Development Status of a Coal Powered Oxy-fired Pressurized Fluidized Bed Combustor with CO_2 Capture and Purification

摘要

Oxy-fired Pressurized Fluidized Bed Combustor (Oxy-PFBC) technology is under development as a method to enable the use of coal for electricity generation while capturing the CO_2 and other emissions at a cost that is significantly less than the current commercially deployed post-combustion capture technologies. This paper discusses the features of the Oxy-PFBC, commissioning test results for the 1 MW_(th) pilot scale system, techno-economic analysis results, and development and commercialization plans. The plant was successfully commissioned in April, 2017, demonstrating coal ignition and burning, and is now ready for performance testing. The Oxy-PFBC is a 1 MW_(th) pilot scale system installed at the Natural Resources Canada facilities in Ottawa, and includes a CO_2 Purification Unit (CPU) from Linde. The combustor utilizes elevated pressure and a heat exchanger in the fluidized bed to reduce the combustor size and cost, while oxy-combustion enables lower cost CO_2 separation by producing an exhaust stream that is primarily CO_2 and water vapor. The CPU operates at elevated pressure and utilizes a direct contact cooler for HCl and water vapor removal, followed by a Linde LiCONOX unit to remove SO_x and NO_x, and a De-Oxo Reactor to remove excess oxygen. The carbon capture penalty (increase in cost of electricity) for current CO_2 capture technology is approximately 70%. Current predictions indicate the Oxy-PFBC can reduce the carbon capture penalty by more than half, to 30%, and capture up to 98% of CO_2 emissions. These results assume no economic benefit of the captured CO_2. The system could achieve no net increase in electricity cost through the sale of CO_2 at $30/ton. The current development plans include completion of the initial phase of pilot scale testing by mid-2017, followed by technology upgrades to the pilot plant and testing of these upgrades by the end of 2017. Preliminary planning for a 30 MW_(th) large pilot plant is underway with potential program start in 2018 and operation by 2021.