Heat transfer and gas-solid behaviors in pneumatic transport reactor used of carbon capture system

Abstract

A pneumatic transport reactor can be used for continuous carbon capture processes using a dry sorbent because it can handle large quantities of flue gas. To design efficient reactors, it is necessary to understand the internal characteristics of a reactor with a complicated gas-solid flow. Computational fluid dynamics using an Eulerian-Eulerian approach was adopted to simulate gas-solid two-phase flow to better understand the gas-solid behaviors and heat transfer characteristics in a pneumatic transport reactor. Numerical simulations were used to analyze the pressure difference, solid mass flux, and heat transfer coefficient. The results showed that the gas-solid behavior was unstable and that localized particle flow affects the heat transfer characteristics. The degree of particle mixing near the solid return inlet was lower than that at greater heights within the reactor; in the inlet region, the heat transfer coefficient is not uniform in accordance with the non-uniformity of solid particle behavior.