China National Petroleum Corp started trial runs of its mega greenfield refinery complex in Guangdong on Sunday, said the nation's largest oil and gas producer by domestic annual output.

Located in Jieyang in South China's Guangdong province, the complex, which also includes a 1.2 million ton per year ethylene plant, is PetroChina's single-largest investment of its kind in China.

With a total 65.4 billion yuan ($9.57 billion) investment, the project started construction in 2018 and is part of the company's efforts in international oil and gas cooperation and refinery business upgrade, it said.

Products produced include petroleum, diesel, aviation kerosene, high density polyethylene, low density polyethylene, polypropylene, styrene and butadiene.

Environmental investment of the project is estimated to reach 7.25 billion yuan, 11 percent of the project's total investment, to ensure energy conservation and emission reduction, the company said earlier.

zhengxin@chinadaily.com.cn