Trunk line of the world\'s longest natural gas pipeline, or main line of China\'s second west-to-east natural gas pipeline, went into operation on Thursday. The pipeline, connecting central Asia and China, will deliver natural gas from Turkmenistan to as far afield as Shanghai in eastern China and Guangzhou and Hong Kong in southern China. Once completed, the entire pipeline will be about 8,700 km long. The pipeline will have one trunk and eight branches. Three branches have been completed and the other five will be finished next year. The pipeline starts in Huoerguosi on the China-Kazakhstan border, 670 km northwest of Urumqi, capital of Xinjiang Uygur Autonomous Region. The annual natural gas transportation capacity of the pipeline is expected to be 30 billion cubic meters. It is designed to provide stable gas supply for at least 30 years. Guo Xiaofang, a primary school teacher and citizen in Guangzhou, hopes she can soon use natural gas from the pipeline instead of liquid gas. \"Natural gas is clean and safe, more convenient than liquid gas,\" Guo said. Liao Yongyuan, deputy general manager of China National Petroleum Corporation (CNPC), said the project would optimize the country\'s energy consumption structure. As of May 28 this year, the already finished lines had delivered 10 billion cubic meters of natural gas to about 18 provincial regions and about 100 million people, Liao said. The pipeline will benefit about 500 million people altogether, he said. It is expected to help ease strained natural gas supply in the Pearl River Delta and the Yangtze River Delta. And it is planned to be connected with natural gas lines already in use, resulting in a network totaling 40,000 km of gas pipelines. The pipeline will also be connected with the country\'s key natural gas bases to ensure about 15 billion cubic meters of emergency supply resources, said Xu Yongfa, director of the CNPC Economics and Technology Research Institute. About 270 cities should have access to natural gas this year and about 95 percent of major cities will use natural gas by 2050, according to analysts. Zhou Dadi, deputy-director of China Energy Research Society (CERS), said China\'s natural gas consumption is below Asia\'s average and the second west-to-east natural gas pipeline would help improve the country\'s energy consumption structure. Natural gas consumption accounts for about 4 percent of the country\'s primary energy consumption. The percentage is about one sixth of the world\'s average. While natural gas consumption per capita is one eighth of the world\'s average of 508 cubic meters per year. According to the country\'s development plan, a third west-to-east gas pipeline will be built, which is expected to transfer more than 20 billion cubic meters of natural gas annually from central Asia, he said. The first west-to-east pipeline, which pipes gas from Tarim Basin of Xinjiang to Shanghai, was designed to transmit 12 billion cubic meters of natural gas annually.