Internally-circulating Fluidized Bed Reactor Using Thermal Storage Material for Solar Coal Coke Gasification

Abstract

Abstract A windowedreactor prototype of internally-circulating fluidized bed is tested and demonstrated at laboratory scale for steam gasification of coal cokeirradiated directly by concentrated Xe light from a 3-kW th sun simulator.The bed material is composed of particle mixture of coal coke and quartz sand. A coal coke of the bed material works as a carbonous feedstock, while quartz sand functions as a thermal storage/transfer medium inside the reactor. The fluidized bed reactor, having a transparent window due to incoming radiation of concentrated solar beam on the ceiling of the reactor, is designed to be combined with a solar reflective tower or beam-down optics.A potential of quartz sand in the internally-circulating fluidized bed reactor is evaluated forsteam gasification of coal coke by gasification performance (CO, H 2 and CO 2 production rates, carbon conversion, and light-to-chemical efficiency). The gasification performances for use of the particle mixture in the reactor are compared with that for use of coal coke particle.The fluidized bed of a particle mixtureincluding coal coke and quartz sand was gasified at lower temperature with a higher rate in comparison to that of a coal coke.Furthermore, a use of smaller and lighter coal coke particles were easily converted to gaseous species due to larger surface area as well as the gasification rates.