From 2014, Baoji City began to implement natural gas projects and vigorously implemented coal-to-gas conversion projects. Baoji Cigarette Factory is one of the major backbone enterprises of the China National Tobacco Corporation and is the largest cigarette manufacturer in the northwest region. In line with the environmental protection policy, Baoji Cigarette Factory implemented the "coal to gas" project. Through bidding activities, it cooperated with ZOZEN boiler to dismantle 35 tph coal-fired boilers and install 25 tph SZS gas-fired steam boilers to improve boiler operation levels and reduce air pollutant emissions.
After the implementation of coal-fired boilers to gas-fired replacement project, after monitoring, the sulfur dioxide, nitrogen oxides and soot in the exhaust gas of the gas-fired boiler are all in compliance with the special emission limit requirements in the "Emission Standard of Boiler Air Pollutants" (GB13271-2014).
— Shanxi Zhongyan Industrial Co., Ltd. (Baoji Cigarette Factory)