Jun-2017

Oxygen for mega GTL and CTL plants - Cutting-edge multi-train solutions

Conversion processes such as coal to liquids (CTL) and gas to liquids (GTL) require vast amounts of oxygen. More than can be provided by one plant alone. Linde offers cutting-edge, multi-train solutions for exactly these kinds of applications.

Linde Engineering

Article Summary

An eight-train air separation facility in the Qatar desert is a prime example of the company’s capabilities in this area. It is located at the site of the world´s largest GTL plant to date, which went on stream after a planning and construction period spanning several years.

Highest quality at best prices
Today, the plant produces 140,000 barrels of liquid fuels per day from natural gas. The eight identical air separation units provide the oxygen required for the conversion process. Together, they generate 860,000 standard cubic metres (Nm³) of oxygen every hour from the surrounding air. Weighing 470 tonnes and rising 60 metres up into the sky, the eight coldboxes can be seen from far afield. Linde’s process experts started planning the project long before it won the contract in 2006. The company leveraged its global supplier network to guarantee the highest quality levels at the best possible prices. Key components such as the aluminium plate-fin heat exchangers and rectification columns were sourced from Linde sites in Germany and China. The coldboxes were also fully assembled as packaged units at these locations.

Difficult conditions
Preassembling the components in this way meant that Linde did not need to carry out complex assembly and construction work on-site. Which is a good thing in the desert. This kind of work would have been extremely difficult in an environment where temperatures can reach up to 50 degrees in the shade and sand storms and dust are part of daily life. As the main contractor, Linde was responsible over the entire project lifecycle for ensuring timely completion of the turnkey facility. Once the entire complex had been gradually brought on stream as planned, the company was able to officially hand over the eight air separation units after six years’ construction.

Future projects in China
The success of this mega air separation reference project in Qatar resonated among the international engineering community. In China, for example, the market for CTL plants also requires very large, highly efficient air separation units. In March 2013, Linde won a major contract for a plant near Yinchuan City, in the mid-west of China. For this project, the company was commissioned to build a six-train air separation facility with a capacity of 630,000 Nm³ of oxygen per hour. Linde built on the valuable experience it gained in Qatar to securely deliver these vast gas volumes cost effectively and reliably. Despite the remote location of the site, Linde was able to rely on its global and local network of partners to ensure a seamless execution of the project. Linde’s  engineering centres in Pullach (Germany) and Hangzhou (China) as well as its production sites in Schalchen (Germany) and Dalian (China) were all involved in the project. As a result, the six rectification coldboxes, with more than 2,000 tonnes of steel structure, were completed after only four months of work on-site.