A process is described for the production of chlorine by a catalysed gas-phase oxidation of hydrogen chloride with an oxygen-containing gas stream. In a specific embodiment, synthesis is performed in two or more passes. The drive shaft is supported in an unrotatable and axially slidable manner in a sleeve bearing that is supported rotatably in at least a select one of a bearing block or load bearing base supporting the spindle. The balloon is characterized by an ability to withstand a hoop stress of at least 35,000 psi without bursting.