Application of Spouting Fluidized Bed to PCLC to Improve Plant Efficiency

The main objective of this research program is to demonstrate an integrated coal-fueled PCLC facility at lab-scale (50KWth), and via design, fabrication, commission, hot testing and technical evaluation to address or significantly narrow the major near-term technical gaps that impede the application of PCLC into solid fuel and scale up. Central to the project are cost-effective iron-based oxygen carrier (OC), a pressurized spouted bed Reducer and several UKy-CAER¡¦s methods to improve overall reaction in the fuel reactor that will enable the following operation, performance, and economic objectives: 1. >95% CO2 capture, >97% combustion efficiency, 95% high purity CO2 2. Promotion of in-situ coal gasification and fuel utilization 3. Elimination of agglomeration of bed materials 4. High efficient on-line fuel ash separation (>90%) 5. 20% savings in capital cost and operation cost relative to baseline* *Baseline: NETL¡¦s Oxycombustion R&D Program: Chemical Looping Combustion Reference Plant (Fe2O3-based) Coal has been proven for many decades to be the lowest cost fuel for power generation. However, potential legislative controls on CO2 emissions are putting coal at a disadvantage in a carbon-constrained world because coal is the most carbon-intensive fuel for power generation. The conventional technologies for carbon reduction from existing coal-fueled power generation are add-ons requiring significant modification to existing structures and lay-out which could be cost intensive. We proposes a coal-fueled PCLC process integrated with a flue-gas turbine combined cycle for the next generation power generation to significantly improve plant efficiency and CO2 capture (43% HHV and 98%), in which the PCLC unit sever as an combustor to provide hot clean flue gas for large-scale power generation from coal combustion while capturing at least 95% of the CO2 from coal combustion at a low cost. This project will focus on UK-CAER¡¦s approach and methodology to address/ narrow the major technical gaps that impedes the application of CLC to solid fuel via a demonstration of 50 KWth PCLC facilities. The proposed PCLC combustor is enable of, (1) using a cost-effective iron-based oxygen carrier developed from solid waste of alumina industries to provide in-situ separated oxygen for full coal combustion and reducing operation cost, (2) using the elevated pressure system, pulverized coal and gas mixture of H2O/ CO2 to enhance the overall reaction rate and avoid high solid inventory, and (3) using appropriate physical arrangements of the fuel reactor with an spouted bed reactor to enable the sufficient fuel utilization and high purity of the CO2 stream, and with a draft tube configuration to provide strong mixing and rapid heating of the introduced pulverized coal to avoid OC-char agglomeration, and with a low-velocity bubbling bed serving as a device for on-line coal ash separation from the reduced oxygen carrier on the basis of density and particle size to avoid their accumulation in the system. The goals of this effort are to: 1) demonstrate an advanced coal-based power generation technology to potentially meet DOE¡¦s target of limiting the energy penalty to no more than a 35% increase in the cost of energy service, while capturing at least 90% of the CO2 released during the combustion of fossil fuels; 2) deliver a detailed engineering design on configuration layout, fabrication and construction of 50kWth integrated PCLC facility; 3) demonstrate and verify the UKy-CAER¡¦s technical approaches proposed for enhancing the overall reaction kinetics, emission mitigation, and avoiding agglomeration ; and 4) gather, collect, and evaluate information/data on reaction kinetics, OC durability, combustion efficiency / CO2 capture for next step scale up and commercialization of the PCLC technology. Accordingly, the following tasks will be performed in two budget periods by the UKy team: „« Budget Period 1 consists of process design, modification of the existing novel spouted bed facility at UKy-CAER and a cold model commissioning prior to hot testing. „« Budget Period 2 will conduct hot testing, data collection and performance evaluation on the 50 KWth PCLC facilities. Hot testing will focus on effectiveness of Red Mud OC, validation on appropriateness of the Reducer configuration designed for improving fuel utilization and the purity of CO2 stream, effectiveness of UKy-CAER¡¦s strategies (use of elevated pressure, pulverized coal and active red mud OC) to promote fuel conversion in continuous operation, validation of UKy-CAER¡¦s key technologies to adapt CLC to solid fuel (use of draft tube for pulverized coal injection to avoid OC/coal char agglomeration and effective on-line coal ash separation). Data and information on pollutant emission (sulfur and NOx) under PCLC operation will be collected for near future scale-up.