In order to reduce the amount of carbon dioxide (CO2) greenhouse gases released into the atmosphere, significant progress has been made in developing technology to sequester CO2 from power plants and other major producers of greenhouse gas emissions. The compression of the captured carbon dioxide stream requires a sizeable amount of power, which impacts plant availability, capital expenditures and operational cost. Preliminary analysis has estimated that the CO2 compression process reduces the plant efficiency by 8% to 12% for a typical power plant. The goal of the present research is to reduce this penalty through development of novel compression and pumping processes. The research supports the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) objectives of reducing the energy requirements for carbon capture and sequestration in electrical power production. The primary objective of this study is to boost the pressure of CO2 to pipeline pressures with the minimal amount of energy required. Previous thermodynamic analysis identified optimum processes for pressure rise in both liquid and gaseous states. At elevated pressures, CO2 assumes a liquid state at moderate temperatures. This liquefaction can be achieved through commercially available refrigeration schemes. However, liquid CO2 turbopumps of the size and pressure needed for a typical power plant were not available. This paper describes the design, construction, and qualification testing of a 150 bar cryogenic turbopump. Unique characteristics of liquid CO2 will be discussed.
A Review of Pathways to Carbon Neutrality from Renewable Energy and Carbon Capture