Catalytic reactor

A catalytic reactor having a mixing section connected to a downstream reaction section containing a catalyst to promote a reaction of oxygen and a hydrocarbon fed to the catalytic reactor. The mixing section is provided with a flame arrestor to prevent a stable flame from propagating should any reaction of oxygen and hydrocarbons occur during mixing. The flame arrestor permits flow in both axial and radial directions to promote mixing. Baffle elements and a downstream static mixer can also be used. The catalyst is preferably in the form of monolithic blocks enclosed by a ceramic tube that is maintained as a unitary catalyst assembly that can be removed for replacement and installation of the catalyst as a single unit.