Technical Study On Oxygen-enriched Waste Incineration Generation And Process Simulation Of Flue Gas Purification

In order to achieve municipal solid waste(MSW)’s clean-incineration and maximallyeliminate the threat of secondary pollution completely, under the purpose of achieving“Recycle, Reduce, Reuse”of waste disposal, based on oxygen-rich coal powergeneration technology, a new type of waste incineration technology-pure oxygen meltingincineration technology of municipal solid waste in rotary kiln is put forward thereby.Taking a350t/d rotary kiln waste incinerator using the oxygen-enriched meltingincineration technology as an instance, further study are carried out.Oxygen-enriched melting waste incineration technology uses the high purity oxygenproduced by the air separation units, instead of air, together with the MSW to realize hightemperature melting incineration inside the rotary kiln. The high temperature flue gasproduced during the incineration is recycled in the waste heat boiler and sent into thesubsequent flue gas compression and liquefaction devices for purification and CO2capturing. The recycle system of free flue gas cancels the construction of the chimneyand realizes complete capture of burning products and near zero emissions. Athermodynamic analysis is carried out of the whole rotary kiln melting system in thepaper. Results show that MSW can maintain stable combustion without adding anyauxiliary fuel and it can reach the melting temperature in the rotary kiln tail.In addition,the parameters of this pure oxygen melting incineration MSW rotary kiln are determined.And on the platform of Aspen Plus, the thermodynamic equilibrium analysis of MSWmelting incineration system was performed. Simulation results show that the combustiontemperature can be up to1800℃of pure oxygen, instead of air, used in the meltingincineration system of a rotary kiln, which is enough to melt any form of junk residue, soit further verify the results of heat balance calculation.Based on the technology of desulfurization and denitration of oxygen-enrichedcoal-fired flus gas with CO2capture, a new type of waste incineration flue gaspurification technology is put forward and the model for simulation of the whole flue gaspurification process is established and calculated using the software Aspen Plus. Thesimulation results show that almost all HCl and SO2can be removed within the entireflue gas compression and liquefaction process and the denitration efficiency is above 90%. At the same time, part of acid liquor can be recovered in the process of the flue gaspurification. The flue gas of350t/d rotary kiln pure oxygen melting incineration wastesystem is disposed by combined deacidification process,306kg dilute sulfuric acid of40%mass concentration and51kg diluted nitric acid of15%mass concentration can berecovered each hour.At last, the economy analysis is carried out of the whole oxygen-enriched meltingincineration system. The results showed that the turbine power output is7.67MW. Thepower consumption of the air separation unit and flue gas compression equipment whichare the energy-intensive equipment of all auxiliary equipments account for above50%ofthe total generating capacity. Power generation efficiency of the whole power plant is29.13%. After comprehensive considering other auxiliary energy consumption, the netelectrical efficiency is11.54%, and the net output power is3.04MW. So, there is no needto buy electricity from the grid. If the heat of generating oxygen by air separation couldbe recycled, net output power can increase by0.55percentage point, because this part ofthe heat can exclude a part of bled steam of the turbine.