WUHAN, Dec. 25 (Xinhua) -- Navigation authorities on the Yangtze River are promoting the use of gas to partially replace diesel to cut emissions on the river.

The Changjiang (Yangtze) National Shipping Group Co. Ltd has spent three million yuan (about 454,000 U.S. dollars) to modify a freighter, code named 8303, to enable dual fuel. The ship carries 20 cubic meters of liquefied natural gas.

The nitrogen oxides emissions of the renovated ship have been reduced by more than 80 percent, said the administration.

More diesel-fueled ships will be modified, it said.

As China's longest river, the Yangtze traverses western, central and eastern China and connects the prosperous coast with the less developed inland regions. It is one of the busiest rivers for freight traffic in the world.

China began to develop the Yangtze River Economic Belt in 2014 to boost concerted development in riverside areas, and environmental protection of the Yangtze was highlighted in the report of the 19th National Congress of the Communist Party of China.

Statistics from the Changjiang River Administration of Navigational Affairs show that 30,000 polluting and energy-intensive vessels have been dismantled and remodeled since 2010.

A total of 631 new energy freighters were approved from 2011 to 2015, cutting unit energy consumption by 20 percent, according to the administration.