In the past, acetylene was used in the manufacture of several large-volume derivatives. Feedstock replacement and or more economical processes not using acetylene have been major drivers for a decline in demand. The availability and cost of competing replacement raw materials and domestic demand vary significantly by region.
Acetylene is produced from calcium carbide or hydrocarbon feedstocks. In 2007, 73% of acetylene produced for chemical use in the United States was derived from hydrocarbons; the remainder was from ethylene coproduct. In Western Europe, hydrocarbons are also the primary feedstock, while in China, Japan, Europe and the CIS, acetylene is produced primarily from calcium carbide.
The rise in crude oil pricing has revitalized chemical consumption of acetylene in China. Acetylene demand for vinyl chloride monomer has grown 15.9% per year since 1997 and has spurred future coal–calcium carbide–acetylene–based expansions over the next five years. In an effort to better manage this rapid growth, the Chinese government decided to consolidate the industry including the closure of smaller, higher-polluting producers by 2011. As a result of these changes, actual acetylene demand growth will be lower than previous years.
In less developed countries where coal and natural gas are in surplus and as crude prices remain high, the economics for this technology remain competitive.
The following pie chart shows consumption of acetylene by major region:
Since compression and transportation of acetylene is not practical for large-scale chemical use, almost all acetylene for chemical synthesis is consumed at or near the production site. Of the total acetylene capacity for the four major regions, most acetylene is captively consumed by the producers. For industrial uses (primarily cutting and welding gas), acetylene is generated locally from calcium carbide and compressed into cylinders so that it can be transported to a use site; some industrial gas producers (Praxair and Air Liquide in North America) also repackage acetylene that is delivered via pipeline from neighboring ethylene/acetylene producers. No significant amounts of acetylene are imported or exported; therefore consumption in a geographic region is approximately equal to production.
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