Establishment And Application Of Photocatalytic Reactor With Fluidized Bed-optical Fibers System

The optical transmission efficiency of the present photo catalytic reactor is low and the contact of photon-reactants-catalyst is bad. In view of this situation, this paper aims at designing a new-type photocatalytic reactor to take a good contact among photo-reactants-catalyst. A fluidized-bed optical fiber photocatalytic reactor is set up, the performance optimizing and testing of the photocatalytic reactor have been carried out. Furethermore, this reactor can be applied to do the research in the photocatalytic oxidation of formaldehyde.The research can be summarized as following.(1) Design of fluidized bed-optical fiber photo catalytic reactor, which includes the design of the overall gas route, and the light for optical fiber. The overall gas route consists of gas generator, gas mixing chamber, photo catalytic reactor and detection system. Fluidized-bed is cylindrical, the diameter of fluidized section is 10mm, and height is 100mm. The diameter and height of expanded section are both 16mm. The height of the other part of this reactor as following, the separate section is 120mm, and export section is 50mm. The totoal height of reactor is 426mm. The optical fibers are fixed on rubber plate. The light system is composed of 8 optical fibers in each plane, and the pitch between every two plane is 3.4mm. In gas route, diameter and the gas distribution plate have important impact to photo catalytic reactor. The diameter of the entrance pipe is 2mm and the gas distribution plate is 400 mesh.(2) The performance of new photo catalytic reactor has been optimized and tested. The flow pattern and light intensity of the fluidized-bed are main optimizing factors. If the catalyst particle is 60~120 mesh the total flow of gas is 180mL/min, and the static bed height of fluidized-bed is 68mm, the optimal flow pattern can be known, and then, the height of fluidized-bed can be measured as 90mm. Choosing acetone and TCE as the object pollutants, under optimal conditions, the conversion of acetone is 69.9%, quantum efficiency is 3.46%, and steady-state reaction rate is 3.98μmol of acetone (g of catalyst)-1min-1.The conversion of TCE is 100%, the quantum efficiency is 4.66%, and the steady-state reaction rate is 4.55μmol of TCE (g of catalyst)-1min-1. Compared to traditional fixed optical fiber photo catalytic reactor and fluidized-bed photo catalytic reactor, the new reactor has more excellent photo catalytic properties.(3) The application of this new reactor to degrade formaldehyde. The conversion of formaldehyde can reach 85.71%, the quantum efficiency is 7.95%, and steady-state reaction rate is 6.44μmol of formaldehyde (g of catalyst)-1min-1.