Operation rates of major refineries in China averaged 79.1% on 12 April, touching the lowest level since October 2011, according to C1 Energy, an ICIS service in China.
The figure was down by 3.15 percentage points from two weeks earlier, mainly because of refinery turnarounds in northeast China and Shandong province.
Dalian West Pacific Petrochemical (WEPEC) shut its 10m tonne/year refinery for turnaround over 3-20 April.
Jinzhou Petrochemical's 4.5m tonnes/year crude distillate unit (CDU) went into month-long maintenance in April.
Qingdao Refining & Chemical cut its run rates because of glitch at its 220,000 tonne/year sulphur unit.
The run rates in east China were largely stable in the past two weeks as Zhenhai Refining & Chemical restarted its 8m tonne/year CDU on 5 April and shut down a 9m tonne/year CDU on 11 April.
In addition, Shanghai Petrochemical ran at higher rates with the turnarounds at some secondary conversion units complete.
Anqing Petrochemical in central China is lifting run rates after it completed turnaround.
South China's refinery run rates rose by 2 percentage points as some refiners raised their crude runs.
Major refinery run rates are expected to rebound to around 81% in the second half of April, when a combined 11.5m tonne/year refining capacity at WEPEC and Jingmen Petrochemical will come back online, market sources said.
Meanwhile, Qingdao Refining & Chemical will resume operation at its sulphur unit, while Daqing Petrochemical will shut a 2.5m tonne/year CDU for turnaround.
The refinery operation rate was an average of 35 big refineries that have a combined capacity of 7.26m bbl/day, accounting for 72% of China's total capacity of major refineries.
Lower refinery operating rates tend to increase feedstock costs for China's chemical plants, which in turn may choose to reduce their own production.