Abstract: Reaction pumps and systems for hydrocarbon conversion are disclosed. A reaction pump for conversion of hydrocarbons has a housing, a reaction chamber enclosed by the housing, for containment of a hydrocarbon process fluid or liquid reactant, a mixing element disposed inside the reaction chamber, the mixing element coupled to a rotatable shaft, and a plurality of bearings receiving the shaft, each bearing being disposed outside the reaction chamber. At least one of the bearings is closest to the reaction chamber. A type of barrier is disposed between the reaction chamber and the closest bearing, for fluidically separating the reactant from the closest bearing. This barrier can take the form of a seal protection chamber. A system for hydrocarbon conversion includes the reaction pump and an additional circuit for cleaning and recycling process fluid or liquid.