HEAT EXCHANGE REACTOR

A reactor comprising: a shell enveloping: a reaction zone, a heat transfer zone, and an isolation zone; the shell provided with: a feed fluid inlet, a product fluid outlet, and an isolation fluid inlet. The reaction zone provides fluid communication between the feed fluid inlet and the product fluid outlet, and extends though the heat transfer zone and the isolation zone. The isolation zone is located between the heat transfer zone and the product fluid outlet; wherein a feed fluid as it flows from the feed fluid inlet, through the reaction zone is heated by a heat transfer fluid flowing through the heat transfer zone and reacts to form a product fluid that flows out of the shell through the product fluid outlet. A purge fluid in the isolation zone is at a positive pressure relative to a pressure of the heat transfer fluid flowing through the heat transfer zone.