Continuous toluene vapour photocatalytic deduction in a multi-stage fluidised bed

Continuous deduction of 1000 ppm toluene vapour in a multi-stage gas fluidised bed photoreactor was studied using TiO2 coated activated carbon (AC/TiO2) particles as the fluidising media. Due to the enrichment of the local toluene concentration, the efficiency of the toluene removal from the gas stream by the mass transfer-limited photocatalytic reaction was significantly improved using AC/TiO2 particles as the fluidising media. In the stage addition studies, the results showed that the toluene removal efficiency at steady state increased approximate 3–4% for every stage addition. The three-stage design effectively utilised the freeboard region and improved the toluene removal efficiency for approximately 37% when comparing to the single-stage system. Using SiO2 powders as fluidising media could enhance the light utilisation by light scattering and promotes the toluene deduction during the initial to steady toluene deduction period.

Graphical Abstract1000 ppm toluene was continuously deducted in a multi-stage gas fluidised bed photoreactor using TiO2 coated activated carbon particles as the fluidising media. The toluene removal efficiency at steady state increased approximately 3–4% for every stage addition. The three-stage design effectively utilised the freeboard region and improved the removal efficiency for approximately 37% when comparing to the single-stage system.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► A multi-stage gas fluidised bed photoreactor is designed. ► 1000 ppm toluene is continuously deducted in the reactor. ► AC/TiO2 composite is used as the photocatalytic fluidising media. ► The toluene removal mechanisms are critically discussed. ► Fluidised light scattering SiO2 powders are loaded and their effects are discussed.