (which was used to manufacture soda ash (sodium carbonate), useful for glass, textile and soap industries). Until then, the waste product of the Leblanc process, which is calcium sulfide, was simply thrown into heaps outside the plant. The Claus-Chance process first converts the calcium sulfide to hydrogen sulfide, using water and carbon dioxide, and then extracts the sulfur from the hydrogen sulfide gas using the Claus process. Therefore, all those heaps of waste calcium sulfide that were thrown out earlier, could be used to extract the sulfur from them.
A pile of Sulfur produced by the Claus process in Vancouver, Canada. Click on the image to enlarge.
Image licensed under Creative Commons Share Alike 1.0 License by LeonardG.
Using the Claus-Chance process, England became the second largest sulfur producer in the world by the early 1890s.
The British also attempted to form a cartel to control the Sicilian industry, almost 55 years after the attempt made by the French Company TAC. The Anglo-Sicilian Sulfur Company (ASSC) was formed in 1896, which gained control of about 2/3rd of Sicily's export. In particular, they made some huge sales in the American marketplace, shipping it to many well known companies in the US.
However, there was danger to the Anglo-Sicilian Sulfur Company from an American invention that we will study about in our next post: the Frasch process. Sicily was exporting over 177,000 tons to the American market in 1902, 106,000 tons in 1904, and two years later, it dropped to 7000 tons thanks to the new process invented in America! In fact, in 1906 Sicily was no longer the global dominant producer of sulfur, being replaced by sulfur produced in Louisiana and Texas, which was cheaper and purer, and the Anglo-Sicilian Sulfur Company was out of business a couple of years later.
However, while the Claus-Chance process went into decline, the Claus process did not go away entirely. In fact, it is still around today and is the dominant method of producing sulfur today, as there is plenty of hydrogen sulfide gas from other sources, especially from oil and natural gas fields and from crude oil refineries.
We will study the Frasch process in our next post.