Numerical Simulation And Optimization Of Anaerobic Reactor

The startup, operation characteristics and removal performance for organic matter of UASB and IC reactor were studied. While the interdisciplinary advantage of chemical engineering, environmental science and computer technology was not applied to research hydrodynamic characteristics of the reactors, which was the basis of optimization design and amplification of these reactors.Therefore 2-dimensional distributions of gas-liquid two-phase flow in UASB and IC reactor were studied using Fluent technology. The effect of flow field in UASB reactor under different angle of three-phase separator and OLR was investigated; and the QIC in IC reactor under different Dr/D, OLR and H/D was investigated. The main research contents and conclusions are as follows:(1) The numerical simulation of UASB reactor1) When the angle of three-phase separator was 50o, the effect of flow field under different OLR(4, 5, 6, 7kg COD/(m3·d)) was studied. When OLR was 5 kg COD/(m3·d), liquid in rector did not spill out, then gas-liquid mixed distribute uniformly in flow field and efficiency for mass transfer was to achieve maximum.2) When the OLR was 5 kg COD/(m3·d)), the effect of flow field under different angles of three-phase separator(45o, 50o, 55o, 60o) was studied. When angle of three-phase separator was 50o, turbulence intensity in reactor bottom was strong and biological sludge-wastewater contact was increased well. As gas in settling zone was little, the efficiency of solid-liquid separation was good.(2) The numerical simulation of IC reactor1) When Dr/D(0.032, 0.049, 0.065, 0.081, 0.097, 0.114) was 0.081, a maximum value of QIC(0.0079m3/h) was reached under conditions of OLR(11.52 kg COD/(m3·d)) and H/D(5);2) When OLR(8.64, 10.08, 11.52, 12.96, 14.40, 15.84, 17.28, 18.72, 20.16 kg COD/(m3·d)) was 12.96 kg COD/(m3·d), a maximum value of QIC(0.0099m3/h) was reached under conditions of H/D(5) and Dr/D(0.081). Correlation of QIC and biogas production was gained by fitting analysis;3) When H/D(3, 4, 5, 6, 7) was 3, a maximum value of QIC(0.011 m3/h) was reached under conditions of OLR(17.28 kg COD/(m3·d)) and Dr/D(0.081).