Laboratory study of pollutant emissions from wood charcoal combustion for indoor space heating in China

The climate in rural south China is characterized by hot summers and cold winters, and during the winter season, burning wood charcoal for local heating is widespread. The combustion exhaust is released directly indoors, which increases levels of indoor air pollution. This study evaluates household heating patterns and aims to identify strategies to reduce household air pollution associated with heating. The research choose a common type of wood charcoal fire pan and two kinds of wood charcoal in rural south China to conduct the real-time emission test with a Portable Emission Monitoring System (PEMS) under controlled laboratory conditions. The black wood charcoal (B) was ignited quicker and easier but emitted a large amount of CO while the white wood charcoal (W) was hard to ignite and the burning time was longer. The average burning rate of B could be up to 20±3 g/min, and that of W was about 10±3 g/min. The CO emission factor (EF) of B was 326±61 g/kg fuel, and the PM_2.5 EF was 1.5±1.1 mg/kg fuel. The CO EF of W was 138±68 g/kg fuel, and the PM_2.5 EF was 2.7±4.3 mg/kg fuel. This study shows that PM_2.5 mainly released in the lighting phase, which mainly came from the burning of wood sticks. The PM_2.5 emissions of charcoals were lower than PM_2.5 from current biomass cookstoves. However, the CO emission was very high at 326g/kg fuel, which was 2 times or even more than 20 times higher than some normal cooking stoves.