TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The minor amount of contaminants comprises 1-15 mol.% on dry basis of the CO2 rich gas stream. The substantially pure O2 comprises a 95% purity or greater amount of O2. The ratio of O2 to CO2 rich gas stream is slightly below the stoichiometric value in order to control residual hydrocarbons in the purified CO2 to be 10-10000 ppm. The catalyst of the catalytic oxidizer is a platinum metal or a palladium metal on a support. The ratio of O2 to CO2 rich gas stream is slightly above the stoichiometric value in order to completely destroy all hydrocarbons and control residual O2 in the purified CO2 to be 10-1000 ppm.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The CO2 rich gas stream is obtained from a membrane water-gas shift reactor, a membrane reformer, a sorbent enhanced reformer or a reverse selectivity polymeric membrane. The combined O2/ CO2 rich gas stream injected into the catalytic oxidizer is injected at a temperature of 300-700 degrees C. The process further comprises injecting natural gas into the catalytic oxidizer along with the O2/CO2 rich gas stream. The CO2 rich gas stream is generated from a hydrogen generator in combination with either a membrane water-gas shift reactor, a membrane reformer, a sorbent enhanced reformer or a reverse selectivity polymeric membrane. The process comprises: injecting the combined O2/CO2 rich gas stream into a catalytic oxidizer reactor having an inlet and an outlet and one or more beds of a catalyst that is disposed between the inlet and outlet, where the beds of catalyst being selective for combusting the flammable contaminants contained in the combined O2/CO2 rich gas stream in order to combust the contaminants contained in the combined O2/CO2 rich gas stream and produce a hot purified CO2 rich gas stream, the combined O2/CO2 rich gas stream is injected into the catalytic oxidizer reactor at the inlet of the catalytic oxidizer reactor and at a temperature that is sufficient to allow for the combustion of the contaminants in the CO2 rich gas stream; passing the hot purified CO2 rich gas stream through one or more heat exchangers in order to capture the heat from the hot purified CO2 rich gas stream for use to either raise steam, superheat steam, reforming of hydrocarbons, preheat natural gas and steam mixtures used as feedstock for hydrogen production, or preheat combustion air for the hydrogen generator, or provide heat for the regeneration of CO2 sorbent beds; further passing the heat exchanged purified CO2 rich gas stream to a water separator in order to condense and remove water from the heat exchanged purified CO2 rich gas stream and produce a purified CO2 rich gas stream; and recycling a portion of the purified CO2 rich gas stream to the combined O2/CO2 rich gas stream in order to adjust and control the temperature at the inlet and outlet of the catalytic oxidizer reactor and withdrawing the remaining portion of the purified CO2 rich gas stream for further use.