Question

(a) Explain the major differences between producer gas and water gas.

(b) Explain why the presence of even a small amount of H2 can substantially expedite the reaction of CO-O2 mixture by using chemical kinetics analysis.

Answer 1

The key difference between water gas and producer gas is that the water gas contains flammable gases whereas the producer gas contains both flammable and non-flammable gases. Both water gas and producer gas are mixtures of several gases. Water gas contains carbon monoxide and hydrogen gases.

As the processes of ignition and combustion of H 2 –CO–O 2 (air) mixtures follow the chain mechanism whose carriers are active O and H atoms and OH radicals , the reaction mechanism has to ensure a correct description of the time evolution of these species. The profile of the mole fraction of O atoms versus time, which was measured in [20] behind the shock wave reflected from the end face of the shock tube in an extremely lean hydrogen–oxygen mixture under conditions where no ignition occurs and the chain initiation process prevails is compared inFig. 3 with the results calculated by the kinetic mechanisms [2], [4], and [5] and by the present model. ..