反应Ⅰ:CO(g)+3H2(g)CH4(g)+H2O(g) △H1=-206.4kJ•mol-1
反应Ⅱ:CO2(g)+4H2(g)CH4(g)+2H2O(g) △H2
反应Ⅲ:CO2(g)+H2(g)CO(g)+H2O(g) △H3=+41.2kJ•mol-1