Group III base oils
The Dalian Institute of Physicochemistry claims to have developed a method to transform wax from the Fischer-Tropsch process into group III base oils with a high viscosity index. The process was successfully tested at PetroChina’s refinery in Karamay, China, officials said.
Group III Bases in China
The researchers developed the process in an attempt to help the country increase its domestic production of Group III base oils.
Located in the northern port city of Dalian, the institute operates under the direction of the Chinese Academy of Sciences. According to local reports, the institute announced on May 17 that it had developed a process that uses hydrogenation and isomerization.
The institute’s statement said the process uses Fischer-Tropsch wax made by CTL (Coal For Liquids) facilities. He said that charcoal-based Fischer-Tropsch wax produced base oils with Viscosity Index up to 150, but initially it was difficult to make oils with pour points as low as those desired by lubricant formulators.
China is one of the two largest lubricant markets in the world and domestic refineries have greatly increased their base oil production capacity in recent years.
Most of this capacity is in Group II, however, lubricant manufacturers are still largely dependent on imports for their Group III needs.
Fischer-Tropsch is a technology used to make liquid petroleum products from natural gas or coal, when used in combination with coal liquefaction. The processes were developed in the 1920s, but have only been commercialized in a few cases until recent years.
CTL installations multiply
Chinese companies have opened at least eight coal production facilities for liquids in the past 13 years, and China now has the largest number of such operations. Some of these facilities already produce Group III base oils, but they do so using technology provided by Western companies.
Wax is a by-product of CTL plants. The Dalian institute said the process it developed for base oils also produces non-aromatic solvents, drilling fluids and white oils.