Hydrodynamic study on the riser of chemical looping hydrogen production system with multiple fluidized bed reactors

Abstract

Chemical looping technology is an available way for hydrogen production with low penalty energy for improving gas purity and CO2 is captured simultaneously. Understanding the operation and flow behavior is crucial for development of chemical looping hydrogen production. Experimental investigations of the system with dual interconnected fluidized bed reactors were carried out and presented in this work. The results indicated the system reached stable operation with current design. Influence of superficial gas velocity on the pressure distribution was examined and the corresponding mass inventory in the reactor was also analyzed. It showed that the relative pressure decreases with the increase of riser fluidization velocity and more particles will be transported to the fuel reactor from riser. The pressure curve fluctuated in sinusoidal shape as expected. It was better to make a large fuel reactor which holds most of solids and contributed to the stability. A tanks-in-sires model was utilized for analyzing the pressure evolution in the riser, which was less time consumed compared with computational fluid dynamic method. It showed the obvious phase shift of pressure drop along height. Also, the force balance of a particles was analyzed for predicting the mass inventory of riser and this method overcame the insufficient of measurement technology. The influences of solid circulating rate and gas velocity were obtained and be investigated further. This is a feasible way for quick prediction of flow behavior in the riser for both the design and operation under a certain operating condition.