The purpose of this study was to develop a $CO_2$ emission factor for refuse plastic fuel (RPF) combustion facilities, and calculate the $CO_2$ emissions from these facilities. The $CO_2$ reduction from using these facilities was analyzed by comparing $CO_2$ emission to facilities using fossil fuels. The average $CO_2$ emission factor from RPF combustion facilities was 59.7 Mg $CO_2$/TJ. In addition, fossil fuel and RPF use were compared using net calorific value (NCV). Domestic RPF consumption in 2011 was 240,000 Mg/yr, which was compared to fossil fuels using NCV. B-C oil use, which has the same NCV, was equal to RPF use. In contrast, bituminous and anthracite were estimated at 369,231 Mg/yr and 355,556 Mg/yr, respectively. In addition, the reduction in $CO_2$ emissions due to the alternative fuel was analyzed. $CO_2$ emissions were reduced by more than 350 Mg $CO_2$/yr compared to bituminous and anthracite. We confirmed that using RPF, an alternative fuel, can reduce $CO_2$ emissions.