Electrical power generated by carbon dioxide gas pressure letdown

A method comprising:

• receiving, by an inlet pipe, carbon dioxide from a carbon dioxide pipeline;
• flowing at least a first portion of the carbon dioxide from the inlet flow line to a first flow line, wherein the flow-through electric generator is coupled to the first flow line;
• flowing, by the first flow line, the first portion of the carbon dioxide to a radial inlet of a turbine wheel disposed within a hermetically sealed housing of a flow-through electric generator coupled to the first flow line, wherein the turbine wheel rotates in response to expansion of the first portion of the carbon dioxide flowing into the radial inlet of the turbine wheel and out of an outlet of the turbine wheel, wherein the hermetically sealed housing prevents the first portion of the carbon dioxide from escaping the radial inlet of the turbine wheel;
• prior to flowing the first portion of the carbon dioxide to the radial inlet of the turbine wheel of the flow-through electric generator, reducing a pressure of the first portion of the carbon dioxide to a specified pressure and heating, by a heater coupled to the inlet flowline, the carbon dioxide to a specified temperature upstream of the first flow line and the second flow line, such that the first portion of the carbon dioxide entering the flow-through electric generator at the specified pressure and the specified temperature is in a gaseous state;
• generating electrical power by the flow-through electric generator in response to the first portion of the carbon dioxide flowing across the turbine wheel, wherein the electrical power is generated upon rotation of a permanent magnet rotor surrounded by a stator, wherein the permanent magnet rotor and the stator are disposed within the hermetically sealed housing, wherein the permanent magnet rotor is coupled to the turbine wheel for rotating with the turbine wheel;
• after generating the electrical power, flowing the first portion of the carbon dioxide from the flow-through electric generator to an outlet pipe connected to a carbon dioxide pipeline network;
• flowing at least a second portion of the carbon dioxide from the inlet flow line to a second flow line, wherein the second flow line provides an alternate flow path for the carbon dioxide around the first flow line;
• and
• recombining the first portion of the carbon dioxide from the first flow line with the second portion of the carbon dioxide from the second flow line, downstream of the flow-through electric generator.

A system comprising:

• an inlet pipe connected to a carbon dioxide pipeline flowing carbon dioxide;
• a first flow line coupled to the inlet flow line to receive at least a first portion of the carbon dioxide from the inlet flow line;
• a second flow line coupled to the inlet flow line to receive at least a second portion of the carbon dioxide from the inlet flow line and provide an alternate flow path for the carbon dioxide around the first flow line;
• an outlet flow line coupled to the first flow line and the second flow line to recombine the first portion and the second portion of the carbon dioxide from the first flow line and the second flow line, respectively;
• a first pressure control valve coupled to the first flow line, the first pressure control valve configured to reduce a pressure of the first portion of the carbon dioxide to a specified pressure;
• a heater coupled to the inlet flow line, the heater configured to heat the carbon dioxide to a specified temperature upstream of the first flow line and the second flow line, wherein the carbon dioxide at the specified pressure and the specified temperature is in the gaseous state;
• a flow-through electric generator coupled to the first flow line, the flow-through electric generator comprising:
• a hermetically sealed housing;
• a turbine wheel disposed within the hermetically sealed housing and configured to receive the first portion of the carbon dioxide from the first flow line and rotate in response to expansion of the first portion of the carbon dioxide flowing into a radial inlet of the turbine wheel and out of an outlet of the turbine wheel;
• a permanent magnet rotor disposed within the hermetically sealed housing and coupled to the turbine wheel and configured to rotate with the turbine wheel;
• and
• a stator disposed within the hermetically sealed housing and surrounding the permanent magnet rotor, wherein the flow-through electric generator is configured to generate electrical power upon rotation of the rotor within the stator, wherein the hermetically sealed housing is configured to prevent the carbon dioxide from escaping the radial inlet of the turbine wheel;
• and
• a second pressure control valve coupled to the second flow line, the second pressure control valve configured to provide a constriction of an adjustable size for the second portion of the carbon dioxide flowing in the second flow line, wherein the outlet flow line is connected to a carbon dioxide pipeline network, and the outlet flow line is configured to receive the carbon dioxide that has expanded through the flow-through electric generator.