Monitoring light hydrocarbons in Brazilian coal mines and in confined coal samples

►Procedures to determine LHCs levels in the air of coal mines and in confined coal. ►Study of five mines under operation (3 underground and 2 surface) in southern Brazil. ►Methane levels varying from 3 ppm to 27% in the underground mines. ►Surface mines presented narrow concentration range (3 ppm to 470 ppm). ►Among LHCs methane is desorbed in higher concentrations from confined coals.