Ramgen, with the support of Dresser-Rand, is working to develop air and CO2 compressor products based on shock wave compression technology. This approach builds on well-established ramjet principles of aerospace propulsion, and represents a radical conceptual departure from conventional multi-staged, bladed turbo-compressors. Supersonic inlet technology produces air velocities above the speed of sound, creating shock waves that efficiently compress air or CO2. Shock wave compression has several advantages over conventional compression technologies: higher compression efficiency, higher single-stage compression ratios, opportunity for waste heat recovery, and lower capital cost.
This project was expanded in 2010 to include further development of the supersonic compression technology with a novel concept engine, the Integrated Supersonic Component (ISC) Engine. In separate research, Ramgen previously developed a high velocity combustor design uniquely suited for direct integration with the supersonic compression process. Working from lessons learned in developing the shock wave-based air and CO2 compressors and the successful demonstration of its AVC system, Ramgen will combine supersonic shock compression and AVC to produce a working ISC engine design. As the engine is designed and tested, the CO2 compressor will be advanced along its development path by incorporating the lessons learned in the aerodynamic design of the supersonic shock compression section of the ISC engine power wheel.
Important technical progress on shock wave-based compression has been achieved at a rapid pace because of access to supercomputers made possible by DOE. This enables the development of this revolutionary engine combined with further advancement of the CO2 compressor. Based on a computational fluid dynamics (CFD) modeling capability that is one of the most advanced in the world, the supersonic compression process can be incorporated into the power wheel and directly integrated with the combustion and expansion of the working fluid required for a highly efficient power generation cycle.
Ramgen will employ classic engineering strategies to execute a successful CO2 compressor demonstration program using a 13,000 horsepower (hp) unit. Ramgen’s technical team will design and analyze the CO2 compressor demonstration rig in deterministic steps—including Conceptual Design Review (CDR), Preliminary Design Review (PDR), and Final Design Review (FDR)—with an increasing level of detail at each step. The design process incorporates a number of decision gates along with risk assessment and risk reduction tasks. The program is also intended to produce early-stage preliminary aero flow path validation data. The project will feature several risk reduction efforts, including a critical factor investigation for designing a supersonic CO2 compressor, performance model update, and a risk closure plan. Upon completion of the engineering design, the CO2 compressor demonstration test rig will be fabricated and assembled. The final compressor testing step will be to operate a 13,000 hp CO2 compressor rig at a suita ble site.
The ISC engine development will include system design and construction of three increasing-scale models: (1) a 1.5 megawatt (MW) proof-of-concept model for initial testing; (2) a 2.5 MW workhorse model that incorporates a low pressure turbine stage to achieve the full efficiency capability of the system; and (3) a 5 MW commercial-scale prototype for field testing that incorporates the lessons learned from the proofof-concept and workhorse units. The workhorse engine and the 5 MW scale prototype iterations are serialized sufficiently in time so as to allow lessons learned in the design and assembly of each engine to be applied to the next iteration. Performance testing of the 5 MW prototype will further provide critical experimental evidence confirming the effects of system physical scaling on performance.
The mission of the U.S. Department of Energy’s National Energy Technology Laboratory (DOE/NETL) Carbon Capture Program is to develop innovative environmental control technologies to enable full use of the nation’s vast coal reserves, while at the same time allowing the current fleet of coal-fired power plants to comply with existing and emerging environmental regulations. The Carbon Capture Program portfolio of carbon dioxide (CO2) emissions control technologies and CO2 compression is focused on advancing technological options for the existing fleet of coal-fired power plants in the event of carbon constraints. This project is one of several program projects that were selected by DOE to receive funding from the American Recovery and Reinvestment Act (ARRA). These projects will accelerate carbon capture research and development for industrial sources toward the goal of cost-effective carbon capture and storage (CCS) within 10 years.
Studies conducted by DOE have revealed the high cost and energy requirements that exist for CO2 compression. The CO2 captured from a power plant will need to be compressed to 1,500 to 2,200 pounds per square inch absolute (psia) to be effectively transported via pipeline and injected into an underground sequestration site. The energy requirement for compression can be as much as 7.5 percent of the electrical output of a subcritical pressure, coal-fired power plant, which represents a potentially large auxiliary power load on the overall power plant system. Reduction of the compression cost and energy requirements will be beneficial to the overall efficiency of CCS for both utility and industrial applications.
Ramgen Power Systems (Ramgen) has developed an advanced CO2 compression technology utilizing supersonic shock waves that can lower the cost of CCS and reduce greenhouse gas emissions. Integrated with the development of the CO2 compressor, a novel concept engine for power generation will be developed that combines shock wave compression and advanced vortex combustion (AVC) to offer significant cost savings over conventional designs. This innovative engine shows potential as an important tool for load leveling with renewable power generation operations, further reducing emissions of greenhouse gases.
Supersonic shock wave compressors are projected to reduce the volume of space needed in a power plant compared to that needed for the compressor section of a conventional turbine, while producing energy more efficiently and cost-effectively. Improved operating efficiency results from the integration of recovered heat from the compressor into the plant cycle, which can result in an approximate operational cost savings of 18 percent. The capital cost requirement is reduced by approximately 50 percent with a supersonic shock wave compressor. This technology is also projected to increase the pressure of captured CO2 prior to geological sequestration, lowering sequestration costs.
An additional important benefit of expanding the work in this project is that the ISC engine will have the capability to generate electricity efficiently using dilute methane gas released during coal mining operations and from landfills. This unique capability is based on the combustion of the air/methane mix occurring virtually instantaneously following its supersonic compression. This eliminates the possibility of premature ignition or detonation of the fuel-air mixture. Using this methane as a fuel could mitigate its effect as the second largest anthropogenic greenhouse gas contributor, after CO2, to global warming.
The project goal is the integrated development of high-efficiency, low-cost CO2 compression using supersonic shock wave technology to significantly reduce capital and operating costs associated with carbon capture, utilization, and storage, and of the ISC engine to lower capital and operating costs and increase system efficiencies on the order of 50 percent.
The project objectives are detailed in three Phases. Phase 1 objectives were to show a large scale (13,000 hp) CO2 compressor could be demonstrated with the resources, time and facility capabilities available and to develop the design of the test facility as well as the CO2 compressor test article. Phase 2 objectives are to complete the design and build of the test facility design and the design, build and test of two CO2 compressor configurations for the 13,000 hp proof-of-concept, supersonic shock wave CO2 compressor. During this Phase Ramgen will also design, manufacture, build and test a Proof-of-Concept engine using Ramgen technology and a work horse unit used to improve the performance of the engine configuration. The key aerodynamic processes and refinements learned will be applied to the CO2 compressor rotor for optimization and performance improvement on the CO2 compressor rotor. Phase 3 objectives are to design, build and test an engine capable of higher performance and with the capability to burn low BTU fuels like coal bed methane found in coal mines. The engine activities will provide design rules and refine performance scaling for the CO2 compressor rotor.
Click to view Presentations, Papers, and Publications