The fourth cold energy air separation unit (ASU) in China has started commercial operation, signalling the latest in a growing number of cold energy ASUs in the Asia-Pacific region.

Cryogenic air separation is one of a number of applications that can benefit from the recovery of the waste cold released from LNG processes.

This is application is nothing new to the Asia-Pacific region, with various ASU’s linked to LNG terminals in operation in Japan for years, and countless other examples emerging in the region – including the new ‘RAPID’ project in Malaysia which is expected to start-up in early 2019.

With the continued rise of the LNG business, and a particular boom expected in the Asia-Pacific region in the years ahead, there is clear potential for further projects capitalising on the waste cold energy generated. China is one of the countries keen to tap into this potential; there are 41 LNG receiving terminals understood to be in operation, being built, or proposed in the country.

Three such cold energy ASUs were already operating in China.

The first started commercial operation in November 2010, located in Fujian province and a joint venture between Air Products and CNOOC Energy Technology & Services Limited, a subsidiary of China National Offshore Oil Corp (CNOOC). It is capable of producing more than 600 tonnes per day (tpd) of liquid oxygen, nitrogen and argon.

The second such plant is located in Rudong in Jiangsu province in Eastern China, operated by Jiangsu Hangyang Ruihua Gases Co Ltd – a joint venture between Hangyang and Hongkong Ruihua Co Ltd – and put on-stream in August 2014. And the third plant, jointly developed by CNOOC and Sichuan Air Separation Plant Group (SASPG), was put into operation in January 2015 with a capacity of 618 tpd of liquid product. Linked to the Zhejiang Ningbo LNG Terminal (also known as the Zhejiang LNG project), Phase II of the site has already been given approval.

Now, a fourth cold energy ASU has been commissioned, jointly constructed by SASPG and Jiarui Shidai and the largest of its kind so far in China. The plant is located in Tangshan and will be operated by Tangshan Ruixin Gases Co Ltd., using the cold energy during re-gasification of the LNG at the Tangshan LNG terminal, with a rated capacity of 547 tpd of liquid oxygen, 150 tpd of liquid nitrogen, 26 tpd of liquid argon and 7 tpd of high purity liquid oxygen.

Future developments

As understood by gasworld China, the fifth such plant in China could be on-stream by the end of the year (2015).

Construction of a cold energy ASU started at the Guangdong Zhuhai LNG terminal in November 2013, with the build expected to last for 24 months. After completion, the ASU – with a total project investment of RMB 325m ($52.7m approx.) – will produce 300 tpd of liquid oxygen, 300 tpd of liquid nitrogen and 14.5 tpd of liquid argon.

Meanwhile, Yingde Gases, the rising star in the industrial gas industry in China, has expressed to gasworld China its interest in cold energy utilisation projects, but has yet to identify a commercially viable and suitable project to begin with.