Development of Allothermal Rotary Gasifier with CO2 Acceptor for Hydrogen Production from Coal Waste and Biomass

Gasification technology is highly flexible and can be applied to most carbon-containing materials including coal waste, municipal solid waste, sewage sludge, and biomass, and has been considered as an ideal core technology of the zero-emission poly generation energy plant. However, the challenge still resides in making it cost-competitive, thermally efficient, and environmentally friendly. Also, for a wide application and deployment of clean gasification technologies, a simpler and easier-to-operate system is recommended. About 30% of U.S. coal-fired generation capacity has been retired since 2010 and the mines providing the fuel are affected as well. Coal waste from the abandoned mines can represent environmental liability and the abandoned mine land sites are often overrun by invasive plant species and frequently bordered by poorly managed forests. These problems can present an opportunity to develop clean fuel technology by utilizing unwanted carbonaceous material and producing value-added products. Also, the technology development and deployment in the proximity of the coal waste and biomass sources can revitalize local underserved economies while reducing transportation needs and carbon footprint. REI proposes to develop a mobile, affordable, modular, and continuous syngas production process with a rotary kiln gasifier that combines indirect heating and CO2 acceptor utilizing inexpensive carbonaceous materials to provide feedstock for value-added processes, such as hydrogen production. With tightly integrated heat recovery and management module and mineral addition, the proposed rotary kiln gasifier will produce hydrogen-enriched syngas. In Phase I, REI will develop a process model for rotary kiln gasifier with key heterogeneous and homogeneous reactions based on the existing kiln reactor model and perform bench-scale testing in parallel, to implement key operation impacts into the process model. REI will also perform material characterization to employ the actual properties of the fuels sourced from the target location and guide the model development as well as testing effort. The detailed threedimensional computational fluid dynamics modeling with all the key processes will also be performed to validate the approach and evaluate the scale-up design. Then, REI will conclude Phase I with a carbon lifecycle analysis and economic evaluation in the target plant site. Through pilot-scale reactor development and testing, and full-scale demonstration planned for Phases II and III of the proposed program, the mobile, modular, continuous, and low-cost gasifier will be commercialized to produce hydrogen-enriched syngas from coal waste and biomass. This will help the local underserved community and relieve environmental concerns incurred by coal waste and invasive scrub species while facilitating hydrogen economy.