Patent ID: 8375717

Claim:
An apparatus to pre-heat gas, comprising: an electric line heater having electrical heating elements, wherein the electric line heater is connected to a gas inlet configured to allow gas to pass through the gas inlet, and wherein the electric line heater is configured to heat the gas as it flows through the electric line heater; a turbo gas expander positioned downstream of the electric line heater, wherein the turbo gas expander is configured to rotate in response to gas heated by the electric line heater that enters the turbo gas expander; a power generator having a rotating input shaft connected to the turbo gas expander, wherein the input shaft is configured to rotate in response to rotation of the turbo gas expander; and a power connection between the power generator and the electric line heater; wherein the power generator is configured to provide power to the electric line heater, wherein the electric line heater is configured to preheat gas flowing through the turbo gas expander to prevent formation of hydrates, wherein the rotation of the turbo gas expander is configured to provide input to power the power generator, and wherein the power generator is configured to convert the rotation of the turbo gas expander into a form of electrical energy to power the electric line heater.