Linde Group's Air Separation Facility, South Korea

Linde Korea, the Korean subsidiary of the Linde Group, officially inaugurated a new industrial gas plant in the district of Giheung, Yongin, in October 2011. The plant comprises an air separation unit (ASU). It is the second such facility built by the company in Giheung.

The ASU will produce nitrogen, oxygen and argon of high purity to customers in diverse manufacturing industries. These industrial gases are used in a number of industrial applications including steel, semiconductor, glass, automotive, petrochemical, electronics and shipbuilding.

The project involved an investment of approximately KRW206bn ($180m or €130m). It is the single largest investment made by Linde to date in the country.

Background to the industrial gas plant

"The plant was chosen to be built in South Korea as Asia is a key market for the Linde Group."

The plant was chosen to be built in South Korea as Asia is a key market for the Linde Group.

Industrial growth and economic progress of South Korea in the past few years has stimulated growth in a number of industries which consume gases. There has been a surge in the demand for industrial gases due to the industrial growth.

The company signed a memorandum of understanding (MoU) with the Gyeonggi province and Yongin in 2008 to build the company's second ASU in the province.

Type of technology used at Linde Korea's facility

The most common technology used in air separation for the production of high purity industrial gases is cryogenic rectification.

Rectification is similar to distillation separation, a process which enables separation of the components of a mixture. The process enables the separation of the components with high purity even if the boiling points of the components are very close.

Process technology at the South Korean air separation facility

Cryogenic air separation processes can be used to produce both gaseous and liquid forms of ultra high purity oxygen, nitrogen and argon.

The process begins with internal compression of ambient air by a multistage turbo compressor at a pressure of about six bar. The mechanical air filter at the inlet of the compressor removes any dust particles present in the air.

"The project involved an investment of approximately KRW206bn ($180m or €130m)."

The process air is cooled by bringing it in ro contact with a water cooler. Any soluble air impurities are removed. The carbon dioxide, water vapour and hydrocarbons are removed by molecular sieve adsorbers that are periodically loaded.

The air is further cooled to liquefaction temperature with the help of heat exchangers. It is then compressed by an air booster compressor. The compressed cold air is expanded in a turbine. A side stream of the boosted air is liquefied in a liquid separator. The stream is further compressed by booster compressors, and expanded and cold produced in a turbine.

The pumped oxygen and nitrogen are evaporated and warmed to ambient temperatures using high pressure heat exchangers.

The cooled and liquefied air in the pressure column is pre-separated into oxygen enriched liquid and nitrogen gas. The liquid containing oxygen remains in the column sump while the nitrogen gas rises to the column top. The nitrogen gas is liquefied in a condenser. The oxygen remains boiling in the sump of the low pressure column.

The process is repeated, wherein the oxygen-enriched liquid within the low pressure column is separated in a further low pressure column while nitrogen waste gas comes up to the top of that column. The process ends when all the nitrogen gas in the liquid is rectified.

Argon is also produced by a similar process using cryogenic rectification.

Companies benefitting from the plant based in Giheung, Yongin

Semiconductor and electronics industries, for which Korea is regarded as a hub, are expected to benefit the most as the plant will offer cost-effective supply of gases to the companies in these industries.

Ultra high purity nitrogen and other industrial gases have a number of applications in electronics and semiconductor industries. Linde expects its major customers LG and Samsung Electronics, who are operating in these industries, to benefit from the opening of the new plant.

The completion of the plant ensures reliable supply of the critical industrial gases for these companies, for stable and uninterrupted production at their manufacturing sites.