Design of a heat storage integrated fluidized bed reactor for solar-driven gasification of low-rank coal

Abstract

Applying the 10-kWt tower-type solar field, a novel latent heat integrated solar-driven fluidized bed reactor is developed for low-rank coal gasification. Based on a decoupling strategy to analyse the solar-thermal-chemical process in complicated 3D reactor, the current work focuses on the thermo-chemical response inside the reaction chamber. Employing equivalent solar heating boundaries obtained by the pre-study, a numerical model of the reactor, which simulates detailed thermo-chemical process in the fluidized bed gasification chamber, is formulated and validated with the literature data. With this model, the fluidized low-rank coal gasification process from the latent heat integrated solar reactor is investigated and compared with the benchmark solar reactor, whose equivalent heating boundaries come from the typical volumetric solar receiver. Results exhibit that the gas–solid flow patterns are positively influenced by the presence of latent heat, demonstrating a more stable bubbling fluidization state compared to those without latent heat integration. Meanwhile, the syngas composition and solar-to-fuel energy conversion efficiency can be significantly enhanced by the integration. Reactor equipped with latent heat storage (LHS) component maintains a relatively high hydrogen content of approximately between 68 vol% to 69 vol% and a considerable solar-to-fuel efficiency ranging from 75.2 % to 80.9 %.