PetroChina has begun work to triple the capacity of its Ningxia refinery to meet rising fuel demand in north-western China.

The capacity will be increased to five million metric tons a year or 100,000 barrels a day from the present 1.5 million tons of crude a year, according to Bloomberg citing parent company China National Petroleum.

The refinery expansion comes under one of the government’s key projects to improve fuel quality, China National said.

The expansion will be able to increase supply of high-quality oil products by 2.9 million tons annually, according to a previous report by environmental research unit of Ningxia refinery.

PetroChina will shut the existing 1.5 million ton-a-year plant in Ningxia, following the start of the new refinery.