Under the influence of the explosion accident which broke out in Mitsui Chemicals Otake Factory before dawn on April 22, the air separation plant of Sanyo Air Chemicals to supply Mitsui with nitrogen gas by pipeline has been suspended. Although Sanyo’s plant suffered no direct damage by the explosion, the plant operation supposedly was forced into shutdown because of the discontinued supply of steam necessary to operate the cryogenic air separation unit.

According to Mitsui Chemicals, the explosion accident occurred just after the emergency stop applied to 70% of the plant following the suspension of the facility to supply steam into Otake Factory. Therefore, at that moment Sanyo Air Chemicals located on its premises had probably been forced to stop operation due to the suspended supply of steam. The cryogenic air separation unit utilizes steam as a desorption heat source at the molecular sieve adsorption tower for the air pretreatment process.

Sanyo Air Chemicals’ plant serves as a base to supply liquid to the eastern part of Yamaguchi Prefecture as well as the Iwakuni and Otake regions. The longer the suspension continues, the more troubles will be brought to the supply of liquid to the gas users in the neighbouring area.

According to the Public Relations Dept. of Iwatani Corporation which is a shareholding company of Sanyo Air Chemicals and the major buyer of liquids from the company, a transfer supply from other liquid sources is being carried out, but if the suspension of the plant lasts long, some other measure might be worked out including arrangements for replacement with other steam generating equipment.

Sanyo Air Chemicals was established and put into operation in 1996 with the joint investment by Iwatani Corporation (60%), Daido Hoxan (30%) and Liquid Gas (10%). Since then, the joint company has been supplying nitrogen gas to Mitsui Chemicals and oxygen gas to neighbouring Daishowa Paperboard by pipeline, and also has been playing the role of a regional hub to supply liquid gases.