(187n) Enhanced Gasification Reactor Designs for Maximizing Gas-Particle Interaction

Coal gasification is an endothermic chemical conversion process that converts coal and steam into syngas, a flammable mixture of hydrogen and carbon monoxide. However, the conversion efficiency of current gasification reactor technologies can be limited due to lack of gas-particle interactions within the reactor volume. To improve upon the current reactor technologies and maximize conversion within a given reactor volume, there is need to develop a reactor geometry that improves upon the fluidized bed and transports reactors without the issues of slugging, bypassing, and particle agglomeration that limit conversion.

In this work we discussed an effort to develop new fluidized bed gasification reactor designs that target maximization of reactor’s mixing and resulting syngas yield. More than 15 unique reactor designs were outlined and investigated using reactive-CFD simulations of the gasification process. The reactive-CFD simulations undertaken using MFiX - multi-phase simulation package enabled assessment of the gas-particle mixing behavior and syngas (CO and H2) yield in each of the reactor designs. A reactor design optimization task was undertaken to maximize the mixing and yield. Subsequently a lab-scale prototype of novel reactor design was fabricated using additive manufacturing techniques. Cold flow experimental tests were undertaken to validate the MFix simulation flow pattern and pressure drop. The results show an improvement of 3 % in production of syngas in a small scale reactor design of 140 cm height and 7.5 cm inside diameter. Such designs could be easily adopted as radically engineered modular systems, which have the potential to provide novel, cost-effective gasifiers.

Acknowledgements: The work presented here was funded under a Department of Energy Phase I SBIR contract DE-SC0013822. The authors would like to thank Dr. Arun Bose of National Energy Technology Laboratory. The authors would also like to thank Dr. Sarma Pisupatifrom Pennsylvania State University who participated as a consultant and supported on baselining the gasification conditions. The simulations under this project were undertaken using high-performance computing infrastructure of NSF Extreme Science and Engineering Discovery Environment (XSEDE) under allocation TG-SBR150001 of Dr. Srujan Rokkam.

Keywords: Coal gasification, Syngas, fluidized bed, MFix, reactive-CFD, mixing, additive manufacturing