Evaluation of the Contribution of the Building Sector to PM2.5 Emissions in China

In recent years, China has experienced severe air pollution with adverse health consequences as a result of pollutants emitted by activities related to its rapid economic development and urbanization. One pollutant of growing concern in China is PM2.5, inhalable fine particulate matter linked to serious respiratory diseases, lung cancer, cardiovascular problems, birth defects and premature death. PM2.5 is directly emitted as the non-combustible materials from point primary sources including combustion processes (e.g. diesel engines, coal boilers in power plants), but can also be formed through secondary sources through chemical reactions with gaseous pollutants or precursors such as SO₂ and NOx that are released into the atmosphere. Buildings directly generate PM2.5 emissions by burning coal for end-uses such as heating, and also indirectly generate pollutants by consuming electricity that is generated predominantly by coal-fired power plants. This study therefore focuses on primary PM2.5 emissions emitted directly as a result of coal combustion to generate heat and electricity for residential and commercial buildings.

In this study, we quantify the current and potential contribution of China's building sector to direct primary and indirect PM2.5 emissions and co-benefits of key pollution reduction strategies of energy efficiency, fuel switching and pollution control technologies on PM2.5 emissions reduction. We use a bottom-up end-use accounting model to model residential and commercial buildings' coal demand for heating and electricity demand in China's Northern and Transition climate zones from 2010 to 2030. The model is then used to characterize the current coal-based heating (e.g., district heating, combined heat and power generation, small-scale coal-fired boilers) and power generation technologies to estimate direct and indirect PM2.5 emissions. Model scenarios are developed to evaluate and compare the potential co-benefits of efficiency improvements, fuel switching and pollution control technologies in reducing building-related direct and indirect PM2.5 emissions. An alternative pathway of development in which district heating is introduced to China's Transition zone to meet growing demand for heat is also modeled to evaluate and quantify the potential impact on PM2.5 emissions.