System for power recovery from quench and dilution vapor streams

A process for reducing pressure of a vapor stream wherein the vapor stream rotates a turbine wheel within the turbine to transmit rotational movement to an electrical generator and generate electricity. The resulting lower pressure vapor stream reduces a partial pressure of a hydrocarbon vapor or is injected into a reactor to reduce a temperature in the reactor. A recovered electric power measuring system comprises at least one processor; at least one memory storing computer-executable instructions; and at least one receiver configured to receive data from a sensor on an electrical powerline connected to a generator of a turbine, the turbine in fluid communication with a vapor stream wherein the turbine reduces the pressure of the vapor stream and the resulting lower pressure vapor stream is injected into a reactor to reduce a temperature in the reactor or to reduce a partial pressure of hydrocarbon vapor in the reactor.