... Separation for many valves and columns, TCD system analysis H2, O2, CH4, CO, C2H6, CO2, H2S, C2H4, C3H8, C3H6, ... ON, C6+ was flow back to TCD, examined. Components O2, N2, CH4, CO, CO2 and C2 flow out ... ON to OFF. Before CO2 and C2 flowing out, O2, N2, CH4, CO flow into chromatographic column 13X, ... Switch the valve V3 from ON to OFF, components O2, N2, CH4 and CO will be detected. Analysis process ...