Isinyathelo 1: Ukuhlanza igesi - igesi yemvelo ekhishwe noma igesi ehlobene nemithombo yegesi noma imithombo kawoyela ilethwa ukuhlanza usebenzisa amasu wokuhlunga. Ukungcola kususwe ngokuphelele kulesi sigaba, kushiye ngemuva kwengxube ye-hydrocarbon (i-methane, ethane, i-propane, nokunye).